fix build (linux api server): Remove srcs that moved to sparkd

In preparation for the first deployment of the "development" branch.

.devcontainer/Dockerfile

@@ -0,0 +1,122 @@
+FROM ubuntu:22.04
+
+ARG DEBIAN_FRONTEND=noninteractive
+
+# Note installations that take a while (more than 10s)
+
+RUN apt-get update
+RUN apt-get install -y ca-certificates
+RUN apt-get install -y ccache
+RUN apt-get install -y curl
+RUN apt-get install -y fish
+RUN apt-get install -y gdb
+# git-all: ~250s
+RUN apt-get install -y git-all
+RUN apt-get install -y gnupg
+# liblttng-ust-dev: ~30s
+RUN apt-get install -y liblttng-ust-dev
+RUN apt-get install -y libssh2-1-dev
+RUN apt-get install -y locales
+RUN apt-get install -y ninja-build
+# openssh-server: ~40s
+RUN apt-get install -y openssh-server
+RUN apt-get install -y pkg-config
+RUN apt-get install -y software-properties-common
+RUN apt-get install -y sudo
+RUN apt-get install -y tzdata
+RUN apt-get install -y vim
+RUN apt-get install -y zip
+
+# Python: ~30s
+RUN apt-get install -y \
+   python3-pip \
+   python3-venv \
+   && python3 -m pip install --upgrade pip
+
+# GCC
+ARG gcc_major=13
+RUN \
+   add-apt-repository ppa:ubuntu-toolchain-r/test \
+   && apt-get update \
+   && apt-get install -y g++-$gcc_major
+
+# Clang
+ARG clang_major=17
+RUN \
+   curl -fsSL https://apt.llvm.org/llvm-snapshot.gpg.key 2> /dev/null \
+   | gpg --dearmor - \
+   | tee /usr/share/keyrings/llvm-snapshot.gpg > /dev/null \
+   && echo "deb [signed-by=/usr/share/keyrings/llvm-snapshot.gpg] http://apt.llvm.org/$(lsb_release -cs)/ llvm-toolchain-$(lsb_release -cs)-$clang_major main" \
+   | tee -a "/etc/apt/sources.list.d/llvm.list" \
+   && apt-get update \
+   && apt-get install -y \
+   clang-$clang_major \
+   clang-format-$clang_major \
+   clangd-$clang_major
+
+# CMake
+RUN \
+   curl -fsSL https://apt.kitware.com/keys/kitware-archive-latest.asc 2> /dev/null \
+   | gpg --dearmor - \
+   | tee /usr/share/keyrings/kitware-archive-keyring.gpg > /dev/null \
+   && echo "deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ $(lsb_release -cs) main" \
+   | tee /etc/apt/sources.list.d/kitware.list > /dev/null \
+   && apt-get update \
+   && apt-get install -y cmake
+
+# Dotnet
+RUN apt-get update && apt-get install -y dotnet7
+
+# Node
+ARG node_major=18
+RUN mkdir -p /etc/apt/keyrings \
+   && curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key \
+   | gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg \
+   && echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$node_major.x nodistro main" \
+   | tee /etc/apt/sources.list.d/nodesource.list \
+   && apt-get update \
+   && apt-get install -y nodejs
+
+# Emumba (deps)
+RUN apt-get update && apt-get -y install rapidjson-dev
+# Emumba
+COPY emumba /emumba
+RUN dpkg -i /emumba/emumba-deribit-connector-3.3.1-Linux.LICENSE_DISABLED.deb \
+    && rm -r /emumba
+
+# Pcap
+RUN apt-get update && apt-get install -y libpcap0.8-dev
+
+# Set up default executables (update-alternatives)
+RUN \
+   update-alternatives --install /usr/bin/clang clang /usr/bin/clang-$clang_major 100; \
+   update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-$clang_major 100; \
+   update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-$clang_major 100; \
+   update-alternatives --install /usr/bin/clangd clangd /usr/bin/clangd-$clang_major 100; \
+   update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-$gcc_major 100; \
+   update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-$gcc_major 100
+
+# Add compiler symlinks for ccache 
+RUN \
+   ln -s /usr/bin/ccache /usr/local/bin/clang; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang++; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang-$clang_major; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang++-$clang_major; \
+   ln -s /usr/bin/ccache /usr/local/bin/gcc; \
+   ln -s /usr/bin/ccache /usr/local/bin/g++
+
+RUN locale-gen en_US.UTF-8
+
+ARG docker_user="bts"
+ARG docker_uid="1000"
+ARG docker_pass="bts"
+
+RUN \
+   groupadd -g "$docker_uid" "$docker_user" \
+   && useradd \
+   -m \
+   -u "$docker_uid" \
+   -g "$docker_uid" \
+   -G sudo \
+   --password "$(openssl passwd -1 "$docker_pass")" \
+   "$docker_user"

.devcontainer/devcontainer.json

@@ -0,0 +1,48 @@
+{
+  "dockerFile": "Dockerfile",
+  // Creates local dir to mount to HOME in docker 
+  "initializeCommand": "mkdir -p ${localEnv:HOME}/.bts/devcontainer-mounts/${devcontainerId}",
+  "hostRequirements": {
+    "memory": "4gb",
+    "storage": "6gb"
+  },
+  "postCreateCommand": "/home/bts/spark/docker/sparkd/dev/devcontainer_post_create.sh",
+  "containerUser": "bts",
+  "workspaceMount": "source=${localWorkspaceFolder},target=/home/bts/spark,type=bind",
+  "workspaceFolder": "/home/bts/spark",
+  "updateRemoteUserUID": true,
+  "shutdownAction": "none",
+  // Note: If running multiple containers on the same host, each must use a
+  // unique set of ports. Usually we just add 1000 to each port as needed. For
+  // example, if 8000-8003 is taken, go with 9000-9003, then 10000-10003, etc.
+  "runArgs": [
+    "--shm-size",
+    "2gb",
+    "-p",
+    "8000:8000",
+    "-p",
+    "8001:8001",
+    "-p",
+    "8002:8002",
+    "-p",
+    "8003:8003"
+  ],
+  "mounts": [
+    "source=${localEnv:HOME}/.bts/devcontainer-mounts/${devcontainerId},target=/home/bts,type=bind"
+  ],
+  "customizations": {
+    "vscode": {
+      "settings": {
+        "clangd.arguments": [
+          "--compile-commands-dir=${workspaceFolder}/build/clang/debug"
+        ]
+      },
+      "extensions": [
+        "eamodio.gitlens",
+        "llvm-vs-code-extensions.vscode-clangd",
+        "ms-vscode.cmake-tools",
+        "ms-vscode.cpptools"
+      ]
+    }
+  }
+}

.devcontainer/emumba/install_emumba-deribit-connector.sh

@@ -0,0 +1,4 @@
+#!/usr/bin/env bash
+
+this_dir="$(realpath "$(dirname "$(readlink -f "${BASH_SOURCE[0]}")")")"
+sudo dpkg -i "$this_dir/emumba-deribit-connector-3.3.1-Linux.LICENSE_DISABLED.deb"

.gitignore

@@ -47,13 +47,13 @@ trace_data/
 /src/.clang-format
 /src/server/sparkd/cmds/spartan/analysis/.ipynb_checkpoints
 /src/server/sparkd/cmds/spartan/analysis/data
-*.tmp/*
-/.venv*/*
+.tmp/
+.venv*/
 .cache/
 /src/Spark.Admin.WebApp/tsconfig.*.g.json
 /src/Spark.Admin.WebApp/src/bin/
 **/CMakeDeps.cmake
 **/CMakeDeps_win.cmake
-**/devcontainer.json
+.devcontainer/
 *.Generated.cs
 *.lst

.gitmodules

@@ -1,3 +1,6 @@
 [submodule "externals"]
 	path = externals
 	url = git@bitbucket.org:bluetradesys/externals.git
+[submodule "vcpkg"]
+	path = vcpkg
+	url = https://github.com/microsoft/vcpkg.git

CMakePresets.json

@@ -26,6 +26,7 @@
         "CMAKE_CXX_STANDARD": "20",
         "CMAKE_SHARED_LINKER_FLAGS_DEBUG": "/DEBUG",
         "CMAKE_SHARED_LINKER_FLAGS_RELEASE": "/OPT:REF /OPT:ICF /LTCG",
+        "CMAKE_TOOLCHAIN_FILE": "${sourceDir}/vcpkg/scripts/buildsystems/vcpkg.cmake",
         "EXTERNALS_ROOT": "${sourceDir}/externals/windows",
         "CONFIG_DEFAULTS_PATH": "config/profiles/default/*.conf",
         "DOTNET_BINARY_DIR": "${sourceDir}/build/$<CONFIG>/bin/net7.0",
@@ -142,7 +143,7 @@
       "cacheVariables": {
         "CMAKE_C_COMPILER": "gcc",
         "CMAKE_CXX_COMPILER": "g++",
-        "CMAKE_CXX_FLAGS_RELEASE": "-fPIC -Wall -pedantic -Wextra -Werror -Wno-missing-braces -Wno-ignored-qualifiers --std=c++20 -fdiagnostics-color -Wno-stringop-overread -Wno-maybe-uninitialized -fno-omit-frame-pointer -DNDEBUG -O3",
+        "CMAKE_CXX_FLAGS_RELEASE": "-fPIC -Wall -pedantic -Wextra -Werror -Wno-missing-braces -Wno-ignored-qualifiers -Wno-stringop-overflow --std=c++20 -fdiagnostics-color -Wno-stringop-overread -Wno-maybe-uninitialized -fno-omit-frame-pointer -DNDEBUG -O3",
         "CMAKE_INSTALL_PREFIX": "${sourceDir}/install/gcc/release/sparkd"
       }
     },

docker/sparkd/dev/Dockerfile

@@ -48,9 +48,15 @@ RUN apt-get update && apt-get install -y \
 # cmake
 RUN \
     curl -fsSL https://apt.kitware.com/keys/kitware-archive-latest.asc 2> /dev/null \
-    | gpg --dearmor - | tee /etc/apt/trusted.gpg.d/kitware.gpg > /dev/null \
-    && apt-add-repository "deb https://apt.kitware.com/ubuntu/ $(lsb_release -cs) main" \
+    | gpg --dearmor - \
+    | tee /usr/share/keyrings/kitware-archive-keyring.gpg > /dev/null \
+    && echo "deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ $(lsb_release -cs) main" \
+    | tee /etc/apt/sources.list.d/kitware.list > /dev/null \
     && apt-get update \
+    && rm /usr/share/keyrings/kitware-archive-keyring.gpg \
+    && apt-get install -y kitware-archive-keyring \
+    && echo "deb [signed-by=/usr/share/keyrings/kitware-archive-keyring.gpg] https://apt.kitware.com/ubuntu/ $(lsb_release -cs)-rc main" \
+    | tee -a /etc/apt/sources.list.d/kitware.list >/dev/null \
     && apt-get install -y cmake
 
 # node

docker/sparkd/dev/devcontainer.json

@@ -1,6 +1,7 @@
 {
   "image": "bluetradingsystems/sparkd-dev:latest",
-  "initializeCommand": "${localWorkspaceFolder}/docker/sparkd/dev/devcontainer_initialize.sh",
+  // Creates local dir to mount to HOME in docker 
+  "initializeCommand": "mkdir -p ${localEnv:HOME}/.bts/devcontainer-mounts/${devcontainerId}",
   "hostRequirements": {
     "memory": "4gb",
     "storage": "6gb"
@@ -27,6 +28,6 @@
     "8003:8003"
   ],
   "mounts": [
-    "source=${localEnv:HOME}/.sparkd-dev/mounts/sparkd-dev,target=/home/bts,type=bind"
+    "source=${localEnv:HOME}/.bts/devcontainer-mounts/${devcontainerId},target=/home/bts,type=bind"
   ]
 }

docker/sparkd/dev/devcontainer_initialize.sh

@@ -1,3 +0,0 @@
-#!/usr/bin/env bash
-
-mkdir -p "$HOME/.sparkd-dev/mounts/sparkd-dev"

src/DataStreamSuite/ArithmeticExpressions/ArithmeticExpressionTokens.lex

@@ -14,7 +14,7 @@ ParenthesisClose   \)
 Add                \+
 Subtract           \-
 Multiply           \*
-Divide             \\
+Divide             /
 Equals             =
 Comma              ,
 

src/DataStreamSuite/ArithmeticExpressions/ArithmeticExpressions.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Google.Protobuf" Version="3.24.3" />
-    <PackageReference Include="YaccLexTools" Version="1.2.0" />
+    <PackageReference Include="YaccLexTools" Version="1.2.2" />
   </ItemGroup>
 
   <ItemGroup>

src/DataStreamSuite/BooleanExpressions/Arguments/ArgumentComparer.cs

@@ -2,6 +2,8 @@ namespace Bts.BooleanExpressions.Arguments;
 
 using bts;
 
+using Spark.Core.Collections;
+
 static class ArgumentComparer {
    public static int Compare(
       IArgument value1, IArgument value2, IDictionary<string,object?> env) {
@@ -14,7 +16,10 @@ static class ArgumentComparer {
       var cmp1 = value1.Cast<IComparable>();
       var cmp2 = value2.Cast<IComparable>();
       try {
-         return cmp1.GetValue(env).CompareTo(cmp2.GetValue(env));
+         var v1 = cmp1.GetValue(env);
+         var v2 = cmp2.GetValue(env);
+         return v1.GetType().IsNumeric() ?
+            new NumericComparer().Compare(v1, v2) : v1.CompareTo(v2);
       } catch (Exception ex) {
          Log.Ui.error($"Comparison failed: {ex}");
          throw;

src/DataStreamSuite/BooleanExpressions/BooleanExpressionGrammar.y

@@ -44,7 +44,7 @@
 %%
 
 BoundExpression : Definitions Expression { $$ = new($2, $1); }
-   | Expression;
+   | Expression { $$ = new($1, ImmutableList<Definition>.Empty); };
 
 Definitions :
    Definition { $$ = ImmutableList<Definition>.Empty.Add($1); }
@@ -57,46 +57,70 @@ Definition :
 
 Expression :
    Expression OR Expression {
-      $$ = new(env => $1.Evaluate(env) || $3.Evaluate(env));
+      var left = $1;
+      var right = $3;
+      $$ = new(env => left.Evaluate(env) || right.Evaluate(env));
    }
    | Expression AND Expression {
-      $$ = new(env => $1.Evaluate(env) && $3.Evaluate(env));
+      var left = $1;
+      var right = $3;
+      $$ = new(env => left.Evaluate(env) && right.Evaluate(env));
    }
    | Expression XOR Expression {
-      $$ = new(env => $1.Evaluate(env) != $3.Evaluate(env));
+      var left = $1;
+      var right = $3;
+      $$ = new(env => left.Evaluate(env) != right.Evaluate(env));
    }
    | NOT Expression {
-      $$ = new(env => !$2.Evaluate(env));
+      var exp = $2;
+      $$ = new(env => !exp.Evaluate(env));
    }
    | PARENTHESIS_OPEN Expression PARENTHESIS_CLOSE {
       $$ = $2; 
    }
    | Argument GREATER Argument {
-      $$ = new(env => Arguments.ArgumentComparer.Compare($1, $3, env) > 0);
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentComparer.Compare(left, right, env) > 0);
    }
    | Argument GREATER_EQUAL Argument {
-      $$ = new(env => Arguments.ArgumentComparer.Compare($1, $3, env) >= 0);
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentComparer.Compare(left, right, env) >= 0);
    }
    | Argument EQUAL Argument {
-      $$ = new(env => Arguments.ArgumentComparer.Compare($1, $3, env) == 0);
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentComparer.Compare(left, right, env) == 0);
    }
    | Argument LESS_EQUAL Argument {
-      $$ = new(env => Arguments.ArgumentComparer.Compare($1, $3, env) <= 0);
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentComparer.Compare(left, right, env) <= 0);
    }
    | Argument LESS Argument {
-      $$ = new(env => Arguments.ArgumentComparer.Compare($1, $3, env) < 0);
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentComparer.Compare(left, right, env) < 0);
    }
    | Argument DIFFERENT Argument {
-      $$ = new(env => Arguments.ArgumentComparer.Compare($1, $3, env) != 0);
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentComparer.Compare(left, right, env) != 0);
    }
    | Argument DIFFERENT2 Argument {
-      $$ = new(env => Arguments.ArgumentComparer.Compare($1, $3, env) != 0);
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentComparer.Compare(left, right, env) != 0);
    }
    | Argument MATCHES Argument {
-      $$ = new(env => Arguments.ArgumentMatcher.Match($1, $3, env));
+      var left = $1;
+      var right = $3;
+      $$ = new(env => Arguments.ArgumentMatcher.Match(left, right, env));
    }
    | Argument {
-      $$ = new(env => (bool)$1.GetValue(env));
+      var arg = $1;
+      $$ = new(env => (bool)arg.GetValue(env));
    }
    ;
 

src/DataStreamSuite/Bts.ColumnExpressions/Bts.ColumnExpressions.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="YaccLexTools" Version="1.2.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\DataStreamCore\DataStreamCore.csproj" />
+    <ProjectReference Include="..\ExpressionCore\ExpressionCore.csproj" />
+    <ProjectReference Include="..\..\client\spark_core\spark_core.csproj" />
+  </ItemGroup>
+
+  <ItemGroup Label="ColumnExpression">
+    <Scanner Include="ColumnExpressionTokens.lex" />
+    <Parser Include="ColumnExpressionGrammar.y" />
+  </ItemGroup>
+
+</Project>

src/DataStreamSuite/Bts.ColumnExpressions/ColumnExpression.cs

@@ -0,0 +1,62 @@
+namespace Bts.ColumnExpressions;
+
+public class ColumnExpression {
+   public ColumnExpression(string name, Type? type = null, object? value = null) {
+      Name = name;
+      Type = type
+         ?? value?.GetType()
+         ?? throw new ArgumentException(
+            "Type must be specified explicitly when value is null", nameof(type));
+      Value = value
+         ?? DBNull.Value;
+   }
+
+   public string Name { get; }
+
+   public Type Type { get; }
+
+   public object Value { get; }
+
+   public static ColumnExpression Create<T>(string name, T value, Type? type = null) {
+      // Try to convert value to 'type' to verify they are compatible
+      // Note: Can't use `System.Type.IsAssignableFrom` because it doesn't
+      // account for implicit conversions (e.g., int -> long), just inheritance.
+      if (type is not null && !ConvertUtils.try_convert(type, value, out _)) {
+         throw new ArgumentException(
+            $"Type '{type}' is not assignable from value type '{value?.GetType()}'");
+      }
+      return new(name, type ?? typeof(T), value);
+   }
+
+   internal static Type ParseType(string typeId) {
+      return Candidates().ExceptNull().FirstOrDefault() ??
+         throw new ArgumentException($"Failed to parse Type from '{typeId}'", nameof(typeId));
+
+      IEnumerable<Type?> Candidates() {
+         if (typeId.Length == 0) {
+            yield break;
+         }
+         yield return Type.GetType(typeId);
+         yield return Type.GetType($"System.{typeId}");
+         if (typeId.Length > 1) {
+            yield return Type.GetType($"System.{char.ToUpper(typeId[0]) + typeId[1..]}");
+         }
+         yield return typeId.ToLower() switch {
+            "float64" or "double" or "real64" or "number" => typeof(double),
+            "float32" or "single" or "real32" or "real" or "float" => typeof(float),
+            "int16" or "short" or "integer16" or "signed16" => typeof(short),
+            "int32" or "int" or "integer" or "integer32" or "signed" => typeof(int),
+            "int64" or "long" or "integer64" or "signed64" => typeof(long),
+            "uint16" or "ushort" or "unsigned16" => typeof(ushort),
+            "uint32" or "uint" or "unsigned" => typeof(uint),
+            "uint64" or "ulong" or "unsigned64" => typeof(ulong),
+            "char" => typeof(char),
+            "byte" or "uint8" => typeof(byte),
+            "bool" or "boolean" => typeof(bool),
+            "string" or "text" => typeof(string),
+            "date" or "datetime" => typeof(DateTime),
+            _ => null
+         };
+      }
+   }
+}

src/DataStreamSuite/Bts.ColumnExpressions/ColumnExpressionGrammar.y

@@ -0,0 +1,49 @@
+%namespace Bts.ColumnExpressions
+%partial
+%visibility internal
+%tokentype ColumnExpressionToken
+%parsertype ColumnExpressionParser
+
+%union {
+   public int Integer;
+   public double Real;
+   public bool Boolean;
+   public string String;
+   public string Identifier;
+   public string TypeId;
+   public DateTime DateTime;
+   public Tuple<string, Type> ColumnDefinition;
+   public ColumnExpression ColumnExpression;
+   public ImmutableList<ColumnExpression> ColumnExpressions;
+}
+
+%token BOOLEAN_CONSTANT, INTEGER_CONSTANT, REAL_CONSTANT, DATE_TIME_CONSTANT, STRING_CONSTANT
+%token IDENTIFIER, EQUALS, TYPE_ID, OF_TYPE
+
+%nonassoc EQUALS
+
+%type <ColumnDefinition> ColumnDefinition
+%type <ColumnExpression> ColumnExpression
+%type <ColumnExpressions> ColumnExpressions
+
+%%
+
+ColumnExpressions :
+   ColumnExpression { $$ = ImmutableList.CreateRange(new[] { $1 }); }
+   | ColumnExpressions ColumnExpression { $$ = $1.Add($2); }
+   ;
+
+ColumnExpression :
+   ColumnDefinition EQUALS INTEGER_CONSTANT { $$ = ColumnExpression.Create($1.Item1, $3.Integer, $1.Item2); }
+   | ColumnDefinition EQUALS REAL_CONSTANT { $$ = ColumnExpression.Create($1.Item1, $3.Real, $1.Item2); }
+   | ColumnDefinition EQUALS DATE_TIME_CONSTANT { $$ = ColumnExpression.Create($1.Item1, $3.DateTime, $1.Item2); }
+   | ColumnDefinition EQUALS BOOLEAN_CONSTANT { $$ = ColumnExpression.Create($1.Item1, $3.Boolean, $1.Item2); }
+   | ColumnDefinition EQUALS STRING_CONSTANT { $$ = ColumnExpression.Create($1.Item1, $3.String, $1.Item2); }
+   | ColumnDefinition { $$ = new($1.Item1, $1.Item2); }
+   ;
+
+ColumnDefinition :
+   IDENTIFIER { $$ = new($1.Identifier, null); }
+   | IDENTIFIER OF_TYPE IDENTIFIER { $$ = new($1.Identifier, ColumnExpression.ParseType($3.Identifier)); }
+   | IDENTIFIER OF_TYPE TYPE_ID { $$ = new($1.Identifier, ColumnExpression.ParseType($3.TypeId)); }
+   ; 

src/DataStreamSuite/Bts.ColumnExpressions/ColumnExpressionInterpreter.cs

@@ -0,0 +1,18 @@
+namespace Bts.ColumnExpressions;
+
+using System.IO;
+using System.Text;
+
+public class ColumnExpressionInterpreter {
+   public static IList<ColumnExpression> Evaluate(Stream stream) {
+      var parser = new ColumnExpressionParser();
+      var res = parser.Parse(stream);
+      return res?.ColumnExpressions ?? ImmutableList<ColumnExpression>.Empty.Add(
+         res?.ColumnExpression ?? throw new Exception("Failed to parse column(s) expression"));
+   }
+
+   public static IList<ColumnExpression> Evaluate(string str) {
+      using var ms = new MemoryStream(Encoding.Default.GetBytes(str));
+      return Evaluate(ms);
+   }
+}

src/DataStreamSuite/Bts.ColumnExpressions/ColumnExpressionParser.cs

@@ -0,0 +1,18 @@
+namespace Bts.ColumnExpressions;
+
+using System.Text;
+
+partial class ColumnExpressionParser {
+   public ColumnExpressionParser() : base(null) { }
+
+   public ValueType? Parse(string s) {
+      using var ms = new MemoryStream(Encoding.Default.GetBytes(s));
+      return Parse(ms);
+   }
+
+   public ValueType? Parse(Stream stream) {
+      Scanner = new ColumnExpressionScanner(stream);
+      Parse();
+      return CurrentSemanticValue;
+   }
+}

src/DataStreamSuite/Bts.ColumnExpressions/ColumnExpressionScanner.cs

@@ -0,0 +1,9 @@
+namespace Bts.ColumnExpressions;
+
+partial class ColumnExpressionScanner {
+   public override void yyerror(string format, params object[] args) {
+      base.yyerror(format, args);
+      Console.WriteLine(format, args);
+      Console.WriteLine();
+   }
+}

src/DataStreamSuite/Bts.ColumnExpressions/ColumnExpressionTokens.lex

@@ -0,0 +1,85 @@
+%namespace Bts.ColumnExpressions
+%scannertype ColumnExpressionScanner
+%visibility internal
+%tokentype ColumnExpressionToken
+
+%option stack, minimize, parser, verbose, persistbuffer, noembedbuffers 
+
+/* Literal Constants */
+Letter                   [a-zA-Z]
+BooleanConstant          true|false
+StringConstant           '([^\'\\]*|\\.)*'
+DateTimeConstant         ([1-9]|'10'|'11'|'12')\/([1-9]|([1-2][0-9])|'30'|'31')\/[0-9][0-9][0-9]*
+IntegerConstant          -?[0-9]+
+NullConstant             'null'
+RealConstant             -?[0-9]+\.[0-9]+
+
+/* Relational Operators */
+Equals                   =
+OfType                   /
+
+Identifier               {Letter}({Letter}*[0-9]*_*)*
+NamespacePrefix          {Identifier}\.
+TypeId                   {NamespacePrefix}*{Identifier}
+
+/* Utility Tokens */
+OpenParenthesis          \(
+CloseParenthesis         \)
+Comma                    ,
+QuoteOpen                \[
+QuoteClose               \]
+
+/* Comments */
+LineComment \/\/[^\n\r]*(\n|\r|\r\n)
+
+%%
+
+{Equals} {
+   return (int)ColumnExpressionToken.EQUALS;
+}
+
+{OfType} {
+   return (int)ColumnExpressionToken.OF_TYPE;
+}
+
+{StringConstant} {
+   yylval.String = yytext.Substring(1, yytext.Length - 2).Replace(@"\'","'");
+   return (int)ColumnExpressionToken.STRING_CONSTANT;
+}
+
+{BooleanConstant} {
+   yylval.Boolean = yytext.ToLower() switch {
+      "true" => true,
+      "false" => false,
+      _ => throw new Exception(
+         string.Format("Expected yytext to be 'true' or 'false' (actually '{0}')", yytext))
+   };
+   return (int)ColumnExpressionToken.BOOLEAN_CONSTANT;
+}
+
+{DateTimeConstant} {
+   yylval.DateTime = DateTime.Parse(yytext);
+   return (int)ColumnExpressionToken.DATE_TIME_CONSTANT;
+}
+
+{IntegerConstant} {
+   yylval.Integer = int.Parse(yytext);
+   return (int)ColumnExpressionToken.INTEGER_CONSTANT;
+}
+
+{RealConstant} {
+   yylval.Real = double.Parse(yytext);
+   return (int)ColumnExpressionToken.REAL_CONSTANT;
+}
+
+{Identifier} {
+   yylval.Identifier = yytext;
+   return (int)ColumnExpressionToken.IDENTIFIER;
+}
+
+{TypeId} {
+   yylval.TypeId = yytext;   
+   return (int)ColumnExpressionToken.TYPE_ID;
+}
+
+%%

src/DataStreamSuite/Bts.ColumnExpressions/GplexBuffers.cs

@@ -0,0 +1,720 @@
+// ==============================================================
+// <auto-generated>
+// This code automatically produced from an embedded resource.
+// Do not edit this file, or it will become incompatible with 
+// the specification from which it was generated.
+// </auto-generated>
+// ==============================================================
+
+using System;
+using System.IO;
+using System.Text;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.Serialization;
+using System.Globalization;
+
+namespace QUT.GplexBuffers
+{
+// Code copied from GPLEX embedded resource
+    [Serializable]
+    internal class BufferException : Exception
+    {
+        public BufferException() { }
+        public BufferException(string message) : base(message) { }
+        public BufferException(string message, Exception innerException)
+            : base(message, innerException) { }
+        protected BufferException(SerializationInfo info, StreamingContext context)
+            : base(info, context) { }
+    }
+
+    internal abstract class ScanBuff
+    {
+        private string fileNm;
+
+        public const int EndOfFile = -1;
+        public const int UnicodeReplacementChar = 0xFFFD;
+
+        public bool IsFile { get { return (fileNm != null); } }
+        public string FileName { get { return fileNm; } set { fileNm = value; } }
+
+        public abstract int Pos { get; set; }
+        public abstract int Read();
+        public virtual void Mark() { }
+
+        public abstract string GetString(int begin, int limit);
+
+        public static ScanBuff GetBuffer(string source)
+        {
+            return new StringBuffer(source);
+        }
+
+        public static ScanBuff GetBuffer(IList<string> source)
+        {
+            return new LineBuffer(source);
+        }
+
+#if (!NOFILES)
+        public static ScanBuff GetBuffer(Stream source)
+        {
+            return new BuildBuffer(source);
+        }
+
+#if (!BYTEMODE)
+        public static ScanBuff GetBuffer(Stream source, int fallbackCodePage)
+        {
+            return new BuildBuffer(source, fallbackCodePage);
+        }
+#endif // !BYTEMODE
+#endif // !NOFILES
+    }
+
+    #region Buffer classes
+
+    // ==============================================================
+    // =====  Definitions for various ScanBuff derived classes   ====
+    // ==============================================================
+    // ===============         String input          ================
+    // ==============================================================
+
+    /// <summary>
+    /// This class reads characters from a single string as
+    /// required, for example, by Visual Studio language services
+    /// </summary>
+    sealed class StringBuffer : ScanBuff
+    {
+        string str;        // input buffer
+        int bPos;          // current position in buffer
+        int sLen;
+
+        public StringBuffer(string source)
+        {
+            this.str = source;
+            this.sLen = source.Length;
+            this.FileName = null;
+        }
+
+        public override int Read()
+        {
+            if (bPos < sLen) return str[bPos++];
+            else if (bPos == sLen) { bPos++; return '\n'; }   // one strike, see new line
+            else { bPos++; return EndOfFile; }                // two strikes and you're out!
+        }
+
+        public override string GetString(int begin, int limit)
+        {
+            //  "limit" can be greater than sLen with the BABEL
+            //  option set.  Read returns a "virtual" EOL if
+            //  an attempt is made to read past the end of the
+            //  string buffer.  Without the guard any attempt 
+            //  to fetch yytext for a token that includes the 
+            //  EOL will throw an index exception.
+            if (limit > sLen) limit = sLen;
+            if (limit <= begin) return "";
+            else return str.Substring(begin, limit - begin);
+        }
+
+        public override int Pos
+        {
+            get { return bPos; }
+            set { bPos = value; }
+        }
+
+        public override string ToString() { return "StringBuffer"; }
+    }
+
+    // ==============================================================
+    //  The LineBuff class contributed by Nigel Horspool, 
+    //  nigelh@cs.uvic.cs
+    // ==============================================================
+
+    sealed class LineBuffer : ScanBuff
+    {
+        IList<string> line;    // list of source lines from a file
+        int numLines;          // number of strings in line list
+        string curLine;        // current line in that list
+        int cLine;             // index of current line in the list
+        int curLen;            // length of current line
+        int curLineStart;      // position of line start in whole file
+        int curLineEnd;        // position of line end in whole file
+        int maxPos;            // max position ever visited in whole file
+        int cPos;              // ordinal number of code in source
+
+        // Constructed from a list of strings, one per source line.
+        // The lines have had trailing '\n' characters removed.
+        public LineBuffer(IList<string> lineList)
+        {
+            line = lineList;
+            numLines = line.Count;
+            cPos = curLineStart = 0;
+            curLine = (numLines > 0 ? line[0] : "");
+            maxPos = curLineEnd = curLen = curLine.Length;
+            cLine = 1;
+            FileName = null;
+        }
+
+        public override int Read()
+        {
+            if (cPos < curLineEnd)
+                return curLine[cPos++ - curLineStart];
+            if (cPos++ == curLineEnd)
+                return '\n';
+            if (cLine >= numLines)
+                return EndOfFile;
+            curLine = line[cLine];
+            curLen = curLine.Length;
+            curLineStart = curLineEnd + 1;
+            curLineEnd = curLineStart + curLen;
+            if (curLineEnd > maxPos)
+                maxPos = curLineEnd;
+            cLine++;
+            return curLen > 0 ? curLine[0] : '\n';
+        }
+
+        // To speed up searches for the line containing a position
+        private int cachedPosition;
+        private int cachedIxdex;
+        private int cachedLineStart;
+
+        // Given a position pos within the entire source, the results are
+        //   ix     -- the index of the containing line
+        //   lstart -- the position of the first character on that line
+        private void findIndex(int pos, out int ix, out int lstart)
+        {
+            if (pos >= cachedPosition)
+            {
+                ix = cachedIxdex; lstart = cachedLineStart;
+            }
+            else
+            {
+                ix = lstart = 0;
+            }
+            while (ix < numLines)
+            {
+                int len = line[ix].Length + 1;
+                if (pos < lstart + len) break;
+                lstart += len;
+                ix++;
+            }
+            cachedPosition = pos;
+            cachedIxdex = ix;
+            cachedLineStart = lstart;
+        }
+
+        public override string GetString(int begin, int limit)
+        {
+            if (begin >= maxPos || limit <= begin) return "";
+            int endIx, begIx, endLineStart, begLineStart;
+            findIndex(begin, out begIx, out begLineStart);
+            int begCol = begin - begLineStart;
+            findIndex(limit, out endIx, out endLineStart);
+            int endCol = limit - endLineStart;
+            string s = line[begIx];
+            if (begIx == endIx)
+            {
+                // the usual case, substring all on one line
+                return (endCol <= s.Length) ?
+                    s.Substring(begCol, endCol - begCol)
+                    : s.Substring(begCol) + "\n";
+            }
+            // the string spans multiple lines, yuk!
+            StringBuilder sb = new StringBuilder();
+            if (begCol < s.Length)
+                sb.Append(s.Substring(begCol));
+            for (; ; )
+            {
+                sb.Append("\n");
+                s = line[++begIx];
+                if (begIx >= endIx) break;
+                sb.Append(s);
+            }
+            if (endCol <= s.Length)
+            {
+                sb.Append(s.Substring(0, endCol));
+            }
+            else
+            {
+                sb.Append(s);
+                sb.Append("\n");
+            }
+            return sb.ToString();
+        }
+
+        public override int Pos
+        {
+            get { return cPos; }
+            set
+            {
+                cPos = value;
+                findIndex(cPos, out cLine, out curLineStart);
+                // cLine should be the *next* line after curLine.
+                curLine = (cLine < numLines ? line[cLine++] : "");
+                curLineEnd = curLineStart + curLine.Length;
+            }
+        }
+
+        public override string ToString() { return "LineBuffer"; }
+    }
+
+#if (!NOFILES)
+    // ==============================================================
+    // =====     class BuildBuff : for unicode text files    ========
+    // ==============================================================
+
+    class BuildBuffer : ScanBuff
+    {
+        // Double buffer for char stream.
+        class BufferElement
+        {
+            StringBuilder bldr = new StringBuilder();
+            StringBuilder next = new StringBuilder();
+            int minIx;
+            int maxIx;
+            int brkIx;
+            bool appendToNext;
+
+            internal BufferElement() { }
+
+            internal int MaxIndex { get { return maxIx; } }
+            // internal int MinIndex { get { return minIx; } }
+
+            internal char this[int index]
+            {
+                get
+                {
+                    if (index < minIx || index >= maxIx)
+                        throw new BufferException("Index was outside data buffer");
+                    else if (index < brkIx)
+                        return bldr[index - minIx];
+                    else
+                        return next[index - brkIx];
+                }
+            }
+
+            internal void Append(char[] block, int count)
+            {
+                maxIx += count;
+                if (appendToNext)
+                    this.next.Append(block, 0, count);
+                else
+                {
+                    this.bldr.Append(block, 0, count);
+                    brkIx = maxIx;
+                    appendToNext = true;
+                }
+            }
+
+            internal string GetString(int start, int limit)
+            {
+                if (limit <= start)
+                    return "";
+                if (start >= minIx && limit <= maxIx)
+                    if (limit < brkIx) // String entirely in bldr builder
+                        return bldr.ToString(start - minIx, limit - start);
+                    else if (start >= brkIx) // String entirely in next builder
+                        return next.ToString(start - brkIx, limit - start);
+                    else // Must do a string-concatenation
+                        return
+                            bldr.ToString(start - minIx, brkIx - start) +
+                            next.ToString(0, limit - brkIx);
+                else
+                    throw new BufferException("String was outside data buffer");
+            }
+
+            internal void Mark(int limit)
+            {
+                if (limit > brkIx + 16) // Rotate blocks
+                {
+                    StringBuilder temp = bldr;
+                    bldr = next;
+                    next = temp;
+                    next.Length = 0;
+                    minIx = brkIx;
+                    brkIx = maxIx;
+                }
+            }
+        }
+
+        BufferElement data = new BufferElement();
+
+        int bPos;            // Postion index in the StringBuilder
+        BlockReader NextBlk; // Delegate that serves char-arrays;
+
+        private string EncodingName
+        {
+            get
+            {
+                StreamReader rdr = NextBlk.Target as StreamReader;
+                return (rdr == null ? "raw-bytes" : rdr.CurrentEncoding.BodyName);
+            }
+        }
+
+        public BuildBuffer(Stream stream)
+        {
+            FileStream fStrm = (stream as FileStream);
+            if (fStrm != null) FileName = fStrm.Name;
+            NextBlk = BlockReaderFactory.Raw(stream);
+        }
+
+#if (!BYTEMODE)
+        public BuildBuffer(Stream stream, int fallbackCodePage)
+        {
+            FileStream fStrm = (stream as FileStream);
+            if (fStrm != null) FileName = fStrm.Name;
+            NextBlk = BlockReaderFactory.Get(stream, fallbackCodePage);
+        }
+#endif
+
+        /// <summary>
+        /// Marks a conservative lower bound for the buffer,
+        /// allowing space to be reclaimed.  If an application 
+        /// needs to call GetString at arbitrary past locations 
+        /// in the input stream, Mark() is not called.
+        /// </summary>
+        public override void Mark() { data.Mark(bPos - 2); }
+
+        public override int Pos
+        {
+            get { return bPos; }
+            set { bPos = value; }
+        }
+
+
+        /// <summary>
+        /// Read returns the ordinal number of the next char, or 
+        /// EOF (-1) for an end of stream.  Note that the next
+        /// code point may require *two* calls of Read().
+        /// </summary>
+        /// <returns></returns>
+        public override int Read()
+        {
+            //
+            //  Characters at positions 
+            //  [data.offset, data.offset + data.bldr.Length)
+            //  are available in data.bldr.
+            //
+            if (bPos < data.MaxIndex)
+            {
+                // ch0 cannot be EOF
+                return (int)data[bPos++];
+            }
+            else // Read from underlying stream
+            {
+                // Experimental code, blocks of page size
+                char[] chrs = new char[4096];
+                int count = NextBlk(chrs, 0, 4096);
+                if (count == 0)
+                    return EndOfFile;
+                else
+                {
+                    data.Append(chrs, count);
+                    return (int)data[bPos++];
+                }
+            }
+        }
+
+        public override string GetString(int begin, int limit)
+        {
+            return data.GetString(begin, limit);
+        }
+
+        public override string ToString()
+        {
+            return "StringBuilder buffer, encoding: " + this.EncodingName;
+        }
+    }
+
+    // =============== End ScanBuff-derived classes ==================
+
+    internal delegate int BlockReader(char[] block, int index, int number);
+
+    // A delegate factory, serving up a delegate that
+    // reads a block of characters from the underlying
+    // encoded stream, via a StreamReader object.
+    //
+    internal static class BlockReaderFactory
+    {
+        public static BlockReader Raw(Stream stream)
+        {
+            return delegate(char[] block, int index, int number)
+            {
+                byte[] b = new byte[number];
+                int count = stream.Read(b, 0, number);
+                int i = 0;
+                int j = index;
+                for (; i < count; i++, j++)
+                    block[j] = (char)b[i];
+                return count;
+            };
+        }
+
+#if (!BYTEMODE)
+        public static BlockReader Get(Stream stream, int fallbackCodePage)
+        {
+            Encoding encoding;
+            int preamble = Preamble(stream);
+
+            if (preamble != 0)  // There is a valid BOM here!
+                encoding = Encoding.GetEncoding(preamble);
+            else if (fallbackCodePage == -1) // Fallback is "raw" bytes
+                return Raw(stream);
+            else if (fallbackCodePage != -2) // Anything but "guess"
+                encoding = Encoding.GetEncoding(fallbackCodePage);
+            else // This is the "guess" option
+            {
+                int guess = new Guesser(stream).GuessCodePage();
+                stream.Seek(0, SeekOrigin.Begin);
+                if (guess == -1) // ==> this is a 7-bit file
+                    encoding = Encoding.ASCII;
+                else if (guess == 65001)
+                    encoding = Encoding.UTF8;
+                else             // ==> use the machine default
+                    encoding = Encoding.Default;
+            }
+            StreamReader reader = new StreamReader(stream, encoding);
+            return reader.Read;
+        }
+
+        static int Preamble(Stream stream)
+        {
+            int b0 = stream.ReadByte();
+            int b1 = stream.ReadByte();
+
+            if (b0 == 0xfe && b1 == 0xff)
+                return 1201; // UTF16BE
+            if (b0 == 0xff && b1 == 0xfe)
+                return 1200; // UTF16LE
+
+            int b2 = stream.ReadByte();
+            if (b0 == 0xef && b1 == 0xbb && b2 == 0xbf)
+                return 65001; // UTF8
+            //
+            // There is no unicode preamble, so we
+            // return denoter for the machine default.
+            //
+            stream.Seek(0, SeekOrigin.Begin);
+            return 0;
+        }
+#endif // !BYTEMODE
+    }
+#endif // !NOFILES
+    #endregion Buffer classes
+
+    // ==============================================================
+    // ============      class CodePageHandling         =============
+    // ==============================================================
+#if (!NOFILES)
+    public static class CodePageHandling
+    {
+        public static int GetCodePage(string option)
+        {
+            string command = option.ToUpperInvariant();
+            if (command.StartsWith("CodePage:", StringComparison.OrdinalIgnoreCase))
+                command = command.Substring(9);
+            try
+            {
+                if (command.Equals("RAW"))
+                    return -1;
+                else if (command.Equals("GUESS"))
+                    return -2;
+                else if (command.Equals("DEFAULT"))
+                    return 0;
+                else if (char.IsDigit(command[0]))
+                    return int.Parse(command, CultureInfo.InvariantCulture);
+                else
+                {
+                    Encoding enc = Encoding.GetEncoding(command);
+                    return enc.CodePage;
+                }
+            }
+            catch (FormatException)
+            {
+                Console.Error.WriteLine(
+                    "Invalid format \"{0}\", using machine default", option);
+            }
+            catch (ArgumentException)
+            {
+                Console.Error.WriteLine(
+                    "Unknown code page \"{0}\", using machine default", option);
+            }
+            return 0;
+        }
+    }
+#region guesser
+#if (!BYTEMODE)
+    // ==============================================================
+    // ============          Encoding Guesser           =============
+    // ==============================================================
+
+    /// <summary>
+    /// This class provides a simple finite state automaton that
+    /// scans the file looking for (1) valid UTF-8 byte patterns,
+    /// (2) bytes >= 0x80 which are not part of a UTF-8 sequence.
+    /// The method then guesses whether it is UTF-8 or maybe some 
+    /// local machine default encoding.  This works well for the
+    /// various Latin encodings.
+    /// </summary>
+    internal class Guesser
+    {
+        ScanBuff buffer;
+
+        public int GuessCodePage() { return Scan(); }
+
+        const int maxAccept = 10;
+        const int initial = 0;
+        const int eofNum = 0;
+        const int goStart = -1;
+        const int INITIAL = 0;
+        const int EndToken = 0;
+
+        #region user code
+        /* 
+         *  Reads the bytes of a file to determine if it is 
+         *  UTF-8 or a single-byte code page file.
+         */
+        public long utfX;
+        public long uppr;
+        #endregion user code
+
+        int state;
+        int currentStart = startState[0];
+        int code;
+
+        #region ScannerTables
+        static int[] startState = new int[] { 11, 0 };
+
+        #region CharacterMap
+        static sbyte[] map = new sbyte[256] {
+/*     '\0' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*   '\x10' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*   '\x20' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      '0' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      '@' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      'P' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      '`' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      'p' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*   '\x80' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\x90' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\xA0' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\xB0' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\xC0' */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
+/*   '\xD0' */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
+/*   '\xE0' */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
+/*   '\xF0' */ 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5 };
+        #endregion
+
+        static sbyte[][] nextState = new sbyte[][] {
+            new sbyte[] {0, 0, 0, 0, 0, 0},
+            new sbyte[] {-1, -1, 10, -1, -1, -1},
+            new sbyte[] {-1, -1, -1, -1, -1, -1},
+            new sbyte[] {-1, -1, 8, -1, -1, -1},
+            new sbyte[] {-1, -1, 5, -1, -1, -1},
+            new sbyte[] {-1, -1, 6, -1, -1, -1},
+            new sbyte[] {-1, -1, 7, -1, -1, -1},
+            null,
+            new sbyte[] {-1, -1, 9, -1, -1, -1},
+            null,
+            null,
+            new sbyte[] {-1, 1, 2, 3, 4, 2}
+        };
+
+
+        [SuppressMessage("Microsoft.Performance", "CA1810:InitializeReferenceTypeStaticFieldsInline")]
+        // Reason for suppression: cannot have self-reference in array initializer.
+        static Guesser()
+        {
+            nextState[7] = nextState[2];
+            nextState[9] = nextState[2];
+            nextState[10] = nextState[2];
+        }
+
+        int NextState()
+        {
+            if (code == ScanBuff.EndOfFile)
+                return eofNum;
+            else
+                return nextState[state][map[code]];
+        }
+        #endregion
+
+        public Guesser(System.IO.Stream file) { SetSource(file); }
+
+        public void SetSource(System.IO.Stream source)
+        {
+            this.buffer = new BuildBuffer(source);
+            code = buffer.Read();
+        }
+
+        int Scan()
+        {
+            for (; ; )
+            {
+                int next;
+                state = currentStart;
+                while ((next = NextState()) == goStart)
+                    code = buffer.Read();
+
+                state = next;
+                code = buffer.Read();
+
+                while ((next = NextState()) > eofNum)
+                {
+                    state = next;
+                    code = buffer.Read();
+                }
+                if (state <= maxAccept)
+                {
+                    #region ActionSwitch
+#pragma warning disable 162
+                    switch (state)
+                    {
+                        case eofNum:
+                            switch (currentStart)
+                            {
+                                case 11:
+                                    if (utfX == 0 && uppr == 0) return -1; /* raw ascii */
+                                    else if (uppr * 10 > utfX) return 0;   /* default code page */
+                                    else return 65001;                     /* UTF-8 encoding */
+                                    break;
+                            }
+                            return EndToken;
+                        case 1: // Recognized '{Upper128}',	Shortest string "\xC0"
+                        case 2: // Recognized '{Upper128}',	Shortest string "\x80"
+                        case 3: // Recognized '{Upper128}',	Shortest string "\xE0"
+                        case 4: // Recognized '{Upper128}',	Shortest string "\xF0"
+                            uppr++;
+                            break;
+                        case 5: // Recognized '{Utf8pfx4}{Utf8cont}',	Shortest string "\xF0\x80"
+                            uppr += 2;
+                            break;
+                        case 6: // Recognized '{Utf8pfx4}{Utf8cont}{2}',	Shortest string "\xF0\x80\x80"
+                            uppr += 3;
+                            break;
+                        case 7: // Recognized '{Utf8pfx4}{Utf8cont}{3}',	Shortest string "\xF0\x80\x80\x80"
+                            utfX += 3;
+                            break;
+                        case 8: // Recognized '{Utf8pfx3}{Utf8cont}',	Shortest string "\xE0\x80"
+                            uppr += 2;
+                            break;
+                        case 9: // Recognized '{Utf8pfx3}{Utf8cont}{2}',	Shortest string "\xE0\x80\x80"
+                            utfX += 2;
+                            break;
+                        case 10: // Recognized '{Utf8pfx2}{Utf8cont}',	Shortest string "\xC0\x80"
+                            utfX++;
+                            break;
+                        default:
+                            break;
+                    }
+#pragma warning restore 162
+                    #endregion
+                }
+            }
+        }
+    } // end class Guesser
+    
+#endif // !BYTEMODE
+#endregion
+#endif // !NOFILES
+
+// End of code copied from embedded resource
+}

src/DataStreamSuite/Bts.ColumnExpressions/ShiftReduceParserCode.cs

@@ -0,0 +1,884 @@
+// ==============================================================
+// <auto-generated>
+// This code automatically produced from an embedded resource.
+// Do not edit this file, or it will become incompatible with 
+// the specification from which it was generated.
+// </auto-generated>
+// ==============================================================
+
+// Gardens Point Parser Generator
+// Copyright (c) Wayne Kelly, QUT 2005-2010
+// (see accompanying GPPGcopyright.rtf)
+
+using System;
+using System.Text;
+using System.Globalization;
+using System.Collections.Generic;
+using System.Runtime.Serialization;
+using System.Diagnostics.CodeAnalysis;
+
+namespace QUT.Gppg {
+    /// <summary>
+    /// Abstract class for GPPG shift-reduce parsers.
+    /// Parsers generated by GPPG derive from this base
+    /// class, overriding the abstract Initialize() and
+    /// DoAction() methods.
+    /// </summary>
+    /// <typeparam name="TValue">Semantic value type</typeparam>
+    /// <typeparam name="TSpan">Location type</typeparam>
+#if EXPORT_GPPG
+    public abstract class ShiftReduceParser<TValue, TSpan>
+#else
+    internal abstract class ShiftReduceParser<TValue, TSpan>
+#endif
+ where TSpan : IMerge<TSpan>, new() {
+        private AbstractScanner<TValue, TSpan> scanner;
+        /// <summary>
+        /// The abstract scanner for this parser.
+        /// </summary>
+        protected AbstractScanner<TValue, TSpan> Scanner {
+            get { return scanner; }
+            set { scanner = value; }
+        }
+
+        /// <summary>
+        /// Constructor for base class
+        /// </summary>
+        /// <param name="scanner">Scanner instance for this parser</param>
+        protected ShiftReduceParser( AbstractScanner<TValue, TSpan> scanner ) {
+            this.scanner = scanner;
+        }
+
+        // ==============================================================
+        //                    TECHNICAL EXPLANATION.
+        //   Why the next two fields are not exposed via properties.
+        // ==============================================================
+        // These fields are of the generic parameter types, and are
+        // frequently instantiated as struct types in derived classes.
+        // Semantic actions are defined in the derived classes and refer
+        // to instance fields of these structs.  In such cases the code
+        // "get_CurrentSemanticValue().myField = blah;" will fail since
+        // the getter pushes the value of the field, not the reference.
+        // So, in the presence of properties, gppg would need to encode
+        // such field accesses as ... 
+        //  "tmp = get_CurrentSemanticValue(); // Fetch value
+        //   tmp.myField = blah;               // update
+        //   set_CurrentSemanticValue(tmp); "  // Write update back.
+        // There is no issue if TValue is restricted to be a ref type.
+        // The same explanation applies to scanner.yylval.
+        // ==============================================================
+        /// <summary>
+        /// The current value of the "$$" symbolic variable in the parser
+        /// </summary>
+        [SuppressMessage( "Microsoft.Design", "CA1051:DoNotDeclareVisibleInstanceFields" )]
+        protected TValue CurrentSemanticValue;
+
+        /// <summary>
+        /// The current value of the "@$" symbolic variable in the parser
+        /// </summary>
+        [SuppressMessage( "Microsoft.Design", "CA1051:DoNotDeclareVisibleInstanceFields" )]
+        protected TSpan CurrentLocationSpan;
+        protected int NextToken;
+
+        private TSpan LastSpan;
+        private State FsaState;
+        private bool recovering;
+        private int tokensSinceLastError;
+
+        private PushdownPrefixState<State> StateStack = new PushdownPrefixState<State>();
+        private PushdownPrefixState<TValue> valueStack = new PushdownPrefixState<TValue>();
+        private PushdownPrefixState<TSpan> locationStack = new PushdownPrefixState<TSpan>();
+
+        /// <summary>
+        /// The stack of semantic value (YYSTYPE) values.
+        /// </summary>
+        protected PushdownPrefixState<TValue> ValueStack { get { return valueStack; } }
+
+        /// <summary>
+        /// The stack of location value (YYLTYPE) varlues.
+        /// </summary>
+        protected PushdownPrefixState<TSpan> LocationStack { get { return locationStack; } }
+
+        private int errorToken;
+        private int endOfFileToken;
+        private string[] nonTerminals;
+        private State[] states;
+        private Rule[] rules;
+
+        /// <summary>
+        /// Initialization method to allow derived classes
+        /// to insert the rule list into this base class.
+        /// </summary>
+        /// <param name="rules">The array of Rule objects</param>
+        protected void InitRules( Rule[] rules ) { this.rules = rules; }
+
+        /// <summary>
+        /// Initialization method to allow derived classes to
+        /// insert the states table into this base class.
+        /// </summary>
+        /// <param name="states">The pre-initialized states table</param>
+        protected void InitStates( State[] states ) { this.states = states; }
+
+        /// <summary>
+        /// OBSOLETE FOR VERSION 1.4.0
+        /// </summary>
+        /// <param name="size"></param>
+        protected void InitStateTable( int size ) { states = new State[size]; }
+
+        /// <summary>
+        /// Initialization method to allow derived classes
+        /// to insert the special value for the error and EOF tokens.
+        /// </summary>
+        /// <param name="err">The error state ordinal</param>
+        /// <param name="end">The EOF stat ordinal</param>
+        protected void InitSpecialTokens( int err, int end ) {
+            errorToken = err;
+            endOfFileToken = end;
+        }
+
+        /// <summary>
+        /// Initialization method to allow derived classes to
+        /// insert the non-terminal symbol names into this base class.
+        /// </summary>
+        /// <param name="names">Non-terminal symbol names</param>
+        protected void InitNonTerminals( string[] names ) { nonTerminals = names; }
+
+        #region YYAbort, YYAccept etcetera.
+        [Serializable]
+        [SuppressMessage( "Microsoft.Design", "CA1064:ExceptionsShouldBePublic" )]
+        // Reason for FxCop message suppression -
+        // This exception cannot escape from the local context
+        private class AcceptException : Exception {
+            internal AcceptException() { }
+            protected AcceptException( SerializationInfo i, StreamingContext c ) : base( i, c ) { }
+        }
+        [Serializable]
+        [SuppressMessage( "Microsoft.Design", "CA1064:ExceptionsShouldBePublic" )]
+        // Reason for FxCop message suppression -
+        // This exception cannot escape from the local context
+        private class AbortException : Exception {
+            internal AbortException() { }
+            protected AbortException( SerializationInfo i, StreamingContext c ) : base( i, c ) { }
+        }
+        [Serializable]
+        [SuppressMessage( "Microsoft.Design", "CA1064:ExceptionsShouldBePublic" )]
+        // Reason for FxCop message suppression -
+        // This exception cannot escape from the local context
+        private class ErrorException : Exception {
+            internal ErrorException() { }
+            protected ErrorException( SerializationInfo i, StreamingContext c ) : base( i, c ) { }
+        }
+
+        // The following methods are only called from within
+        // a semantic action. The thrown exceptions can never
+        // propagate outside the ShiftReduceParser class in 
+        // which they are nested.
+
+        /// <summary>
+        /// Force parser to terminate, returning "true"
+        /// </summary>
+        protected static void YYAccept() { throw new AcceptException(); }
+
+        /// <summary>
+        /// Force parser to terminate, returning "false"
+        /// </summary>
+        protected static void YYAbort() { throw new AbortException(); }
+
+        /// <summary>
+        /// Force parser to terminate, returning
+        /// "false" if error recovery fails.
+        /// </summary>
+        protected static void YYError() { throw new ErrorException(); }
+
+        /// <summary>
+        /// Check if parser in error recovery state.
+        /// </summary>
+        protected bool YYRecovering { get { return recovering; } }
+        #endregion
+
+        /// <summary>
+        /// Abstract base method. ShiftReduceParser calls this
+        /// to initialize the base class data structures.  Concrete
+        /// parser classes must override this method.
+        /// </summary>
+        protected abstract void Initialize();
+
+        /// <summary>
+        /// Main entry point of the Shift-Reduce Parser.
+        /// </summary>
+        /// <returns>True if parse succeeds, else false for
+        /// unrecoverable errors</returns>
+        public bool Parse() {
+            Initialize();	// allow derived classes to instantiate rules, states and nonTerminals
+
+            NextToken = 0;
+            FsaState = states[0];
+
+            StateStack.Push( FsaState );
+            valueStack.Push( CurrentSemanticValue );
+            LocationStack.Push( CurrentLocationSpan );
+
+            while (true) {
+#if TRACE_ACTIONS
+                Console.Error.WriteLine("Entering state {0} ", FsaState.number);
+                DisplayStack();
+#endif
+                int action = FsaState.defaultAction;
+
+                if (FsaState.ParserTable != null) {
+                    if (NextToken == 0) {
+                        // We save the last token span, so that the location span
+                        // of production right hand sides that begin or end with a
+                        // nullable production will be correct.
+                        LastSpan = scanner.yylloc;
+                        NextToken = scanner.yylex();
+#if TRACE_ACTIONS
+                       Console.Error.WriteLine( "Reading: Next token is {0}", TerminalToString( NextToken ) );
+#endif
+                    }
+#if TRACE_ACTIONS
+                    else 
+                        Console.Error.WriteLine( "Next token is still {0}", TerminalToString( NextToken ) );
+#endif
+                    if (FsaState.ParserTable.ContainsKey( NextToken ))
+                        action = FsaState.ParserTable[NextToken];
+                }
+
+                if (action > 0)         // shift
+                {
+                    Shift( action );
+                }
+                else if (action < 0)   // reduce
+                {
+                    try {
+                        Reduce( -action );
+                        if (action == -1)	// accept
+                            return true;
+                    }
+                    catch (AbortException) {
+                            return false;
+                    }
+                    catch (AcceptException) {
+                        return true;
+                    }
+                    catch (ErrorException) {
+                        if (!ErrorRecovery())
+                            return false;
+                        else
+                            throw;  // Rethrow x, preserving information.
+                    }
+                }
+                else if (action == 0 && !ErrorRecovery()) // error
+                    return false;
+            }
+        }
+
+        private void Shift( int stateIndex ) {
+#if TRACE_ACTIONS
+				Console.Error.Write("Shifting token {0}, ", TerminalToString(NextToken));
+#endif
+            FsaState = states[stateIndex];
+
+            valueStack.Push( scanner.yylval );
+            StateStack.Push( FsaState );
+            LocationStack.Push( scanner.yylloc );
+
+            if (recovering) {
+                if (NextToken != errorToken)
+                    tokensSinceLastError++;
+
+                if (tokensSinceLastError > 5)
+                    recovering = false;
+            }
+
+            if (NextToken != endOfFileToken)
+                NextToken = 0;
+        }
+
+        private void Reduce( int ruleNumber ) {
+#if TRACE_ACTIONS
+				DisplayRule(ruleNumber);
+#endif
+            Rule rule = rules[ruleNumber];
+            int rhLen = rule.RightHandSide.Length;
+            //
+            //  Default actions for unit productions.
+            //
+            if (rhLen == 1) {
+                CurrentSemanticValue = valueStack.TopElement();   // Default action: $$ = $1;
+                CurrentLocationSpan = LocationStack.TopElement(); // Default action "@$ = @1;
+            }
+            else if (rhLen == 0) {
+                // Create a new blank value.
+                // Explicit semantic action may mutate this value
+                CurrentSemanticValue = default( TValue );
+                // The location span for an empty production will start with the
+                // beginning of the next lexeme, and end with the finish of the
+                // previous lexeme.  This gives the correct behaviour when this
+                // nonsense value is used in later Merge operations.
+                CurrentLocationSpan = (scanner.yylloc != null && LastSpan != null ?
+                    scanner.yylloc.Merge( LastSpan ) :
+                    default( TSpan ));
+            }
+            else {
+                // Default action: $$ = $1;
+                CurrentSemanticValue = valueStack[LocationStack.Depth - rhLen];
+                //  Default action "@$ = @1.Merge(@N)" for location info.
+                TSpan at1 = LocationStack[LocationStack.Depth - rhLen];
+                TSpan atN = LocationStack[LocationStack.Depth - 1];
+                CurrentLocationSpan =
+                    ((at1 != null && atN != null) ? at1.Merge( atN ) : default( TSpan ));
+            }
+
+            DoAction( ruleNumber );
+
+            for (int i = 0; i < rule.RightHandSide.Length; i++) {
+                StateStack.Pop();
+                valueStack.Pop();
+                LocationStack.Pop();
+            }
+            FsaState = StateStack.TopElement();
+
+            if (FsaState.Goto.ContainsKey( rule.LeftHandSide ))
+                FsaState = states[FsaState.Goto[rule.LeftHandSide]];
+
+            StateStack.Push( FsaState );
+            valueStack.Push( CurrentSemanticValue );
+            LocationStack.Push( CurrentLocationSpan );
+        }
+
+        /// <summary>
+        /// Execute the selected action from array.
+        /// Must be overriden in derived classes.
+        /// </summary>
+        /// <param name="actionNumber">Index of the action to perform</param>
+        protected abstract void DoAction( int actionNumber );
+
+        private bool ErrorRecovery() {
+            bool discard;
+
+            if (!recovering) // if not recovering from previous error
+                ReportError();
+
+            if (!FindErrorRecoveryState())
+                return false;
+            //
+            //  The interim fix for the "looping in error recovery"
+            //  artifact involved moving the setting of the recovering 
+            //  bool until after invalid tokens have been discarded.
+            //
+            ShiftErrorToken();
+            discard = DiscardInvalidTokens();
+            recovering = true;
+            tokensSinceLastError = 0;
+            return discard;
+        }
+
+        private void ReportError() {
+            StringBuilder errorMsg = new StringBuilder();
+            errorMsg.AppendFormat( "Syntax error, unexpected {0}", TerminalToString( NextToken ) );
+
+            if (FsaState.ParserTable.Count < 7) {
+                bool first = true;
+                foreach (int terminal in FsaState.ParserTable.Keys) {
+                    if (first)
+                        errorMsg.Append( ", expecting " );
+                    else
+                        errorMsg.Append( ", or " );
+
+                    errorMsg.Append( TerminalToString( terminal ) );
+                    first = false;
+                }
+            }
+            scanner.yyerror( errorMsg.ToString() );
+        }
+
+        private void ShiftErrorToken() {
+            int old_next = NextToken;
+            NextToken = errorToken;
+
+            Shift( FsaState.ParserTable[NextToken] );
+
+#if TRACE_ACTIONS
+				Console.Error.WriteLine("Entering state {0} ", FsaState.number);
+#endif
+            NextToken = old_next;
+        }
+
+        private bool FindErrorRecoveryState() {
+            while (true)    // pop states until one found that accepts error token
+            {
+                if (FsaState.ParserTable != null &&
+                    FsaState.ParserTable.ContainsKey( errorToken ) &&
+                    FsaState.ParserTable[errorToken] > 0) // shift
+                    return true;
+
+#if TRACE_ACTIONS
+					Console.Error.WriteLine("Error: popping state {0}", StateStack.TopElement().number);
+#endif
+                StateStack.Pop();
+                valueStack.Pop();
+                LocationStack.Pop();
+
+#if TRACE_ACTIONS
+			    DisplayStack();
+#endif
+                if (StateStack.IsEmpty()) {
+#if TRACE_ACTIONS
+                        Console.Error.WriteLine("Aborting: didn't find a state that accepts error token");
+#endif
+                    return false;
+                }
+                else
+                    FsaState = StateStack.TopElement();
+            }
+        }
+
+        private bool DiscardInvalidTokens() {
+
+            int action = FsaState.defaultAction;
+
+            if (FsaState.ParserTable != null) {
+                // Discard tokens until find one that works ...
+                while (true) {
+                    if (NextToken == 0) {
+#if TRACE_ACTIONS
+                            Console.Error.Write("Reading a token: ");
+#endif
+                        NextToken = scanner.yylex();
+                    }
+#if TRACE_ACTIONS
+                        Console.Error.WriteLine("Next token is {0}", TerminalToString(NextToken));
+#endif
+                    if (NextToken == endOfFileToken)
+                        return false;
+
+                    if (FsaState.ParserTable.ContainsKey( NextToken ))
+                        action = FsaState.ParserTable[NextToken];
+
+                    if (action != 0)
+                        return true;
+                    else {
+#if TRACE_ACTIONS
+                            Console.Error.WriteLine("Error: Discarding {0}", TerminalToString(NextToken));
+#endif
+                        NextToken = 0;
+                    }
+                }
+            }
+            else if (recovering && tokensSinceLastError == 0) {
+                // 
+                //  Boolean recovering is not set until after the first
+                //  error token has been shifted.  Thus if we get back 
+                //  here with recovering set and no tokens read we are
+                //  looping on the same error recovery action.  This 
+                //  happens if current_state.ParserTable is null because
+                //  the state has an LR(0) reduction, but not all
+                //  lookahead tokens are valid.  This only occurs for
+                //  error productions that *end* on "error".
+                //
+                //  This action discards tokens one at a time until
+                //  the looping stops.  Another attack would be to always
+                //  use the LALR(1) table if a production ends on "error"
+                //
+#if TRACE_ACTIONS
+                    Console.Error.WriteLine("Error: panic discard of {0}", TerminalToString(NextToken));
+#endif
+                if (NextToken == endOfFileToken)
+                    return false;
+                NextToken = 0;
+                return true;
+            }
+            else
+                return true;
+        }
+
+        /// <summary>
+        /// Traditional YACC method.  Discards the next input token.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yyclearin" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yyclearin" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        protected void yyclearin() { NextToken = 0; }
+
+        /// <summary>
+        /// Tradional YACC method. Clear the "recovering" flag.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yyerrok" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yyerrok" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        protected void yyerrok() { recovering = false; }
+
+        /// <summary>
+        /// OBSOLETE FOR VERSION 1.4.0
+        /// Method used by derived types to insert new
+        /// state instances in the "states" array.
+        /// </summary>
+        /// <param name="stateNumber">index of the state</param>
+        /// <param name="state">data for the state</param>
+        protected void AddState( int stateNumber, State state ) {
+            states[stateNumber] = state;
+            state.number = stateNumber;
+        }
+
+        private void DisplayStack() {
+            Console.Error.Write( "State stack is now:" );
+            for (int i = 0; i < StateStack.Depth; i++)
+                Console.Error.Write( " {0}", StateStack[i].number );
+            Console.Error.WriteLine();
+        }
+
+        private void DisplayRule( int ruleNumber ) {
+            Console.Error.Write( "Reducing stack by rule {0}, ", ruleNumber );
+            DisplayProduction( rules[ruleNumber] );
+        }
+
+        private void DisplayProduction( Rule rule ) {
+            if (rule.RightHandSide.Length == 0)
+                Console.Error.Write( "/* empty */ " );
+            else
+                foreach (int symbol in rule.RightHandSide)
+                    Console.Error.Write( "{0} ", SymbolToString( symbol ) );
+
+            Console.Error.WriteLine( "-> {0}", SymbolToString( rule.LeftHandSide ) );
+        }
+
+        /// <summary>
+        /// Abstract state class naming terminal symbols.
+        /// This is overridden by derived classes with the
+        /// name (or alias) to be used in error messages.
+        /// </summary>
+        /// <param name="terminal">The terminal ordinal</param>
+        /// <returns></returns>
+        protected abstract string TerminalToString( int terminal );
+
+        private string SymbolToString( int symbol ) {
+            if (symbol < 0)
+                return nonTerminals[-symbol - 1];
+            else
+                return TerminalToString( symbol );
+        }
+
+        /// <summary>
+        /// Return text representation of argument character
+        /// </summary>
+        /// <param name="input">The character to convert</param>
+        /// <returns>String representation of the character</returns>
+        protected static string CharToString( char input ) {
+            switch (input) {
+                case '\a': return @"'\a'";
+                case '\b': return @"'\b'";
+                case '\f': return @"'\f'";
+                case '\n': return @"'\n'";
+                case '\r': return @"'\r'";
+                case '\t': return @"'\t'";
+                case '\v': return @"'\v'";
+                case '\0': return @"'\0'";
+                default: return string.Format( CultureInfo.InvariantCulture, "'{0}'", input );
+            }
+        }
+    }
+
+    /// <summary>
+    /// Classes implementing this interface must supply a
+    /// method that merges two location objects to return
+    /// a new object of the same type.
+    /// GPPG-generated parsers have the default location
+    /// action equivalent to "@$ = @1.Merge(@N);" where N
+    /// is the right-hand-side length of the production.
+    /// </summary>
+    /// <typeparam name="TSpan">The Location type</typeparam>
+#if EXPORT_GPPG
+    public interface IMerge<TSpan>
+#else
+    internal interface IMerge<TSpan>
+#endif
+ {
+        /// <summary>
+        /// Interface method that creates a location object from
+        /// the current and last object.  Typically used to create
+        /// a location object extending from the start of the @1
+        /// object to the end of the @N object.
+        /// </summary>
+        /// <param name="last">The lexically last object to merge</param>
+        /// <returns>The merged location object</returns>
+        TSpan Merge( TSpan last );
+    }
+
+    /// <summary>
+    /// This is the default class that carries location
+    /// information from the scanner to the parser.
+    /// If you don't declare "%YYLTYPE Foo" the parser
+    /// will expect to deal with this type.
+    /// </summary>
+#if EXPORT_GPPG
+    public class LexLocation : IMerge<LexLocation>
+#else
+    [SuppressMessage( "Microsoft.Performance", "CA1812:AvoidUninstantiatedInternalClasses" )]
+    internal class LexLocation : IMerge<LexLocation>
+#endif
+ {
+        private int startLine;   // start line
+        private int startColumn; // start column
+        private int endLine;     // end line
+        private int endColumn;   // end column
+
+        /// <summary>
+        /// The line at which the text span starts.
+        /// </summary>
+        public int StartLine { get { return startLine; } }
+
+        /// <summary>
+        /// The column at which the text span starts.
+        /// </summary>
+        public int StartColumn { get { return startColumn; } }
+
+        /// <summary>
+        /// The line on which the text span ends.
+        /// </summary>
+        public int EndLine { get { return endLine; } }
+
+        /// <summary>
+        /// The column of the first character
+        /// beyond the end of the text span.
+        /// </summary>
+        public int EndColumn { get { return endColumn; } }
+
+        /// <summary>
+        /// Default no-arg constructor.
+        /// </summary>
+        public LexLocation() { }
+
+        /// <summary>
+        /// Constructor for text-span with given start and end.
+        /// </summary>
+        /// <param name="sl">start line</param>
+        /// <param name="sc">start column</param>
+        /// <param name="el">end line </param>
+        /// <param name="ec">end column</param>
+        public LexLocation( int sl, int sc, int el, int ec ) { startLine = sl; startColumn = sc; endLine = el; endColumn = ec; }
+
+        /// <summary>
+        /// Create a text location which spans from the 
+        /// start of "this" to the end of the argument "last"
+        /// </summary>
+        /// <param name="last">The last location in the result span</param>
+        /// <returns>The merged span</returns>
+        public LexLocation Merge( LexLocation last ) { return new LexLocation( this.startLine, this.startColumn, last.endLine, last.endColumn ); }
+    }
+
+    /// <summary>
+    /// Abstract scanner class that GPPG expects its scanners to 
+    /// extend.
+    /// </summary>
+    /// <typeparam name="TValue">Semantic value type YYSTYPE</typeparam>
+    /// <typeparam name="TSpan">Source location type YYLTYPE</typeparam>
+#if EXPORT_GPPG
+    public abstract class AbstractScanner<TValue, TSpan>
+#else
+    internal abstract class AbstractScanner<TValue, TSpan>
+#endif
+ where TSpan : IMerge<TSpan> {
+        /// <summary>
+        /// Lexical value optionally set by the scanner. The value
+        /// is of the %YYSTYPE type declared in the parser spec.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Design", "CA1051:DoNotDeclareVisibleInstanceFields" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yylval" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yylval" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        // A field must be declared for this value of parametric type,
+        // since it may be instantiated by a value struct.  If it were 
+        // implemented as a property, machine generated code in derived
+        // types would not be able to select on the returned value.
+#pragma warning disable 649
+        public TValue yylval;                     // Lexical value: set by scanner
+#pragma warning restore 649
+
+        /// <summary>
+        /// Current scanner location property. The value is of the
+        /// type declared by %YYLTYPE in the parser specification.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yylloc" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yylloc" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        public virtual TSpan yylloc {
+            get { return default( TSpan ); }       // Empty implementation allowing
+            set { /* skip */ }                   // yylloc to be ignored entirely.
+        }
+
+        /// <summary>
+        /// Main call point for LEX-like scanners.  Returns an int
+        /// corresponding to the token recognized by the scanner.
+        /// </summary>
+        /// <returns>An int corresponding to the token</returns>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yylex" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yylex" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        public abstract int yylex();
+
+        /// <summary>
+        /// Traditional error reporting provided by LEX-like scanners
+        /// to their YACC-like clients.
+        /// </summary>
+        /// <param name="format">Message format string</param>
+        /// <param name="args">Optional array of args</param>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yyerror" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yyerror" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        public virtual void yyerror( string format, params object[] args ) { }
+    }
+
+    /// <summary>
+    /// Encapsulated state for the parser.
+    /// Opaque to users, visible to the tool-generated code.
+    /// </summary>
+#if EXPORT_GPPG
+    public class State
+    {
+        /// <summary>
+        /// The number of states in the automaton.
+        /// </summary>
+        public int number;
+#else
+    internal class State {
+        /// <summary>
+        /// The index of this state in the states array.
+        /// </summary>
+        internal int number;
+#endif
+        internal Dictionary<int, int> ParserTable;   // Terminal -> ParseAction
+        internal Dictionary<int, int> Goto;          // NonTerminal -> State;
+        internal int defaultAction; // = 0;		     // ParseAction
+
+        /// <summary>
+        /// State transition data for this state. Pairs of elements of the 
+        /// goto array associate symbol ordinals with next state indices.
+        /// The actions array is passed to another constructor. 
+        /// </summary>
+        /// <param name="actions">The action list</param>c
+        /// <param name="goToList">Next state data</param>
+        public State( int[] actions, int[] goToList )
+            : this( actions ) {
+            Goto = new Dictionary<int, int>();
+            for (int i = 0; i < goToList.Length; i += 2)
+                Goto.Add( goToList[i], goToList[i + 1] );
+        }
+
+        /// <summary>
+        /// Action data for this state. Pairs of elements of the 
+        /// action array associate action ordinals with each of
+        /// those symbols that have actions in the current state.
+        /// </summary>
+        /// <param name="actions">The action array</param>
+        public State( int[] actions ) {
+            ParserTable = new Dictionary<int, int>();
+            for (int i = 0; i < actions.Length; i += 2)
+                ParserTable.Add( actions[i], actions[i + 1] );
+        }
+
+        /// <summary>
+        /// Set the default action for this state.
+        /// </summary>
+        /// <param name="defaultAction">Ordinal of the default action</param>
+        public State( int defaultAction ) {
+            this.defaultAction = defaultAction;
+        }
+
+        /// <summary>
+        /// Set the default action and the state transition table.
+        /// </summary>
+        /// <param name="defaultAction">The default action</param>
+        /// <param name="goToList">Transitions from this state</param>
+        public State( int defaultAction, int[] goToList )
+            : this( defaultAction ) {
+            Goto = new Dictionary<int, int>();
+            for (int i = 0; i < goToList.Length; i += 2)
+                Goto.Add( goToList[i], goToList[i + 1] );
+        }
+    }
+
+    /// <summary>
+    /// Rule representation at runtime.
+    /// </summary>
+#if EXPORT_GPPG
+    public class Rule
+#else
+    internal class Rule
+#endif
+ {
+        internal int LeftHandSide; // symbol
+        internal int[] RightHandSide; // symbols
+
+        /// <summary>
+        /// Rule constructor.  This holds the ordinal of
+        /// the left hand side symbol, and the list of
+        /// right hand side symbols, in lexical order.
+        /// </summary>
+        /// <param name="left">The LHS non-terminal</param>
+        /// <param name="right">The RHS symbols, in lexical order</param>
+        public Rule( int left, int[] right ) {
+            this.LeftHandSide = left;
+            this.RightHandSide = right;
+        }
+    }
+
+    /// <summary>
+    /// Stack utility for the shift-reduce parser.
+    /// GPPG parsers have three instances:
+    /// (1) The parser state stack, T = QUT.Gppg.State,
+    /// (2) The semantic value stack, T = TValue,
+    /// (3) The location stack, T = TSpan.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+#if EXPORT_GPPG
+    public class PushdownPrefixState<T>
+#else
+    internal class PushdownPrefixState<T>
+#endif
+ {
+        //  Note that we cannot use the BCL Stack<T> class
+        //  here as derived types need to index into stacks.
+        //
+        private T[] array = new T[8];
+        private int tos = 0;
+
+        /// <summary>
+        /// Indexer for values of the stack below the top.
+        /// </summary>
+        /// <param name="index">index of the element, starting from the bottom</param>
+        /// <returns>the selected element</returns>
+        public T this[int index] { get { return array[index]; } }
+
+        /// <summary>
+        /// The current depth of the stack.
+        /// </summary>
+        public int Depth { get { return tos; } }
+
+        internal void Push( T value ) {
+            if (tos >= array.Length) {
+                T[] newarray = new T[array.Length * 2];
+                System.Array.Copy( array, newarray, tos );
+                array = newarray;
+            }
+            array[tos++] = value;
+        }
+
+        internal T Pop() {
+            T rslt = array[--tos];
+            array[tos] = default( T );
+            return rslt;
+        }
+
+        internal T TopElement() { return array[tos - 1]; }
+
+        internal bool IsEmpty() { return tos == 0; }
+    }
+}
+

src/DataStreamSuite/Bts.ColumnExpressions/Usings.cs

@@ -0,0 +1,4 @@
+global using System;
+global using System.Linq;
+global using System.Collections.Generic;
+global using System.Collections.Immutable;

src/DataStreamSuite/Bts.ColumnSortExpressions/Bts.ColumnSortExpressions.csproj

@@ -0,0 +1,24 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net7.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="YaccLexTools" Version="1.2.2" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\DataStreamCore\DataStreamCore.csproj" />
+    <ProjectReference Include="..\ExpressionCore\ExpressionCore.csproj" />
+    <ProjectReference Include="..\..\client\spark_core\spark_core.csproj" />
+  </ItemGroup>
+
+  <ItemGroup Label="ColumnSortExpression">
+    <Scanner Include="ColumnSortExpressionTokens.lex" />
+    <Parser Include="ColumnSortExpressionGrammar.y" />
+  </ItemGroup>
+
+</Project>

src/DataStreamSuite/Bts.ColumnSortExpressions/ColumnSortExpression.cs

@@ -0,0 +1,11 @@
+namespace Bts.ColumnSortExpressions;
+
+public class ColumnSortExpression {
+   public ColumnSortExpression(string name, bool isAscending = true) {
+      Name = name;
+      IsAscending = isAscending;
+   }
+
+   public string Name { get; }
+   public bool IsAscending { get; }
+}

src/DataStreamSuite/Bts.ColumnSortExpressions/ColumnSortExpressionGrammar.y

@@ -0,0 +1,29 @@
+%namespace Bts.ColumnSortExpressions
+%partial
+%visibility internal
+%tokentype ColumnSortExpressionToken
+%parsertype ColumnSortExpressionParser
+
+%union {
+   public string Identifier;
+   public ColumnSortExpression Column;
+   public ImmutableList<ColumnSortExpression> Columns;
+}
+
+%token ASCENDING, DESCENDING, IDENTIFIER
+
+%type <Column> Column
+%type <Columns> Columns
+
+%%
+
+Columns :
+   Column { $$ = ImmutableList.CreateRange(new[] { $1 }); }
+   | Columns Column { $$ = $1.Add($2); }
+   ;
+
+Column :
+   IDENTIFIER { $$ = new($1.Identifier, true); }
+   | ASCENDING IDENTIFIER { $$ = new($2.Identifier, true); }
+   | DESCENDING IDENTIFIER { $$ = new($2.Identifier, false); }
+   ;

src/DataStreamSuite/Bts.ColumnSortExpressions/ColumnSortExpressionInterpreter.cs

@@ -0,0 +1,18 @@
+namespace Bts.ColumnSortExpressions;
+
+using System.IO;
+using System.Text;
+
+public class ColumnSortExpressionInterpreter {
+   public static IList<ColumnSortExpression> Evaluate(Stream stream) {
+      var parser = new ColumnSortExpressionParser();
+      var res = parser.Parse(stream);
+      return res?.Columns ?? ImmutableList<ColumnSortExpression>.Empty.Add(
+         res?.Column ?? throw new Exception("Failed to parse column(s) expression"));
+   }
+
+   public static IList<ColumnSortExpression> Evaluate(string str) {
+      using var ms = new MemoryStream(Encoding.Default.GetBytes(str));
+      return Evaluate(ms);
+   }
+}

src/DataStreamSuite/Bts.ColumnSortExpressions/ColumnSortExpressionParser.cs

@@ -0,0 +1,18 @@
+namespace Bts.ColumnSortExpressions;
+
+using System.Text;
+
+partial class ColumnSortExpressionParser {
+   public ColumnSortExpressionParser() : base(null) { }
+
+   public ValueType? Parse(string s) {
+      using var ms = new MemoryStream(Encoding.Default.GetBytes(s));
+      return Parse(ms);
+   }
+
+   public ValueType? Parse(Stream stream) {
+      Scanner = new ColumnSortExpressionScanner(stream);
+      Parse();
+      return CurrentSemanticValue;
+   }
+}

src/DataStreamSuite/Bts.ColumnSortExpressions/ColumnSortExpressionScanner.cs

@@ -0,0 +1,9 @@
+namespace Bts.ColumnSortExpressions;
+
+partial class ColumnSortExpressionScanner {
+   public override void yyerror(string format, params object[] args) {
+      base.yyerror(format, args);
+      Console.WriteLine(format, args);
+      Console.WriteLine();
+   }
+}

src/DataStreamSuite/Bts.ColumnSortExpressions/ColumnSortExpressionTokens.lex

@@ -0,0 +1,30 @@
+%namespace Bts.ColumnSortExpressions
+%scannertype ColumnSortExpressionScanner
+%visibility internal
+%tokentype ColumnSortExpressionToken
+
+%option stack, minimize, parser, verbose, persistbuffer, noembedbuffers 
+
+/* Literal Constants */
+Letter                   [a-zA-Z]
+
+Identifier               {Letter}({Letter}*[0-9]*_*)*
+Ascending                +
+Descending               -
+
+%%
+
+{Ascending} {
+   return (int)ColumnSortExpressionToken.ASCENDING;
+}
+
+{Descending} {
+   return (int)ColumnSortExpressionToken.DESCENDING;
+}
+
+{Identifier} {
+   yylval.Identifier = yytext;
+   return (int)ColumnSortExpressionToken.IDENTIFIER;
+}
+
+%%

src/DataStreamSuite/Bts.ColumnSortExpressions/GplexBuffers.cs

@@ -0,0 +1,720 @@
+// ==============================================================
+// <auto-generated>
+// This code automatically produced from an embedded resource.
+// Do not edit this file, or it will become incompatible with 
+// the specification from which it was generated.
+// </auto-generated>
+// ==============================================================
+
+using System;
+using System.IO;
+using System.Text;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Runtime.Serialization;
+using System.Globalization;
+
+namespace QUT.GplexBuffers
+{
+// Code copied from GPLEX embedded resource
+    [Serializable]
+    internal class BufferException : Exception
+    {
+        public BufferException() { }
+        public BufferException(string message) : base(message) { }
+        public BufferException(string message, Exception innerException)
+            : base(message, innerException) { }
+        protected BufferException(SerializationInfo info, StreamingContext context)
+            : base(info, context) { }
+    }
+
+    internal abstract class ScanBuff
+    {
+        private string fileNm;
+
+        public const int EndOfFile = -1;
+        public const int UnicodeReplacementChar = 0xFFFD;
+
+        public bool IsFile { get { return (fileNm != null); } }
+        public string FileName { get { return fileNm; } set { fileNm = value; } }
+
+        public abstract int Pos { get; set; }
+        public abstract int Read();
+        public virtual void Mark() { }
+
+        public abstract string GetString(int begin, int limit);
+
+        public static ScanBuff GetBuffer(string source)
+        {
+            return new StringBuffer(source);
+        }
+
+        public static ScanBuff GetBuffer(IList<string> source)
+        {
+            return new LineBuffer(source);
+        }
+
+#if (!NOFILES)
+        public static ScanBuff GetBuffer(Stream source)
+        {
+            return new BuildBuffer(source);
+        }
+
+#if (!BYTEMODE)
+        public static ScanBuff GetBuffer(Stream source, int fallbackCodePage)
+        {
+            return new BuildBuffer(source, fallbackCodePage);
+        }
+#endif // !BYTEMODE
+#endif // !NOFILES
+    }
+
+    #region Buffer classes
+
+    // ==============================================================
+    // =====  Definitions for various ScanBuff derived classes   ====
+    // ==============================================================
+    // ===============         String input          ================
+    // ==============================================================
+
+    /// <summary>
+    /// This class reads characters from a single string as
+    /// required, for example, by Visual Studio language services
+    /// </summary>
+    sealed class StringBuffer : ScanBuff
+    {
+        string str;        // input buffer
+        int bPos;          // current position in buffer
+        int sLen;
+
+        public StringBuffer(string source)
+        {
+            this.str = source;
+            this.sLen = source.Length;
+            this.FileName = null;
+        }
+
+        public override int Read()
+        {
+            if (bPos < sLen) return str[bPos++];
+            else if (bPos == sLen) { bPos++; return '\n'; }   // one strike, see new line
+            else { bPos++; return EndOfFile; }                // two strikes and you're out!
+        }
+
+        public override string GetString(int begin, int limit)
+        {
+            //  "limit" can be greater than sLen with the BABEL
+            //  option set.  Read returns a "virtual" EOL if
+            //  an attempt is made to read past the end of the
+            //  string buffer.  Without the guard any attempt 
+            //  to fetch yytext for a token that includes the 
+            //  EOL will throw an index exception.
+            if (limit > sLen) limit = sLen;
+            if (limit <= begin) return "";
+            else return str.Substring(begin, limit - begin);
+        }
+
+        public override int Pos
+        {
+            get { return bPos; }
+            set { bPos = value; }
+        }
+
+        public override string ToString() { return "StringBuffer"; }
+    }
+
+    // ==============================================================
+    //  The LineBuff class contributed by Nigel Horspool, 
+    //  nigelh@cs.uvic.cs
+    // ==============================================================
+
+    sealed class LineBuffer : ScanBuff
+    {
+        IList<string> line;    // list of source lines from a file
+        int numLines;          // number of strings in line list
+        string curLine;        // current line in that list
+        int cLine;             // index of current line in the list
+        int curLen;            // length of current line
+        int curLineStart;      // position of line start in whole file
+        int curLineEnd;        // position of line end in whole file
+        int maxPos;            // max position ever visited in whole file
+        int cPos;              // ordinal number of code in source
+
+        // Constructed from a list of strings, one per source line.
+        // The lines have had trailing '\n' characters removed.
+        public LineBuffer(IList<string> lineList)
+        {
+            line = lineList;
+            numLines = line.Count;
+            cPos = curLineStart = 0;
+            curLine = (numLines > 0 ? line[0] : "");
+            maxPos = curLineEnd = curLen = curLine.Length;
+            cLine = 1;
+            FileName = null;
+        }
+
+        public override int Read()
+        {
+            if (cPos < curLineEnd)
+                return curLine[cPos++ - curLineStart];
+            if (cPos++ == curLineEnd)
+                return '\n';
+            if (cLine >= numLines)
+                return EndOfFile;
+            curLine = line[cLine];
+            curLen = curLine.Length;
+            curLineStart = curLineEnd + 1;
+            curLineEnd = curLineStart + curLen;
+            if (curLineEnd > maxPos)
+                maxPos = curLineEnd;
+            cLine++;
+            return curLen > 0 ? curLine[0] : '\n';
+        }
+
+        // To speed up searches for the line containing a position
+        private int cachedPosition;
+        private int cachedIxdex;
+        private int cachedLineStart;
+
+        // Given a position pos within the entire source, the results are
+        //   ix     -- the index of the containing line
+        //   lstart -- the position of the first character on that line
+        private void findIndex(int pos, out int ix, out int lstart)
+        {
+            if (pos >= cachedPosition)
+            {
+                ix = cachedIxdex; lstart = cachedLineStart;
+            }
+            else
+            {
+                ix = lstart = 0;
+            }
+            while (ix < numLines)
+            {
+                int len = line[ix].Length + 1;
+                if (pos < lstart + len) break;
+                lstart += len;
+                ix++;
+            }
+            cachedPosition = pos;
+            cachedIxdex = ix;
+            cachedLineStart = lstart;
+        }
+
+        public override string GetString(int begin, int limit)
+        {
+            if (begin >= maxPos || limit <= begin) return "";
+            int endIx, begIx, endLineStart, begLineStart;
+            findIndex(begin, out begIx, out begLineStart);
+            int begCol = begin - begLineStart;
+            findIndex(limit, out endIx, out endLineStart);
+            int endCol = limit - endLineStart;
+            string s = line[begIx];
+            if (begIx == endIx)
+            {
+                // the usual case, substring all on one line
+                return (endCol <= s.Length) ?
+                    s.Substring(begCol, endCol - begCol)
+                    : s.Substring(begCol) + "\n";
+            }
+            // the string spans multiple lines, yuk!
+            StringBuilder sb = new StringBuilder();
+            if (begCol < s.Length)
+                sb.Append(s.Substring(begCol));
+            for (; ; )
+            {
+                sb.Append("\n");
+                s = line[++begIx];
+                if (begIx >= endIx) break;
+                sb.Append(s);
+            }
+            if (endCol <= s.Length)
+            {
+                sb.Append(s.Substring(0, endCol));
+            }
+            else
+            {
+                sb.Append(s);
+                sb.Append("\n");
+            }
+            return sb.ToString();
+        }
+
+        public override int Pos
+        {
+            get { return cPos; }
+            set
+            {
+                cPos = value;
+                findIndex(cPos, out cLine, out curLineStart);
+                // cLine should be the *next* line after curLine.
+                curLine = (cLine < numLines ? line[cLine++] : "");
+                curLineEnd = curLineStart + curLine.Length;
+            }
+        }
+
+        public override string ToString() { return "LineBuffer"; }
+    }
+
+#if (!NOFILES)
+    // ==============================================================
+    // =====     class BuildBuff : for unicode text files    ========
+    // ==============================================================
+
+    class BuildBuffer : ScanBuff
+    {
+        // Double buffer for char stream.
+        class BufferElement
+        {
+            StringBuilder bldr = new StringBuilder();
+            StringBuilder next = new StringBuilder();
+            int minIx;
+            int maxIx;
+            int brkIx;
+            bool appendToNext;
+
+            internal BufferElement() { }
+
+            internal int MaxIndex { get { return maxIx; } }
+            // internal int MinIndex { get { return minIx; } }
+
+            internal char this[int index]
+            {
+                get
+                {
+                    if (index < minIx || index >= maxIx)
+                        throw new BufferException("Index was outside data buffer");
+                    else if (index < brkIx)
+                        return bldr[index - minIx];
+                    else
+                        return next[index - brkIx];
+                }
+            }
+
+            internal void Append(char[] block, int count)
+            {
+                maxIx += count;
+                if (appendToNext)
+                    this.next.Append(block, 0, count);
+                else
+                {
+                    this.bldr.Append(block, 0, count);
+                    brkIx = maxIx;
+                    appendToNext = true;
+                }
+            }
+
+            internal string GetString(int start, int limit)
+            {
+                if (limit <= start)
+                    return "";
+                if (start >= minIx && limit <= maxIx)
+                    if (limit < brkIx) // String entirely in bldr builder
+                        return bldr.ToString(start - minIx, limit - start);
+                    else if (start >= brkIx) // String entirely in next builder
+                        return next.ToString(start - brkIx, limit - start);
+                    else // Must do a string-concatenation
+                        return
+                            bldr.ToString(start - minIx, brkIx - start) +
+                            next.ToString(0, limit - brkIx);
+                else
+                    throw new BufferException("String was outside data buffer");
+            }
+
+            internal void Mark(int limit)
+            {
+                if (limit > brkIx + 16) // Rotate blocks
+                {
+                    StringBuilder temp = bldr;
+                    bldr = next;
+                    next = temp;
+                    next.Length = 0;
+                    minIx = brkIx;
+                    brkIx = maxIx;
+                }
+            }
+        }
+
+        BufferElement data = new BufferElement();
+
+        int bPos;            // Postion index in the StringBuilder
+        BlockReader NextBlk; // Delegate that serves char-arrays;
+
+        private string EncodingName
+        {
+            get
+            {
+                StreamReader rdr = NextBlk.Target as StreamReader;
+                return (rdr == null ? "raw-bytes" : rdr.CurrentEncoding.BodyName);
+            }
+        }
+
+        public BuildBuffer(Stream stream)
+        {
+            FileStream fStrm = (stream as FileStream);
+            if (fStrm != null) FileName = fStrm.Name;
+            NextBlk = BlockReaderFactory.Raw(stream);
+        }
+
+#if (!BYTEMODE)
+        public BuildBuffer(Stream stream, int fallbackCodePage)
+        {
+            FileStream fStrm = (stream as FileStream);
+            if (fStrm != null) FileName = fStrm.Name;
+            NextBlk = BlockReaderFactory.Get(stream, fallbackCodePage);
+        }
+#endif
+
+        /// <summary>
+        /// Marks a conservative lower bound for the buffer,
+        /// allowing space to be reclaimed.  If an application 
+        /// needs to call GetString at arbitrary past locations 
+        /// in the input stream, Mark() is not called.
+        /// </summary>
+        public override void Mark() { data.Mark(bPos - 2); }
+
+        public override int Pos
+        {
+            get { return bPos; }
+            set { bPos = value; }
+        }
+
+
+        /// <summary>
+        /// Read returns the ordinal number of the next char, or 
+        /// EOF (-1) for an end of stream.  Note that the next
+        /// code point may require *two* calls of Read().
+        /// </summary>
+        /// <returns></returns>
+        public override int Read()
+        {
+            //
+            //  Characters at positions 
+            //  [data.offset, data.offset + data.bldr.Length)
+            //  are available in data.bldr.
+            //
+            if (bPos < data.MaxIndex)
+            {
+                // ch0 cannot be EOF
+                return (int)data[bPos++];
+            }
+            else // Read from underlying stream
+            {
+                // Experimental code, blocks of page size
+                char[] chrs = new char[4096];
+                int count = NextBlk(chrs, 0, 4096);
+                if (count == 0)
+                    return EndOfFile;
+                else
+                {
+                    data.Append(chrs, count);
+                    return (int)data[bPos++];
+                }
+            }
+        }
+
+        public override string GetString(int begin, int limit)
+        {
+            return data.GetString(begin, limit);
+        }
+
+        public override string ToString()
+        {
+            return "StringBuilder buffer, encoding: " + this.EncodingName;
+        }
+    }
+
+    // =============== End ScanBuff-derived classes ==================
+
+    internal delegate int BlockReader(char[] block, int index, int number);
+
+    // A delegate factory, serving up a delegate that
+    // reads a block of characters from the underlying
+    // encoded stream, via a StreamReader object.
+    //
+    internal static class BlockReaderFactory
+    {
+        public static BlockReader Raw(Stream stream)
+        {
+            return delegate(char[] block, int index, int number)
+            {
+                byte[] b = new byte[number];
+                int count = stream.Read(b, 0, number);
+                int i = 0;
+                int j = index;
+                for (; i < count; i++, j++)
+                    block[j] = (char)b[i];
+                return count;
+            };
+        }
+
+#if (!BYTEMODE)
+        public static BlockReader Get(Stream stream, int fallbackCodePage)
+        {
+            Encoding encoding;
+            int preamble = Preamble(stream);
+
+            if (preamble != 0)  // There is a valid BOM here!
+                encoding = Encoding.GetEncoding(preamble);
+            else if (fallbackCodePage == -1) // Fallback is "raw" bytes
+                return Raw(stream);
+            else if (fallbackCodePage != -2) // Anything but "guess"
+                encoding = Encoding.GetEncoding(fallbackCodePage);
+            else // This is the "guess" option
+            {
+                int guess = new Guesser(stream).GuessCodePage();
+                stream.Seek(0, SeekOrigin.Begin);
+                if (guess == -1) // ==> this is a 7-bit file
+                    encoding = Encoding.ASCII;
+                else if (guess == 65001)
+                    encoding = Encoding.UTF8;
+                else             // ==> use the machine default
+                    encoding = Encoding.Default;
+            }
+            StreamReader reader = new StreamReader(stream, encoding);
+            return reader.Read;
+        }
+
+        static int Preamble(Stream stream)
+        {
+            int b0 = stream.ReadByte();
+            int b1 = stream.ReadByte();
+
+            if (b0 == 0xfe && b1 == 0xff)
+                return 1201; // UTF16BE
+            if (b0 == 0xff && b1 == 0xfe)
+                return 1200; // UTF16LE
+
+            int b2 = stream.ReadByte();
+            if (b0 == 0xef && b1 == 0xbb && b2 == 0xbf)
+                return 65001; // UTF8
+            //
+            // There is no unicode preamble, so we
+            // return denoter for the machine default.
+            //
+            stream.Seek(0, SeekOrigin.Begin);
+            return 0;
+        }
+#endif // !BYTEMODE
+    }
+#endif // !NOFILES
+    #endregion Buffer classes
+
+    // ==============================================================
+    // ============      class CodePageHandling         =============
+    // ==============================================================
+#if (!NOFILES)
+    public static class CodePageHandling
+    {
+        public static int GetCodePage(string option)
+        {
+            string command = option.ToUpperInvariant();
+            if (command.StartsWith("CodePage:", StringComparison.OrdinalIgnoreCase))
+                command = command.Substring(9);
+            try
+            {
+                if (command.Equals("RAW"))
+                    return -1;
+                else if (command.Equals("GUESS"))
+                    return -2;
+                else if (command.Equals("DEFAULT"))
+                    return 0;
+                else if (char.IsDigit(command[0]))
+                    return int.Parse(command, CultureInfo.InvariantCulture);
+                else
+                {
+                    Encoding enc = Encoding.GetEncoding(command);
+                    return enc.CodePage;
+                }
+            }
+            catch (FormatException)
+            {
+                Console.Error.WriteLine(
+                    "Invalid format \"{0}\", using machine default", option);
+            }
+            catch (ArgumentException)
+            {
+                Console.Error.WriteLine(
+                    "Unknown code page \"{0}\", using machine default", option);
+            }
+            return 0;
+        }
+    }
+#region guesser
+#if (!BYTEMODE)
+    // ==============================================================
+    // ============          Encoding Guesser           =============
+    // ==============================================================
+
+    /// <summary>
+    /// This class provides a simple finite state automaton that
+    /// scans the file looking for (1) valid UTF-8 byte patterns,
+    /// (2) bytes >= 0x80 which are not part of a UTF-8 sequence.
+    /// The method then guesses whether it is UTF-8 or maybe some 
+    /// local machine default encoding.  This works well for the
+    /// various Latin encodings.
+    /// </summary>
+    internal class Guesser
+    {
+        ScanBuff buffer;
+
+        public int GuessCodePage() { return Scan(); }
+
+        const int maxAccept = 10;
+        const int initial = 0;
+        const int eofNum = 0;
+        const int goStart = -1;
+        const int INITIAL = 0;
+        const int EndToken = 0;
+
+        #region user code
+        /* 
+         *  Reads the bytes of a file to determine if it is 
+         *  UTF-8 or a single-byte code page file.
+         */
+        public long utfX;
+        public long uppr;
+        #endregion user code
+
+        int state;
+        int currentStart = startState[0];
+        int code;
+
+        #region ScannerTables
+        static int[] startState = new int[] { 11, 0 };
+
+        #region CharacterMap
+        static sbyte[] map = new sbyte[256] {
+/*     '\0' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*   '\x10' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*   '\x20' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      '0' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      '@' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      'P' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      '`' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*      'p' */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 
+/*   '\x80' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\x90' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\xA0' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\xB0' */ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 
+/*   '\xC0' */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
+/*   '\xD0' */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 
+/*   '\xE0' */ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 
+/*   '\xF0' */ 4, 4, 4, 4, 4, 4, 4, 4, 5, 5, 5, 5, 5, 5, 5, 5 };
+        #endregion
+
+        static sbyte[][] nextState = new sbyte[][] {
+            new sbyte[] {0, 0, 0, 0, 0, 0},
+            new sbyte[] {-1, -1, 10, -1, -1, -1},
+            new sbyte[] {-1, -1, -1, -1, -1, -1},
+            new sbyte[] {-1, -1, 8, -1, -1, -1},
+            new sbyte[] {-1, -1, 5, -1, -1, -1},
+            new sbyte[] {-1, -1, 6, -1, -1, -1},
+            new sbyte[] {-1, -1, 7, -1, -1, -1},
+            null,
+            new sbyte[] {-1, -1, 9, -1, -1, -1},
+            null,
+            null,
+            new sbyte[] {-1, 1, 2, 3, 4, 2}
+        };
+
+
+        [SuppressMessage("Microsoft.Performance", "CA1810:InitializeReferenceTypeStaticFieldsInline")]
+        // Reason for suppression: cannot have self-reference in array initializer.
+        static Guesser()
+        {
+            nextState[7] = nextState[2];
+            nextState[9] = nextState[2];
+            nextState[10] = nextState[2];
+        }
+
+        int NextState()
+        {
+            if (code == ScanBuff.EndOfFile)
+                return eofNum;
+            else
+                return nextState[state][map[code]];
+        }
+        #endregion
+
+        public Guesser(System.IO.Stream file) { SetSource(file); }
+
+        public void SetSource(System.IO.Stream source)
+        {
+            this.buffer = new BuildBuffer(source);
+            code = buffer.Read();
+        }
+
+        int Scan()
+        {
+            for (; ; )
+            {
+                int next;
+                state = currentStart;
+                while ((next = NextState()) == goStart)
+                    code = buffer.Read();
+
+                state = next;
+                code = buffer.Read();
+
+                while ((next = NextState()) > eofNum)
+                {
+                    state = next;
+                    code = buffer.Read();
+                }
+                if (state <= maxAccept)
+                {
+                    #region ActionSwitch
+#pragma warning disable 162
+                    switch (state)
+                    {
+                        case eofNum:
+                            switch (currentStart)
+                            {
+                                case 11:
+                                    if (utfX == 0 && uppr == 0) return -1; /* raw ascii */
+                                    else if (uppr * 10 > utfX) return 0;   /* default code page */
+                                    else return 65001;                     /* UTF-8 encoding */
+                                    break;
+                            }
+                            return EndToken;
+                        case 1: // Recognized '{Upper128}',	Shortest string "\xC0"
+                        case 2: // Recognized '{Upper128}',	Shortest string "\x80"
+                        case 3: // Recognized '{Upper128}',	Shortest string "\xE0"
+                        case 4: // Recognized '{Upper128}',	Shortest string "\xF0"
+                            uppr++;
+                            break;
+                        case 5: // Recognized '{Utf8pfx4}{Utf8cont}',	Shortest string "\xF0\x80"
+                            uppr += 2;
+                            break;
+                        case 6: // Recognized '{Utf8pfx4}{Utf8cont}{2}',	Shortest string "\xF0\x80\x80"
+                            uppr += 3;
+                            break;
+                        case 7: // Recognized '{Utf8pfx4}{Utf8cont}{3}',	Shortest string "\xF0\x80\x80\x80"
+                            utfX += 3;
+                            break;
+                        case 8: // Recognized '{Utf8pfx3}{Utf8cont}',	Shortest string "\xE0\x80"
+                            uppr += 2;
+                            break;
+                        case 9: // Recognized '{Utf8pfx3}{Utf8cont}{2}',	Shortest string "\xE0\x80\x80"
+                            utfX += 2;
+                            break;
+                        case 10: // Recognized '{Utf8pfx2}{Utf8cont}',	Shortest string "\xC0\x80"
+                            utfX++;
+                            break;
+                        default:
+                            break;
+                    }
+#pragma warning restore 162
+                    #endregion
+                }
+            }
+        }
+    } // end class Guesser
+    
+#endif // !BYTEMODE
+#endregion
+#endif // !NOFILES
+
+// End of code copied from embedded resource
+}

src/DataStreamSuite/Bts.ColumnSortExpressions/ShiftReduceParserCode.cs

@@ -0,0 +1,884 @@
+// ==============================================================
+// <auto-generated>
+// This code automatically produced from an embedded resource.
+// Do not edit this file, or it will become incompatible with 
+// the specification from which it was generated.
+// </auto-generated>
+// ==============================================================
+
+// Gardens Point Parser Generator
+// Copyright (c) Wayne Kelly, QUT 2005-2010
+// (see accompanying GPPGcopyright.rtf)
+
+using System;
+using System.Text;
+using System.Globalization;
+using System.Collections.Generic;
+using System.Runtime.Serialization;
+using System.Diagnostics.CodeAnalysis;
+
+namespace QUT.Gppg {
+    /// <summary>
+    /// Abstract class for GPPG shift-reduce parsers.
+    /// Parsers generated by GPPG derive from this base
+    /// class, overriding the abstract Initialize() and
+    /// DoAction() methods.
+    /// </summary>
+    /// <typeparam name="TValue">Semantic value type</typeparam>
+    /// <typeparam name="TSpan">Location type</typeparam>
+#if EXPORT_GPPG
+    public abstract class ShiftReduceParser<TValue, TSpan>
+#else
+    internal abstract class ShiftReduceParser<TValue, TSpan>
+#endif
+ where TSpan : IMerge<TSpan>, new() {
+        private AbstractScanner<TValue, TSpan> scanner;
+        /// <summary>
+        /// The abstract scanner for this parser.
+        /// </summary>
+        protected AbstractScanner<TValue, TSpan> Scanner {
+            get { return scanner; }
+            set { scanner = value; }
+        }
+
+        /// <summary>
+        /// Constructor for base class
+        /// </summary>
+        /// <param name="scanner">Scanner instance for this parser</param>
+        protected ShiftReduceParser( AbstractScanner<TValue, TSpan> scanner ) {
+            this.scanner = scanner;
+        }
+
+        // ==============================================================
+        //                    TECHNICAL EXPLANATION.
+        //   Why the next two fields are not exposed via properties.
+        // ==============================================================
+        // These fields are of the generic parameter types, and are
+        // frequently instantiated as struct types in derived classes.
+        // Semantic actions are defined in the derived classes and refer
+        // to instance fields of these structs.  In such cases the code
+        // "get_CurrentSemanticValue().myField = blah;" will fail since
+        // the getter pushes the value of the field, not the reference.
+        // So, in the presence of properties, gppg would need to encode
+        // such field accesses as ... 
+        //  "tmp = get_CurrentSemanticValue(); // Fetch value
+        //   tmp.myField = blah;               // update
+        //   set_CurrentSemanticValue(tmp); "  // Write update back.
+        // There is no issue if TValue is restricted to be a ref type.
+        // The same explanation applies to scanner.yylval.
+        // ==============================================================
+        /// <summary>
+        /// The current value of the "$$" symbolic variable in the parser
+        /// </summary>
+        [SuppressMessage( "Microsoft.Design", "CA1051:DoNotDeclareVisibleInstanceFields" )]
+        protected TValue CurrentSemanticValue;
+
+        /// <summary>
+        /// The current value of the "@$" symbolic variable in the parser
+        /// </summary>
+        [SuppressMessage( "Microsoft.Design", "CA1051:DoNotDeclareVisibleInstanceFields" )]
+        protected TSpan CurrentLocationSpan;
+        protected int NextToken;
+
+        private TSpan LastSpan;
+        private State FsaState;
+        private bool recovering;
+        private int tokensSinceLastError;
+
+        private PushdownPrefixState<State> StateStack = new PushdownPrefixState<State>();
+        private PushdownPrefixState<TValue> valueStack = new PushdownPrefixState<TValue>();
+        private PushdownPrefixState<TSpan> locationStack = new PushdownPrefixState<TSpan>();
+
+        /// <summary>
+        /// The stack of semantic value (YYSTYPE) values.
+        /// </summary>
+        protected PushdownPrefixState<TValue> ValueStack { get { return valueStack; } }
+
+        /// <summary>
+        /// The stack of location value (YYLTYPE) varlues.
+        /// </summary>
+        protected PushdownPrefixState<TSpan> LocationStack { get { return locationStack; } }
+
+        private int errorToken;
+        private int endOfFileToken;
+        private string[] nonTerminals;
+        private State[] states;
+        private Rule[] rules;
+
+        /// <summary>
+        /// Initialization method to allow derived classes
+        /// to insert the rule list into this base class.
+        /// </summary>
+        /// <param name="rules">The array of Rule objects</param>
+        protected void InitRules( Rule[] rules ) { this.rules = rules; }
+
+        /// <summary>
+        /// Initialization method to allow derived classes to
+        /// insert the states table into this base class.
+        /// </summary>
+        /// <param name="states">The pre-initialized states table</param>
+        protected void InitStates( State[] states ) { this.states = states; }
+
+        /// <summary>
+        /// OBSOLETE FOR VERSION 1.4.0
+        /// </summary>
+        /// <param name="size"></param>
+        protected void InitStateTable( int size ) { states = new State[size]; }
+
+        /// <summary>
+        /// Initialization method to allow derived classes
+        /// to insert the special value for the error and EOF tokens.
+        /// </summary>
+        /// <param name="err">The error state ordinal</param>
+        /// <param name="end">The EOF stat ordinal</param>
+        protected void InitSpecialTokens( int err, int end ) {
+            errorToken = err;
+            endOfFileToken = end;
+        }
+
+        /// <summary>
+        /// Initialization method to allow derived classes to
+        /// insert the non-terminal symbol names into this base class.
+        /// </summary>
+        /// <param name="names">Non-terminal symbol names</param>
+        protected void InitNonTerminals( string[] names ) { nonTerminals = names; }
+
+        #region YYAbort, YYAccept etcetera.
+        [Serializable]
+        [SuppressMessage( "Microsoft.Design", "CA1064:ExceptionsShouldBePublic" )]
+        // Reason for FxCop message suppression -
+        // This exception cannot escape from the local context
+        private class AcceptException : Exception {
+            internal AcceptException() { }
+            protected AcceptException( SerializationInfo i, StreamingContext c ) : base( i, c ) { }
+        }
+        [Serializable]
+        [SuppressMessage( "Microsoft.Design", "CA1064:ExceptionsShouldBePublic" )]
+        // Reason for FxCop message suppression -
+        // This exception cannot escape from the local context
+        private class AbortException : Exception {
+            internal AbortException() { }
+            protected AbortException( SerializationInfo i, StreamingContext c ) : base( i, c ) { }
+        }
+        [Serializable]
+        [SuppressMessage( "Microsoft.Design", "CA1064:ExceptionsShouldBePublic" )]
+        // Reason for FxCop message suppression -
+        // This exception cannot escape from the local context
+        private class ErrorException : Exception {
+            internal ErrorException() { }
+            protected ErrorException( SerializationInfo i, StreamingContext c ) : base( i, c ) { }
+        }
+
+        // The following methods are only called from within
+        // a semantic action. The thrown exceptions can never
+        // propagate outside the ShiftReduceParser class in 
+        // which they are nested.
+
+        /// <summary>
+        /// Force parser to terminate, returning "true"
+        /// </summary>
+        protected static void YYAccept() { throw new AcceptException(); }
+
+        /// <summary>
+        /// Force parser to terminate, returning "false"
+        /// </summary>
+        protected static void YYAbort() { throw new AbortException(); }
+
+        /// <summary>
+        /// Force parser to terminate, returning
+        /// "false" if error recovery fails.
+        /// </summary>
+        protected static void YYError() { throw new ErrorException(); }
+
+        /// <summary>
+        /// Check if parser in error recovery state.
+        /// </summary>
+        protected bool YYRecovering { get { return recovering; } }
+        #endregion
+
+        /// <summary>
+        /// Abstract base method. ShiftReduceParser calls this
+        /// to initialize the base class data structures.  Concrete
+        /// parser classes must override this method.
+        /// </summary>
+        protected abstract void Initialize();
+
+        /// <summary>
+        /// Main entry point of the Shift-Reduce Parser.
+        /// </summary>
+        /// <returns>True if parse succeeds, else false for
+        /// unrecoverable errors</returns>
+        public bool Parse() {
+            Initialize();	// allow derived classes to instantiate rules, states and nonTerminals
+
+            NextToken = 0;
+            FsaState = states[0];
+
+            StateStack.Push( FsaState );
+            valueStack.Push( CurrentSemanticValue );
+            LocationStack.Push( CurrentLocationSpan );
+
+            while (true) {
+#if TRACE_ACTIONS
+                Console.Error.WriteLine("Entering state {0} ", FsaState.number);
+                DisplayStack();
+#endif
+                int action = FsaState.defaultAction;
+
+                if (FsaState.ParserTable != null) {
+                    if (NextToken == 0) {
+                        // We save the last token span, so that the location span
+                        // of production right hand sides that begin or end with a
+                        // nullable production will be correct.
+                        LastSpan = scanner.yylloc;
+                        NextToken = scanner.yylex();
+#if TRACE_ACTIONS
+                       Console.Error.WriteLine( "Reading: Next token is {0}", TerminalToString( NextToken ) );
+#endif
+                    }
+#if TRACE_ACTIONS
+                    else 
+                        Console.Error.WriteLine( "Next token is still {0}", TerminalToString( NextToken ) );
+#endif
+                    if (FsaState.ParserTable.ContainsKey( NextToken ))
+                        action = FsaState.ParserTable[NextToken];
+                }
+
+                if (action > 0)         // shift
+                {
+                    Shift( action );
+                }
+                else if (action < 0)   // reduce
+                {
+                    try {
+                        Reduce( -action );
+                        if (action == -1)	// accept
+                            return true;
+                    }
+                    catch (AbortException) {
+                            return false;
+                    }
+                    catch (AcceptException) {
+                        return true;
+                    }
+                    catch (ErrorException) {
+                        if (!ErrorRecovery())
+                            return false;
+                        else
+                            throw;  // Rethrow x, preserving information.
+                    }
+                }
+                else if (action == 0 && !ErrorRecovery()) // error
+                    return false;
+            }
+        }
+
+        private void Shift( int stateIndex ) {
+#if TRACE_ACTIONS
+				Console.Error.Write("Shifting token {0}, ", TerminalToString(NextToken));
+#endif
+            FsaState = states[stateIndex];
+
+            valueStack.Push( scanner.yylval );
+            StateStack.Push( FsaState );
+            LocationStack.Push( scanner.yylloc );
+
+            if (recovering) {
+                if (NextToken != errorToken)
+                    tokensSinceLastError++;
+
+                if (tokensSinceLastError > 5)
+                    recovering = false;
+            }
+
+            if (NextToken != endOfFileToken)
+                NextToken = 0;
+        }
+
+        private void Reduce( int ruleNumber ) {
+#if TRACE_ACTIONS
+				DisplayRule(ruleNumber);
+#endif
+            Rule rule = rules[ruleNumber];
+            int rhLen = rule.RightHandSide.Length;
+            //
+            //  Default actions for unit productions.
+            //
+            if (rhLen == 1) {
+                CurrentSemanticValue = valueStack.TopElement();   // Default action: $$ = $1;
+                CurrentLocationSpan = LocationStack.TopElement(); // Default action "@$ = @1;
+            }
+            else if (rhLen == 0) {
+                // Create a new blank value.
+                // Explicit semantic action may mutate this value
+                CurrentSemanticValue = default( TValue );
+                // The location span for an empty production will start with the
+                // beginning of the next lexeme, and end with the finish of the
+                // previous lexeme.  This gives the correct behaviour when this
+                // nonsense value is used in later Merge operations.
+                CurrentLocationSpan = (scanner.yylloc != null && LastSpan != null ?
+                    scanner.yylloc.Merge( LastSpan ) :
+                    default( TSpan ));
+            }
+            else {
+                // Default action: $$ = $1;
+                CurrentSemanticValue = valueStack[LocationStack.Depth - rhLen];
+                //  Default action "@$ = @1.Merge(@N)" for location info.
+                TSpan at1 = LocationStack[LocationStack.Depth - rhLen];
+                TSpan atN = LocationStack[LocationStack.Depth - 1];
+                CurrentLocationSpan =
+                    ((at1 != null && atN != null) ? at1.Merge( atN ) : default( TSpan ));
+            }
+
+            DoAction( ruleNumber );
+
+            for (int i = 0; i < rule.RightHandSide.Length; i++) {
+                StateStack.Pop();
+                valueStack.Pop();
+                LocationStack.Pop();
+            }
+            FsaState = StateStack.TopElement();
+
+            if (FsaState.Goto.ContainsKey( rule.LeftHandSide ))
+                FsaState = states[FsaState.Goto[rule.LeftHandSide]];
+
+            StateStack.Push( FsaState );
+            valueStack.Push( CurrentSemanticValue );
+            LocationStack.Push( CurrentLocationSpan );
+        }
+
+        /// <summary>
+        /// Execute the selected action from array.
+        /// Must be overriden in derived classes.
+        /// </summary>
+        /// <param name="actionNumber">Index of the action to perform</param>
+        protected abstract void DoAction( int actionNumber );
+
+        private bool ErrorRecovery() {
+            bool discard;
+
+            if (!recovering) // if not recovering from previous error
+                ReportError();
+
+            if (!FindErrorRecoveryState())
+                return false;
+            //
+            //  The interim fix for the "looping in error recovery"
+            //  artifact involved moving the setting of the recovering 
+            //  bool until after invalid tokens have been discarded.
+            //
+            ShiftErrorToken();
+            discard = DiscardInvalidTokens();
+            recovering = true;
+            tokensSinceLastError = 0;
+            return discard;
+        }
+
+        private void ReportError() {
+            StringBuilder errorMsg = new StringBuilder();
+            errorMsg.AppendFormat( "Syntax error, unexpected {0}", TerminalToString( NextToken ) );
+
+            if (FsaState.ParserTable.Count < 7) {
+                bool first = true;
+                foreach (int terminal in FsaState.ParserTable.Keys) {
+                    if (first)
+                        errorMsg.Append( ", expecting " );
+                    else
+                        errorMsg.Append( ", or " );
+
+                    errorMsg.Append( TerminalToString( terminal ) );
+                    first = false;
+                }
+            }
+            scanner.yyerror( errorMsg.ToString() );
+        }
+
+        private void ShiftErrorToken() {
+            int old_next = NextToken;
+            NextToken = errorToken;
+
+            Shift( FsaState.ParserTable[NextToken] );
+
+#if TRACE_ACTIONS
+				Console.Error.WriteLine("Entering state {0} ", FsaState.number);
+#endif
+            NextToken = old_next;
+        }
+
+        private bool FindErrorRecoveryState() {
+            while (true)    // pop states until one found that accepts error token
+            {
+                if (FsaState.ParserTable != null &&
+                    FsaState.ParserTable.ContainsKey( errorToken ) &&
+                    FsaState.ParserTable[errorToken] > 0) // shift
+                    return true;
+
+#if TRACE_ACTIONS
+					Console.Error.WriteLine("Error: popping state {0}", StateStack.TopElement().number);
+#endif
+                StateStack.Pop();
+                valueStack.Pop();
+                LocationStack.Pop();
+
+#if TRACE_ACTIONS
+			    DisplayStack();
+#endif
+                if (StateStack.IsEmpty()) {
+#if TRACE_ACTIONS
+                        Console.Error.WriteLine("Aborting: didn't find a state that accepts error token");
+#endif
+                    return false;
+                }
+                else
+                    FsaState = StateStack.TopElement();
+            }
+        }
+
+        private bool DiscardInvalidTokens() {
+
+            int action = FsaState.defaultAction;
+
+            if (FsaState.ParserTable != null) {
+                // Discard tokens until find one that works ...
+                while (true) {
+                    if (NextToken == 0) {
+#if TRACE_ACTIONS
+                            Console.Error.Write("Reading a token: ");
+#endif
+                        NextToken = scanner.yylex();
+                    }
+#if TRACE_ACTIONS
+                        Console.Error.WriteLine("Next token is {0}", TerminalToString(NextToken));
+#endif
+                    if (NextToken == endOfFileToken)
+                        return false;
+
+                    if (FsaState.ParserTable.ContainsKey( NextToken ))
+                        action = FsaState.ParserTable[NextToken];
+
+                    if (action != 0)
+                        return true;
+                    else {
+#if TRACE_ACTIONS
+                            Console.Error.WriteLine("Error: Discarding {0}", TerminalToString(NextToken));
+#endif
+                        NextToken = 0;
+                    }
+                }
+            }
+            else if (recovering && tokensSinceLastError == 0) {
+                // 
+                //  Boolean recovering is not set until after the first
+                //  error token has been shifted.  Thus if we get back 
+                //  here with recovering set and no tokens read we are
+                //  looping on the same error recovery action.  This 
+                //  happens if current_state.ParserTable is null because
+                //  the state has an LR(0) reduction, but not all
+                //  lookahead tokens are valid.  This only occurs for
+                //  error productions that *end* on "error".
+                //
+                //  This action discards tokens one at a time until
+                //  the looping stops.  Another attack would be to always
+                //  use the LALR(1) table if a production ends on "error"
+                //
+#if TRACE_ACTIONS
+                    Console.Error.WriteLine("Error: panic discard of {0}", TerminalToString(NextToken));
+#endif
+                if (NextToken == endOfFileToken)
+                    return false;
+                NextToken = 0;
+                return true;
+            }
+            else
+                return true;
+        }
+
+        /// <summary>
+        /// Traditional YACC method.  Discards the next input token.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yyclearin" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yyclearin" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        protected void yyclearin() { NextToken = 0; }
+
+        /// <summary>
+        /// Tradional YACC method. Clear the "recovering" flag.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yyerrok" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yyerrok" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        protected void yyerrok() { recovering = false; }
+
+        /// <summary>
+        /// OBSOLETE FOR VERSION 1.4.0
+        /// Method used by derived types to insert new
+        /// state instances in the "states" array.
+        /// </summary>
+        /// <param name="stateNumber">index of the state</param>
+        /// <param name="state">data for the state</param>
+        protected void AddState( int stateNumber, State state ) {
+            states[stateNumber] = state;
+            state.number = stateNumber;
+        }
+
+        private void DisplayStack() {
+            Console.Error.Write( "State stack is now:" );
+            for (int i = 0; i < StateStack.Depth; i++)
+                Console.Error.Write( " {0}", StateStack[i].number );
+            Console.Error.WriteLine();
+        }
+
+        private void DisplayRule( int ruleNumber ) {
+            Console.Error.Write( "Reducing stack by rule {0}, ", ruleNumber );
+            DisplayProduction( rules[ruleNumber] );
+        }
+
+        private void DisplayProduction( Rule rule ) {
+            if (rule.RightHandSide.Length == 0)
+                Console.Error.Write( "/* empty */ " );
+            else
+                foreach (int symbol in rule.RightHandSide)
+                    Console.Error.Write( "{0} ", SymbolToString( symbol ) );
+
+            Console.Error.WriteLine( "-> {0}", SymbolToString( rule.LeftHandSide ) );
+        }
+
+        /// <summary>
+        /// Abstract state class naming terminal symbols.
+        /// This is overridden by derived classes with the
+        /// name (or alias) to be used in error messages.
+        /// </summary>
+        /// <param name="terminal">The terminal ordinal</param>
+        /// <returns></returns>
+        protected abstract string TerminalToString( int terminal );
+
+        private string SymbolToString( int symbol ) {
+            if (symbol < 0)
+                return nonTerminals[-symbol - 1];
+            else
+                return TerminalToString( symbol );
+        }
+
+        /// <summary>
+        /// Return text representation of argument character
+        /// </summary>
+        /// <param name="input">The character to convert</param>
+        /// <returns>String representation of the character</returns>
+        protected static string CharToString( char input ) {
+            switch (input) {
+                case '\a': return @"'\a'";
+                case '\b': return @"'\b'";
+                case '\f': return @"'\f'";
+                case '\n': return @"'\n'";
+                case '\r': return @"'\r'";
+                case '\t': return @"'\t'";
+                case '\v': return @"'\v'";
+                case '\0': return @"'\0'";
+                default: return string.Format( CultureInfo.InvariantCulture, "'{0}'", input );
+            }
+        }
+    }
+
+    /// <summary>
+    /// Classes implementing this interface must supply a
+    /// method that merges two location objects to return
+    /// a new object of the same type.
+    /// GPPG-generated parsers have the default location
+    /// action equivalent to "@$ = @1.Merge(@N);" where N
+    /// is the right-hand-side length of the production.
+    /// </summary>
+    /// <typeparam name="TSpan">The Location type</typeparam>
+#if EXPORT_GPPG
+    public interface IMerge<TSpan>
+#else
+    internal interface IMerge<TSpan>
+#endif
+ {
+        /// <summary>
+        /// Interface method that creates a location object from
+        /// the current and last object.  Typically used to create
+        /// a location object extending from the start of the @1
+        /// object to the end of the @N object.
+        /// </summary>
+        /// <param name="last">The lexically last object to merge</param>
+        /// <returns>The merged location object</returns>
+        TSpan Merge( TSpan last );
+    }
+
+    /// <summary>
+    /// This is the default class that carries location
+    /// information from the scanner to the parser.
+    /// If you don't declare "%YYLTYPE Foo" the parser
+    /// will expect to deal with this type.
+    /// </summary>
+#if EXPORT_GPPG
+    public class LexLocation : IMerge<LexLocation>
+#else
+    [SuppressMessage( "Microsoft.Performance", "CA1812:AvoidUninstantiatedInternalClasses" )]
+    internal class LexLocation : IMerge<LexLocation>
+#endif
+ {
+        private int startLine;   // start line
+        private int startColumn; // start column
+        private int endLine;     // end line
+        private int endColumn;   // end column
+
+        /// <summary>
+        /// The line at which the text span starts.
+        /// </summary>
+        public int StartLine { get { return startLine; } }
+
+        /// <summary>
+        /// The column at which the text span starts.
+        /// </summary>
+        public int StartColumn { get { return startColumn; } }
+
+        /// <summary>
+        /// The line on which the text span ends.
+        /// </summary>
+        public int EndLine { get { return endLine; } }
+
+        /// <summary>
+        /// The column of the first character
+        /// beyond the end of the text span.
+        /// </summary>
+        public int EndColumn { get { return endColumn; } }
+
+        /// <summary>
+        /// Default no-arg constructor.
+        /// </summary>
+        public LexLocation() { }
+
+        /// <summary>
+        /// Constructor for text-span with given start and end.
+        /// </summary>
+        /// <param name="sl">start line</param>
+        /// <param name="sc">start column</param>
+        /// <param name="el">end line </param>
+        /// <param name="ec">end column</param>
+        public LexLocation( int sl, int sc, int el, int ec ) { startLine = sl; startColumn = sc; endLine = el; endColumn = ec; }
+
+        /// <summary>
+        /// Create a text location which spans from the 
+        /// start of "this" to the end of the argument "last"
+        /// </summary>
+        /// <param name="last">The last location in the result span</param>
+        /// <returns>The merged span</returns>
+        public LexLocation Merge( LexLocation last ) { return new LexLocation( this.startLine, this.startColumn, last.endLine, last.endColumn ); }
+    }
+
+    /// <summary>
+    /// Abstract scanner class that GPPG expects its scanners to 
+    /// extend.
+    /// </summary>
+    /// <typeparam name="TValue">Semantic value type YYSTYPE</typeparam>
+    /// <typeparam name="TSpan">Source location type YYLTYPE</typeparam>
+#if EXPORT_GPPG
+    public abstract class AbstractScanner<TValue, TSpan>
+#else
+    internal abstract class AbstractScanner<TValue, TSpan>
+#endif
+ where TSpan : IMerge<TSpan> {
+        /// <summary>
+        /// Lexical value optionally set by the scanner. The value
+        /// is of the %YYSTYPE type declared in the parser spec.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Design", "CA1051:DoNotDeclareVisibleInstanceFields" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yylval" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yylval" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        // A field must be declared for this value of parametric type,
+        // since it may be instantiated by a value struct.  If it were 
+        // implemented as a property, machine generated code in derived
+        // types would not be able to select on the returned value.
+#pragma warning disable 649
+        public TValue yylval;                     // Lexical value: set by scanner
+#pragma warning restore 649
+
+        /// <summary>
+        /// Current scanner location property. The value is of the
+        /// type declared by %YYLTYPE in the parser specification.
+        /// </summary>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yylloc" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yylloc" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        public virtual TSpan yylloc {
+            get { return default( TSpan ); }       // Empty implementation allowing
+            set { /* skip */ }                   // yylloc to be ignored entirely.
+        }
+
+        /// <summary>
+        /// Main call point for LEX-like scanners.  Returns an int
+        /// corresponding to the token recognized by the scanner.
+        /// </summary>
+        /// <returns>An int corresponding to the token</returns>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yylex" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yylex" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        public abstract int yylex();
+
+        /// <summary>
+        /// Traditional error reporting provided by LEX-like scanners
+        /// to their YACC-like clients.
+        /// </summary>
+        /// <param name="format">Message format string</param>
+        /// <param name="args">Optional array of args</param>
+        [SuppressMessage( "Microsoft.Naming", "CA1709:IdentifiersShouldBeCasedCorrectly", MessageId = "yyerror" )]
+        [SuppressMessage( "Microsoft.Naming", "CA1704:IdentifiersShouldBeSpelledCorrectly", MessageId = "yyerror" )]
+        // Reason for FxCop message suppression -
+        // This is a traditional name for YACC-like functionality
+        public virtual void yyerror( string format, params object[] args ) { }
+    }
+
+    /// <summary>
+    /// Encapsulated state for the parser.
+    /// Opaque to users, visible to the tool-generated code.
+    /// </summary>
+#if EXPORT_GPPG
+    public class State
+    {
+        /// <summary>
+        /// The number of states in the automaton.
+        /// </summary>
+        public int number;
+#else
+    internal class State {
+        /// <summary>
+        /// The index of this state in the states array.
+        /// </summary>
+        internal int number;
+#endif
+        internal Dictionary<int, int> ParserTable;   // Terminal -> ParseAction
+        internal Dictionary<int, int> Goto;          // NonTerminal -> State;
+        internal int defaultAction; // = 0;		     // ParseAction
+
+        /// <summary>
+        /// State transition data for this state. Pairs of elements of the 
+        /// goto array associate symbol ordinals with next state indices.
+        /// The actions array is passed to another constructor. 
+        /// </summary>
+        /// <param name="actions">The action list</param>c
+        /// <param name="goToList">Next state data</param>
+        public State( int[] actions, int[] goToList )
+            : this( actions ) {
+            Goto = new Dictionary<int, int>();
+            for (int i = 0; i < goToList.Length; i += 2)
+                Goto.Add( goToList[i], goToList[i + 1] );
+        }
+
+        /// <summary>
+        /// Action data for this state. Pairs of elements of the 
+        /// action array associate action ordinals with each of
+        /// those symbols that have actions in the current state.
+        /// </summary>
+        /// <param name="actions">The action array</param>
+        public State( int[] actions ) {
+            ParserTable = new Dictionary<int, int>();
+            for (int i = 0; i < actions.Length; i += 2)
+                ParserTable.Add( actions[i], actions[i + 1] );
+        }
+
+        /// <summary>
+        /// Set the default action for this state.
+        /// </summary>
+        /// <param name="defaultAction">Ordinal of the default action</param>
+        public State( int defaultAction ) {
+            this.defaultAction = defaultAction;
+        }
+
+        /// <summary>
+        /// Set the default action and the state transition table.
+        /// </summary>
+        /// <param name="defaultAction">The default action</param>
+        /// <param name="goToList">Transitions from this state</param>
+        public State( int defaultAction, int[] goToList )
+            : this( defaultAction ) {
+            Goto = new Dictionary<int, int>();
+            for (int i = 0; i < goToList.Length; i += 2)
+                Goto.Add( goToList[i], goToList[i + 1] );
+        }
+    }
+
+    /// <summary>
+    /// Rule representation at runtime.
+    /// </summary>
+#if EXPORT_GPPG
+    public class Rule
+#else
+    internal class Rule
+#endif
+ {
+        internal int LeftHandSide; // symbol
+        internal int[] RightHandSide; // symbols
+
+        /// <summary>
+        /// Rule constructor.  This holds the ordinal of
+        /// the left hand side symbol, and the list of
+        /// right hand side symbols, in lexical order.
+        /// </summary>
+        /// <param name="left">The LHS non-terminal</param>
+        /// <param name="right">The RHS symbols, in lexical order</param>
+        public Rule( int left, int[] right ) {
+            this.LeftHandSide = left;
+            this.RightHandSide = right;
+        }
+    }
+
+    /// <summary>
+    /// Stack utility for the shift-reduce parser.
+    /// GPPG parsers have three instances:
+    /// (1) The parser state stack, T = QUT.Gppg.State,
+    /// (2) The semantic value stack, T = TValue,
+    /// (3) The location stack, T = TSpan.
+    /// </summary>
+    /// <typeparam name="T"></typeparam>
+#if EXPORT_GPPG
+    public class PushdownPrefixState<T>
+#else
+    internal class PushdownPrefixState<T>
+#endif
+ {
+        //  Note that we cannot use the BCL Stack<T> class
+        //  here as derived types need to index into stacks.
+        //
+        private T[] array = new T[8];
+        private int tos = 0;
+
+        /// <summary>
+        /// Indexer for values of the stack below the top.
+        /// </summary>
+        /// <param name="index">index of the element, starting from the bottom</param>
+        /// <returns>the selected element</returns>
+        public T this[int index] { get { return array[index]; } }
+
+        /// <summary>
+        /// The current depth of the stack.
+        /// </summary>
+        public int Depth { get { return tos; } }
+
+        internal void Push( T value ) {
+            if (tos >= array.Length) {
+                T[] newarray = new T[array.Length * 2];
+                System.Array.Copy( array, newarray, tos );
+                array = newarray;
+            }
+            array[tos++] = value;
+        }
+
+        internal T Pop() {
+            T rslt = array[--tos];
+            array[tos] = default( T );
+            return rslt;
+        }
+
+        internal T TopElement() { return array[tos - 1]; }
+
+        internal bool IsEmpty() { return tos == 0; }
+    }
+}
+

src/DataStreamSuite/Bts.ColumnSortExpressions/Usings.cs

@@ -0,0 +1,4 @@
+global using System;
+global using System.Linq;
+global using System.Collections.Generic;
+global using System.Collections.Immutable;

src/DataStreamSuite/ColumnMapExpressions/ColumnMapExpressions.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Google.Protobuf" Version="3.24.3" />
-    <PackageReference Include="YaccLexTools" Version="1.2.0" />
+    <PackageReference Include="YaccLexTools" Version="1.2.2" />
   </ItemGroup>
 
   <ItemGroup>

src/DataStreamSuite/DataStream/DataStream.csproj

@@ -7,11 +7,19 @@
 
   <ItemGroup>
     <ProjectReference Include="..\ArithmeticExpressions\ArithmeticExpressions.csproj" />
-    <ProjectReference Include="..\BaseUtilities\BaseUtilities.csproj" />
+    <ProjectReference Include="..\BaseUtilities\BaseUtilities.csproj" />    
     <ProjectReference Include="..\BooleanExpressions\BooleanExpressions.csproj" />
+    <ProjectReference Include="..\Bts.ColumnExpressions\Bts.ColumnExpressions.csproj" />
+    <ProjectReference Include="..\Bts.ColumnSortExpressions\Bts.ColumnSortExpressions.csproj" />
     <ProjectReference Include="..\DataStreamCore\DataStreamCore.csproj" />
     <ProjectReference Include="..\DataStreamExpressions\DataStreamExpressions.csproj" />
     <ProjectReference Include="..\..\client\spark_core\spark_core.csproj" />
   </ItemGroup>
 
+  <ItemGroup>
+    <PackageReference Include="HtmlAgilityPack" Version="1.11.57" />
+    <PackageReference Include="MongoDB.Bson" Version="2.23.1" />
+    <PackageReference Include="MongoDB.Driver" Version="2.23.1" />
+  </ItemGroup>
+
 </Project>

src/DataStreamSuite/DataStream/Misc/PandasStream.cs

@@ -0,0 +1,62 @@
+// using System;
+// using System.Diagnostics;
+
+// using BCG;
+// using BCG.Utilities.General;
+
+
+// namespace bts {
+
+//     public class PandasStream : ViewStream, IWorker {
+//         //C:\Users\Owner\AppData\Local\Microsoft\WindowsApps\python.exe
+
+//         public PandasStream(ViewStream vs, ViewStreamDatabase vsd, string pandas_code) {
+
+//         }
+
+//         public PandasStream(ViewStream vs, string pandas_code) :
+//         this(vs, ViewStreamDatabase.instance, pandas_code) {
+//         }
+
+
+//         protected override void myOnFirstSubscriber() {
+
+//             // string python_code = @"
+//             //    import winsound
+//             //    frequency = 2500  # Set frequency (in Hz)
+//             //    duration = 1000   # Set duration (in milliseconds)
+//             //    winsound.Beep(frequency, duration)
+//             // ";
+//             string python_code = @"
+//             file_path = \"C:\\Temp\\test2.txt\\"  # r prefix for raw string to avoid escape characters
+//             with open(file_path, \"w\") as f:
+//                 f.write(\"Hello, world!\n\")
+//             ";
+
+//             execute_python_code(python_code);
+//         }
+
+//         static void execute_python_code(string python_code) {
+//             ProcessStartInfo start = new ProcessStartInfo();
+//             start.FileName = "python"; // Python executable
+//             start.Arguments = "-c \"" + python_code.Replace("\"", "\\\"") + "\""; // Pass code as argument
+//             start.UseShellExecute = false;
+//             start.RedirectStandardOutput = true;
+
+//             using (Process process = Process.Start(start)) {
+//                 using (System.IO.StreamReader reader = process.StandardOutput) {
+//                     string result = reader.ReadToEnd();
+//                     Console.Write(result);
+//                 }
+//             }
+//         }
+
+//         protected override void myOnLastSubscriber() {
+//         }
+
+//         public void doWork() {
+
+//         }
+
+//     }
+// }

src/DataStreamSuite/DataStream/Misc/TCPConnectionTestStream.cs

@@ -0,0 +1,79 @@
+using BCG.Utilities.General;
+
+using System;
+
+namespace BCG {
+    public class TCPConnectionTestStream : ViewStream, IWorker, ITCPConnectionHandler, ITCPMessageHandler {
+        class State {
+            public int n_sends = 0;
+            public int n_recvs = 0;
+        }
+        private readonly string _ip;
+        private readonly int _port;
+        private readonly ViewStreamDatabase _vsd;
+        State _state = new State();
+        private readonly int _msg_size;
+
+        private IBlueTableSchema _schema;
+        private TimeSpan _send_period;
+        private ITCPConnection _connection = null;
+        private byte[] _buff;
+
+        public TCPConnectionTestStream(string ip, int port, int msg_size, int send_period_seconds) :
+        this(ip, port, msg_size, send_period_seconds, ViewStreamDatabase.instance) { }
+        public TCPConnectionTestStream(string ip, int port, int msg_size, int send_period_seconds, ViewStreamDatabase vsd) {
+            _ip = ip;
+            _port = port;
+            _msg_size = msg_size;
+            _vsd = vsd;
+            _schema = BlueDataUtility.form_schema("TCPClient",
+            Tuple.Create("id", TypeCode.Int32),
+            Tuple.Create("n_sends", TypeCode.UInt32),
+            Tuple.Create("n_recvs", TypeCode.UInt32));
+            _send_period = TimeSpan.FromSeconds(send_period_seconds);
+            _buff = new byte[msg_size];
+            for (int i = 0; i < _buff.Length; i++) {
+                _buff[i] = (byte)i;
+            }
+        }
+
+        protected override void myOnFirstSubscriber() {
+            MasterWorker.getInstance(false).addWorker(this, _send_period);
+            var server_address = new BlutoSubAddress(_ip, _port);
+            bts.AsyncTCPConnector_APM.connect_to(server_address, this);
+        }
+
+        protected override void myOnLastSubscriber() {
+            MasterWorker.getInstance(false).removeWorker(this);
+        }
+
+        public void doWork() {
+            if (_connection != null) {
+                _connection.send(_buff);
+                _state.n_sends++;
+            }
+            IBlueRow r = new BlueRow(_schema, 0, _state.n_sends, _state.n_recvs);
+            BlueTable rows = new BlueTable(r.schema);
+            rows.addRow(r);
+            var dp = BlueDataUtility.build_dp_inc(rows, myLastValue as DataPacket, true);
+            myFireEvent(dp);
+        }
+
+        public void onConnection(ITCPConnection connection) {
+            _connection = connection;
+            _connection.register(this);
+        }
+        public bool isDisposed { get; }
+
+        public void onData(RemoteMessage msg) {
+            bts.Log.Gen.info($"TCPConnectionTestStream received msg: {msg}");
+            _state.n_recvs++;
+        }
+
+        public void Dispose() {
+
+        }
+
+
+    }
+}

src/DataStreamSuite/DataStream/Misc/test.py

@@ -0,0 +1,3 @@
+file_path = r"C:\Temp\test2.txt"  # r prefix for raw string to avoid escape characters
+with open(file_path, "w") as f:
+    f.write("Hello, world!\n")

src/DataStreamSuite/DataStream/Offloading/AddToCloudStream.cs

@@ -0,0 +1,32 @@
+using BCG;
+
+namespace BCG
+{
+   // this is a stream so we can run it from the DSQA (since dsqa can only load streams)
+   [DataStreamUserRespresentation("add_to_cloud")]
+   public class AddToCloudStream : ViewStream
+   {
+      private readonly string _name, _stream_exp;
+      private StreamOffloadRequestor _requestor = new StreamOffloadRequestor();
+      public AddToCloudStream(string name, params string[] lines)
+      : this(name, 0, lines)
+      {
+      }
+
+      public AddToCloudStream(string name, int persist, params string[] lines)
+      {
+         _name = name;
+         _stream_exp = getExpression(lines);
+         _requestor.add_to_cloud(_name, _stream_exp, persist == 1);
+         mySetRealSource(new TableStream("cloud_streams"));
+      }
+
+      static string getExpression(params string[] lines) {
+         for (int i = 0; i < lines.Length; i++) {
+            // unescape quotes
+            lines[i] = lines[i].Replace("\\\"", "\"");
+         }
+         return string.Join("\n", lines);
+      }
+   }
+}

src/DataStreamSuite/DataStream/Offloading/CloudStreamManager.cs

@@ -0,0 +1,100 @@
+using BCG;
+
+using System;
+using System.Collections.Generic;
+
+using mbts.config;
+using bts.utils;
+using System.Threading.Tasks;
+using Bts.DataStreamExpressions;
+using System.Collections.Generic;
+using BCG.Utilities.General;
+
+namespace BCG
+{
+   // listens to the requests posted on "cloud_streams" request table, and 
+   // if unfulfilled starts a ViewPubsliher
+   public class CloudStreamManager : IWorker
+   {
+      public class StreamPubUnit
+      {
+         public string name;
+         public string stream_expression;
+         public ViewStream stream;
+         public bool persist;
+         public ViewPublisher view_publisher;
+
+         public StreamPubUnit(string name_, string stream_expression_, ViewStream stream_, bool persist_, ViewPublisher view_publisher_)
+         {
+            name = name_;
+            stream_expression = stream_expression_;
+            stream = stream_;
+            persist = persist_;
+            view_publisher = view_publisher_;
+         }
+      }
+      static ViewStream build_stream(string stream_expression)
+      {
+         try
+         {
+            var exp = DataStreamExpressionsInterpreter.Evaluate(stream_expression);
+            var rv = exp.getView(new Dictionary<string, StatementExpression>(0));
+            return rv;
+
+         }
+         catch (Exception ex)
+         {
+            bts.Log.assert(false, $"Could not build stream: {stream_expression} ex: {ex}");
+            return null;
+         }
+      }
+      private IDictionary<string, StreamPubUnit>
+         _stream_pub_map = new Dictionary<string, StreamPubUnit>();
+      private ViewStream _stream = new TableStream("cloud_streams");
+      private PubTableBroker _broker = new PubTableBroker();
+
+      public CloudStreamManager()
+      {
+         _stream.onChange += _on_str;
+
+      }
+      private void _on_str(object obj)
+      {
+         DataPacket dp = obj as DataPacket;
+         foreach (IBlueRow r in dp.newRows)
+         {
+            string name = r.get<string>("name");
+            bool persist = r.get<bool>("persist");
+            string stream_exp = r.get<string>("stream_exp");
+            if (!_stream_pub_map.ContainsKey(name))
+            {
+               _assign(name, stream_exp, persist);
+            }
+         }
+      }
+
+      private void _assign(string name, string stream_expression, bool persist)
+      {
+         bts.Log.Gen.info($"CloudStreamManager.assign name: {name} stream_expression: {stream_expression}");
+         ViewStream stream = build_stream(stream_expression);
+         _expose_to_ws(name, stream);
+         if (persist)
+         {
+            stream = new PersistorStream(stream, name, "C:\\Temp\\", 1000000);   // 10MBs
+         }
+         ViewPublisher view_pub = new ViewPublisher(name, _broker, stream);
+         StreamPubUnit u = new StreamPubUnit(name, stream_expression, stream, persist, view_pub);
+         _stream_pub_map.Add(name, u);
+      }
+
+      private void _expose_to_ws(string name, ViewStream stream)
+      {
+         // TODO: john
+      }
+
+      public void doWork()
+      {
+
+      }
+   }
+}

src/DataStreamSuite/DataStream/Offloading/StreamOffloadRequestor.cs

@@ -0,0 +1,59 @@
+using BCG;
+
+using System.Linq;
+
+namespace BCG
+{
+   public class StreamOffloadRequestor
+   {
+      public class OffloadOp
+      {
+         string name;
+         string stream_exp;
+      }
+      private IBlueTableSchema _schema;
+      private IBlueRowCollection _rows;
+      private PubTableBroker _broker = new PubTableBroker();
+      ViewStream _existing_offloads_vs = new TableStream("cloud_streams");
+      public StreamOffloadRequestor()
+      {
+         _schema = new BlueTableSchema("cloud_streams",
+                                   new ColumnInfo("id", 0, typeof(int)),
+                                   new ColumnInfo("name", 1, typeof(string)),
+                                   new ColumnInfo("persist", 2, typeof(bool)),
+                                   new ColumnInfo("stream_exp", 3, typeof(string)));
+         _existing_offloads_vs.onChange += _on_str;
+      }
+      private void _on_str(object obj)
+      {
+         DataPacket dp = obj as DataPacket;
+         _rows = dp.newRows;
+         // this is needed so the broker knows the state of the table
+         _broker.createTable(_rows);
+      }
+      public void add_to_cloud(string name, string stream_exp, bool persist)
+      {
+         // check if it exists
+         if (_rows == null)
+         {
+            BlueTable table = new BlueTable(_schema);
+            IBlueRow nr = new BlueRow(_schema, 0, name, persist, stream_exp);
+            table.addRow(nr);
+            _broker.createTable(table);
+            // create table  
+         }
+         else
+         {
+            if (exists(name))
+               return;
+            IBlueRow nr = new BlueRow(_schema, _rows.Count, name, persist, stream_exp);
+            _broker.addRow(nr);
+         }
+      }
+
+      bool exists(string name)
+      {
+         return _rows.to_ienum().Where(r => name == r.get<string>("name")).Count() > 0;
+      }
+   }
+}

src/DataStreamSuite/DataStream/Primitives/AddColumns/AddColumnsStream.cs

@@ -1,13 +1,6 @@
-// using System;
-// using System.Data;
-// using System.Collections;
-// using BCG.Utilities;
-// using BCG.Utilities.General;
-// namespace BCG
-// {
-
-//    public class AddColumnsStream : MapStream
-//    {
-//       public AddColumnsStream(ViewStream vs, string columnDef) : base (vs, new ColumnAdder (columnDef))  {}    
-//    }
-// }
+namespace BCG;
+
+public class AddColumnsStream : MapStream {
+   public AddColumnsStream(ViewStream vs, string columnDef)
+      : base(vs, new ColumnAdder(columnDef)) { }
+}

src/DataStreamSuite/DataStream/Primitives/AddColumns/AddConstantColumnRow.cs

@@ -0,0 +1,12 @@
+namespace bts {
+    using BCG;
+
+    using System;
+    using System.Collections;
+
+    public class AddConstantColumnRow {
+        AddConstantColumnRow(IBlueRow r, Tuple<string, Type, object>[] constant_cols) {
+
+        }
+    }
+}

src/DataStreamSuite/DataStream/Primitives/AddColumns/ColumnAdder.cs

@@ -1,73 +1,52 @@
-// using System;
-// using System.Collections;
-// using BCG.Utilities;
-// using BCG.Evaluator.AddColumnsExpression;
-
-// namespace BCG
-// {
-//    /// <summary>
-//    /// Provides methods to add columns to the schema
-//    /// </summary>
-//    public class ColumnAdder : IStreamMapper
-//    {
-//       protected IDictionary myNewColumns;
-//       protected IBlueTableSchema mySchema;
-
-//       static syntax myParser =
-//          new syntax();
-
-//       /// <summary>
-//       /// string represting the columns to be added to the output table. 
-//       /// </summary>
-//       /// <param name="colAddExpression"></param>
-//       public ColumnAdder (string columnDef)
-//       {
-//          AddColumnsExpression ace;
-
-//          if (DataStreamLoadFileConfig.instance.useStaticParser)
-//          {
-//             lock (myParser)
-//             {
-//                ace =
-//                (AddColumnsExpression)myParser.Parse(columnDef);
-//             }
-//          }
-//          else
-//          {
-//             syntax parser = new syntax();
-//             ace =
-//             (AddColumnsExpression)parser.Parse(columnDef);
-//          }
-
-// 	 if (ace == null)
-// 	   throw new Exception ("Invalid columnn expression: " + columnDef);
-//          myNewColumns = ace.columns;
-//       }
-         
-//       public virtual IBlueRow map (IBlueRow row)
-//       {
-//          if (mySchema == null)
-//             myConstructSchema (row.schema);
-//          return new AddColumnsRow (mySchema, row);
-//       }
-
-//       public IBlueTableSchema getOutputSchema (IBlueTableSchema inputSchema)
-//       {
-//          myConstructSchema (inputSchema);
-//          return mySchema;
-//       }
-
-//       private void myConstructSchema (IBlueTableSchema schema)
-//       {
-//          ColumnInfo[] cis = new ColumnInfo[schema.columnNames.Length + myNewColumns.Count];
-//          int ciIndex = 0;
-//          foreach (ColumnInfo ci in schema.columnInfo)
-//             cis[ciIndex++] = ci;
-//          foreach (DictionaryEntry de in myNewColumns)
-//             cis[ciIndex] = new ColumnInfo ((string)de.Key, ciIndex ++, 
-//                ((AddColumnsExpression.ConstantInfo)de.Value).t, ((AddColumnsExpression.ConstantInfo)de.Value).v);
-//          mySchema = new BlueTableSchema (cis, schema.tableName);
-//       }
-
-//    }
-// }
+using System;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+using System.Linq;
+
+using Bts.ColumnExpressions;
+
+namespace BCG;
+
+/// <summary>
+/// Provides methods to add columns to the schema
+/// </summary>
+/// <param name="columnsExpression">
+/// String represting the columns to add to the output table
+/// </param>
+public class ColumnAdder : IStreamMapper {
+   // Store tuples of (column, index) to preserve order
+   protected readonly IDictionary<string, (ColumnExpression column, int index)> myNewColumns;
+   protected IBlueTableSchema? mySchema;
+
+   public ColumnAdder(string columnsExpression) =>
+      myNewColumns = (ColumnExpressionInterpreter.Evaluate(columnsExpression) ??
+         throw new Exception("Invalid columnn expression: " + columnsExpression))
+         .Select((c, i) => (c, i))
+         .ToDictionary(c => c.c.Name, c => (c.c, c.i));
+
+   [MemberNotNull(nameof(mySchema))]
+   public virtual IBlueRow map(IBlueRow row) {
+      // Only rebuild schema if necessary (i.e., if it's null)
+      mySchema ??= buildSchema(row.schema, myNewColumns);
+      return new AddColumnsRow(mySchema, row);
+   }
+
+   [MemberNotNull(nameof(mySchema))]
+   public IBlueTableSchema getOutputSchema(IBlueTableSchema inputSchema) =>
+      // Always rebuild schema (even if it's already non-null)
+      mySchema = buildSchema(inputSchema, myNewColumns);
+
+   [MemberNotNull(nameof(mySchema))]
+   static BlueTableSchema buildSchema(
+      IBlueTableSchema schema,
+      IDictionary<string, (ColumnExpression column, int index)> newColumns
+   ) {
+      ColumnInfo[] cis = new ColumnInfo[schema.columnNames.Length + newColumns.Count];
+      schema.columnInfo.CopyTo(cis, 0);
+      foreach (var (col, index) in newColumns.Values) {
+         var schemaIdx = schema.columnInfo.Length + index;
+         cis[schemaIdx] = new ColumnInfo(col.Name, schemaIdx, col.Type, col.Value);
+      }
+      return new BlueTableSchema(cis, schema.tableName);
+   }
+}

src/DataStreamSuite/DataStream/Primitives/FileStreams/CaptureSnapshotStream.cs

@@ -1,40 +0,0 @@
-// using System;
-// using System.Collections.Generic;
-// using System.Linq;
-// using System.Text;
-// using System.IO;
-
-// namespace BCG
-// {
-//    public class CaptureSnapshotStream : ViewStream
-//    {
-//       public CaptureSnapshotStream(string basePath,ViewStream sourceStream)
-//       {
-//          myBasePath = basePath;
-//          mySource = sourceStream;
-//          Directory.CreateDirectory(myBasePath);
-//       }
-
-//       protected override void myOnFirstSubscriber()
-//       {
-//          mySource.onChange += new ChangeDelegate(mySource_onChange);
-//       }
-
-//       protected override void myOnLastSubscriber()
-//       {
-//          mySource.onChange -= mySource_onChange;
-//       }
-
-//       void mySource_onChange(object newValue)
-//       {
-//          DateTime now = DateTime.Now;
-//          new ViewStreamWaiter(new SaverStream(new BlueRowCollectionStaticStream(((DataPacket)newValue).newRows),
-//              Path.Combine(myBasePath, String.Format("{0}_{1}.ds", now.ToString("yyyyMMdd_HHmmss"),
-//              now.Millisecond)))).waitUntilArrived();
-//          myFireEvent(newValue);
-//       }
-
-//       private string myBasePath;
-//       private ViewStream mySource;
-//    }
-// }

src/DataStreamSuite/DataStream/Primitives/FileStreams/PersistorStream.cs

@@ -0,0 +1,135 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.IO;
+using Google.Protobuf;
+using System.Globalization;
+
+namespace BCG {
+   // Writes all the udpates to a stream in a file.
+   // File naming:
+   // token_epoch_yyyyMMdd_HHmmss
+   // File location: directory(passed)\token\
+   // directory passed on, it creates a folder with the token passed
+   // data:
+   // epochtime, size, serialized data
+   [DataStreamUserRespresentation("pers")]
+   // Saves each udpate of a stream into a file. The token is the the unique logical name of the stream,
+   // which maps the name of the directory where the streams are saved. The directory (3rd arg) is the 
+   // parent directory where the token folder is stored. Each file goes up to rolloevr_size after which a new
+   // file is created. The file names are token_epoch_datetime
+   // the first entry in a file is the complete state
+   public class PersistorStream : ViewStream {
+      private ViewStream _source_stream;
+      private string _token;
+      private FileStream _out_fs;
+      private IBlueDataSerializer _serializer;
+      private string _file_name = String.Empty;
+      private long _rollover_size;
+      private readonly string _directory_path;
+      private int _n_updates_in_current_file = 0;
+
+      public PersistorStream(ViewStream src, string token, string directory, int rollover_size) {
+         _source_stream = src;
+         _token = token;
+         _directory_path = directory + $@"\{token}\";
+         _open_new_file();
+         _rollover_size = rollover_size;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _source_stream.onChange += _on_change;
+      }
+
+      protected override void myOnLastSubscriber() {
+         _source_stream.onChange -= _on_change;
+         _out_fs.Close();
+      }
+
+
+      public static DateTime parse_datetime_from_filename(string s) {
+         // allbooks_1697054438_2023-10-11_16-00-38
+         string[] toks = s.Split("_");
+         bts.Log.assert(toks.Length == 4);
+         string dt = $"{toks[2]}_{toks[3]}";
+         return parse_datetime(dt);
+      }
+
+      // this is used to parse the string passed the datetime texts passed to cons of the stream 
+      public static DateTime parse_datetime(string s) {
+         // for whatever reason "yyyy-MM-dd_HH-mm-ss" is not parsable using DateTime.ParseExact (it only gets
+         // the Date not the time), "yyyy-MM-dd_HH:mm:ss" is parsable
+         // however a file name can not have : in its name, therefore we need to parse "yyyy-MM-dd_HH-mm-ss"
+         DateTime rv = DateTime.ParseExact(s, PersistorStream.DateTime_format, CultureInfo.InvariantCulture);
+         string[] toks = s.Split("_");
+         string time_str = toks[1];
+         string[] time_toks = time_str.Split("-");
+         bts.Log.assert(time_toks.Length == 3);
+         int hh = Int32.Parse(time_toks[0]);
+         int mm = Int32.Parse(time_toks[1]);
+         int ss = Int32.Parse(time_toks[2]);
+         rv = rv.Date;
+         rv = rv.AddHours(hh);
+         rv = rv.AddMinutes(mm);
+         rv = rv.AddSeconds(ss);
+         return rv;
+      }
+
+      public static string DateTime_format {
+         get {
+            return "yyyy-MM-dd_HH-mm-ss";
+         }
+      }
+
+      public static long dt_to_epoch(DateTime dt) {
+         DateTimeOffset dtos = new DateTimeOffset(dt, TimeSpan.Zero);
+         return dtos.ToUnixTimeSeconds();
+      }
+      public static long epoch_now() {
+         return DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+      }
+
+      void _on_change(object new_value) {
+         DataPacket dp = new_value as DataPacket;
+         byte[] serialized_update = null;
+         bool _write_create = _serializer == null || _n_updates_in_current_file == 0;
+         _serializer = _serializer ?? new UniversalSerializer(dp.schema);
+         if (_write_create) {
+            // new files always starts with create
+            _serializer.serialize(StreamOpCode.create, new IBlueRowCollection[] { dp.newRows }, out serialized_update);
+         } else
+            _serializer.serialize(StreamOpCode.multipleRemoveAdd, new IBlueRowCollection[] { dp.deletedRows, dp.addedRows }, out serialized_update);
+
+         BinaryWriter bw = new BinaryWriter(_out_fs);
+         long utc_epoch = epoch_now();
+
+         //time, length of data, data
+         bw.Write(utc_epoch);
+         bw.Write(serialized_update.Length);
+         bw.Write(serialized_update);
+         _out_fs.Flush();
+         myFireEvent(dp);
+         _n_updates_in_current_file++;
+         if (_out_fs.Length > _rollover_size) {
+            _close_current_and_open_new();
+         }
+      }
+
+      void _close_current_and_open_new() {
+         _out_fs.Close();
+         _open_new_file();
+      }
+
+      void _open_new_file() {
+         var epoch = epoch_now();
+         _n_updates_in_current_file = 0;
+         // Check if the directory was successfully created
+         if (!Directory.Exists(_directory_path)) {
+            Directory.CreateDirectory(_directory_path);
+         }
+         _file_name = $"{_directory_path}{_token}_{epoch}_{DateTime.Now.ToString(DateTime_format)}";
+         _out_fs = new FileStream(_file_name, FileMode.OpenOrCreate);
+      }
+   }
+}

src/DataStreamSuite/DataStream/Primitives/FileStreams/PlaybackStream.cs

@@ -1,117 +1,190 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.IO;
-using System.Runtime.Serialization.Formatters.Binary;
-using BCG.Utilities.General;
-using BCG.Utilities;
-
-namespace BCG
-{
-   public delegate void PlaybackStreamProgress(long readFar, long totalBytesRead);
-   public class PlaybackStream : ViewStream, IWorker
-   {
-
-      public PlaybackStream(string fileName) : this(fileName, 1.0) { }
-
-      private string myFileName;
-      private FileStream myFileReader;
-      private double myPlaybackSpeed;
-      private DateTime myPlaybackStart;
-      private DateTime myNextPacketTime;
-      private IClientDeserializer myDeserializer;
-      private ITableAccumulator myAccumulator;
-
-      private BlueTable myLastTableVersion;
-
-      public PlaybackStream(string fileName, double playbackSpeed)
-      {
-         myFileName = fileName;
-         myPlaybackSpeed = playbackSpeed;
-      }
-
-      protected override void myOnFirstSubscriber()
-      {         myPlaybackStart = DateTime.Now;
-         myNextPacketTime = DateTime.MinValue;
-         myFileReader = new FileStream(myFileName, FileMode.Open, FileAccess.Read, FileShare.Read);
-         myReadNextPacketTime();
-         ViewStreamDatabase.instance.addWorker(this);
-      }
-
-      protected override void myOnLastSubscriber()
-      {
-         if (myFileReader != null)
-            myFileReader.Close();
-         ViewStreamDatabase.instance.removeWorker(this);
-      }
-
-      protected void myReadNextPacketTime()
-      {
-         if (myFileReader.Position == myFileReader.Length)
-         {
-            myNextPacketTime = DateTime.MaxValue;
-            myFileReader.Dispose();
-            if (onFileExhausted != null)
-               onFileExhausted();
-         }
-         else
-         {
-            double secondsElapsed = new BinaryReader(myFileReader).ReadDouble();
-            myNextPacketTime = myPlaybackStart + new TimeSpan(0, 0, 0, 0, (int)(1000 * secondsElapsed / myPlaybackSpeed));
-            if (onProgress != null)
-               onProgress(myFileReader.Position, myFileReader.Length);
-         }
-      }
-
-      public event PlaybackStreamProgress onProgress;
-      public event Action onFileExhausted;
+// using System;
+// using System.Collections.Generic;
+// using System.Linq;
+// using System.Text;
+// using System.IO;
+// using System.Runtime.Serialization.Formatters.Binary;
+// using BCG.Utilities.General;
+// using bts.collections;
+// using System.Reflection.Metadata;
 
 
-      #region IWorker Members
+// namespace BCG {
 
-      public void doWork()
-      {
-         if (myNextPacketTime <= DateTime.Now)
-         {
-            if (myDeserializer == null)
-            {
-               myDeserializer = new ClientUniversalDeserializer();
-               myAccumulator = new TableAccumulator(myFileName, null);
-            }
+//    public class PlaybackStream : ViewStream, IWorker {
+//       private readonly PlaybackType _type;
+//       private BlueTable _current_table;
+//       private IClientDeserializer _deserilializer = new ClientUniversalDeserializer();
+//       // these are the packets already downloaded from the current file
+//       private List<PlaybackPacket> _packets = new List<PlaybackPacket>();
+//       //private IEnumerable<FileStream> _file_streams = new List<FileStream>();
+//       private IEnumerable<string> _file_names;
+//       private Tuple<int, FileStream> _current_fs = new Tuple<int, FileStream>(-1, null);
+//       private DateTime _playback_t0, _playback_t1;
+//       private bool _all_files_read = false;
+//       SnapshotData _snapshot_data = null; // only initialized when in snapshot mode
 
-            BinaryReader reader = new BinaryReader(myFileReader);
-            int numBytes = reader.ReadInt32();
-            byte[] thisData = reader.ReadBytes(numBytes);
-            byte[] ops;
-            Array resultRowCollections;
-            myDeserializer.deserialize(new Stream[] { new MemoryStream(thisData) }, out ops, out resultRowCollections);
+//       public PlaybackStream(string datetime_start, string datetime_end, string directory_name, string token) {
+//          _type = PlaybackType.Streaming;
+//          _playback_t0 = PersistorStream.parse_datetime(datetime_start);
+//          _playback_t1 = PersistorStream.parse_datetime(datetime_end);
+//          string token_directory_name = $"{directory_name}\\{token}";
+//          bts.Log.Gen.info($"PlaybackStream t0: {_playback_t0} t1: {_playback_t1} dir: {token_directory_name}");
+//          List<string> files_in_range = new List<string>();
+//          if (Directory.Exists(token_directory_name)) {
+//             _file_names =
+//          Directory.GetFiles(token_directory_name).Where(f => {
+//             DateTime file_time = PersistorStream.parse_datetime_from_filename(f);
+//             return file_time > _playback_t0 && file_time < _playback_t1;
+//          });
+//          }
+//       }
 
-            //there should only be one op in there becuae we just read a single update.
-            // BlueEventLog.logAssert(ops.Length == 1,"Playback stream got " +ops.Length.ToString() + " op codes in one update, from stream file "+myFileName);
-            //there shoudl only be one set of collections becaue there was just a single op code 
-            //(those two arrays are parallel)
-            // BlueEventLog.logAssert(resultRowCollections.Length == 1, "StreamOpCode was create, serializer should return exactly 1 set of rows");
+//       protected override void myOnFirstSubscriber() {
+//          FileStream fs = new FileStream(_snapshot_data.snapshot_file, FileMode.Open, FileAccess.Read);
+//          _snapshot_data.packets = StreamPersistorUtils.load_packets_from_file(fs);
+//          PlaybackPacket snapshot_packet = StreamPersistorUtils.find_packet_at_time(_snapshot_data.packets, _snapshot_data.snapshot_time);
+//          if (snapshot_packet != null) {
+//             foreach (PlaybackPacket p in _snapshot_data.packets) {
+//                byte[] ops;
+//                Array row_array;
+//                _deserilializer.deserialize(new Stream[] { new MemoryStream(p.data) }, out ops, out row_array);
+//                for (int i = 0; i < ops.Length; i++) {
+//                   IBlueRowCollection[] rows_args = row_array.GetValue(i) as IBlueRowCollection[];
+//                   byte op = ops[i];
+//                   if (op == StreamOpCode.create) {
+//                      IBlueRowCollection full_table = rows_args[0];
+//                      _current_table = new BlueTable(full_table);
+//                   } else if (op == StreamOpCode.multipleRemoveAdd) {
+//                      //IBlueRowCollection[] del_added = rows_args.GetValue(0) as IBlueRowCollection[];
+//                      IBlueRowCollection dels = rows_args.GetValue(0) as IBlueRowCollection;
+//                      IBlueRowCollection adds = rows_args.GetValue(1) as IBlueRowCollection;
+//                      BlueDataUtility.absorbChanges(_current_table, dels, adds);
+//                   } else {
+//                      bts.Log.assert(false, $"Oprator: {op} is not expected");
+//                   }
+//                   if (p.idx == snapshot_packet.idx) {
+//                      myFireEvent(new DataPacket(_current_table, _current_table, new BlueTable(_current_table.schema)));
+//                      break;
+//                   }
+//                }
+//             }
+//          }
+//       }
 
-            if (ops[0] == (byte)StreamOpCode.create)
-            {
-               myLastTableVersion = new BlueTable((resultRowCollections.GetValue(0) as IBlueRowCollection[])[0]);
-               myFireEvent(new DataPacket(myLastTableVersion, new BlueTable(myLastTableVersion.schema), new BlueTable(myLastTableVersion.schema)));
-            }
-            else
-            {
-               // BlueEventLog.logAssert(ops[0] == (byte)StreamOpCode.multipleRemoveAdd, "Playback stream got unexpected open code " + ops[0].ToString() + " from file " + myFileName);
-               // BlueEventLog.logAssert(myLastTableVersion != null, "Playback stream for file "+myFileName + "got a non-create before a create");
-               IBlueRowCollection[] deletedAndAdded = resultRowCollections.GetValue(0) as IBlueRowCollection[];
-               BlueDataUtility.absorbChanges(myLastTableVersion, deletedAndAdded[0], deletedAndAdded[1]);
-               myFireEvent(new DataPacket(myLastTableVersion, deletedAndAdded[1], deletedAndAdded[0]));
-            }
-            
-            myReadNextPacketTime();
-         }
 
-      }
+//       private void _load_packets_from_current_file() {
+//          int curr_idx = _current_fs.Item1;
+//          FileStream curr_fs = _current_fs.Item2;
+//          _packets = new List<PlaybackPacket>();
+//          _packets.AddRange(StreamPersistorUtils.load_packets_from_file(curr_fs));
+//       }
 
-      #endregion
-   }
-}
+//       private bool current_file_all_replayed {
+//          get {
+//             bool rv = true;
+//             _packets.ForEach(p => rv = rv && p.replayed);
+//             return rv;
+//          }
+//       }
+
+//       protected override void myOnLastSubscriber() {
+//          var fs = _current_fs.Item2;
+//          if (fs != null) {
+//             fs.Close();
+//          }
+//          ViewStreamDatabase.instance.removeWorker(this);
+//       }
+
+//       // public event PlaybackStreamProgress onProgress;
+//       // public event Action onFileExhausted;
+//       private PlaybackPacket _locate_packet_to_replay() {
+//          foreach (var p in _packets) {
+//             // returns the first non replayed packet
+//             if (!p.replayed)
+//                return p;
+//          }
+//          //else
+//          {
+//             double secondsElapsed = new BinaryReader(myFileReader).ReadDouble();
+//             myNextPacketTime = myPlaybackStart + new TimeSpan(0, 0, 0, 0, (int)(1000 * secondsElapsed / myPlaybackSpeed));
+//             if (onProgress != null)
+//                onProgress(myFileReader.Position, myFileReader.Length);
+//          }
+//       }
+
+//       #region IWorker Members
+
+//       public void doWork() {
+//          if (_all_files_read)
+//             return;
+//          if (current_file_all_replayed) {
+//             _load_next_file();
+//          }
+//          PlaybackPacket curr_packet = _locate_packet_to_replay();
+//          if (curr_packet.idx == 0) { // first packet in the file, fire it rightaway 
+//             byte[] ops;
+//             Array row_array;
+//             // what a stupid interface!
+//             _deserilializer.deserialize(new Stream[] { new MemoryStream(curr_packet.data) }, out ops, out row_array);
+//             _fire_packet(ops, row_array);
+//             curr_packet.replay_timestamp = PersistorStream.epoch_now();
+//          } else {
+//             PlaybackPacket prev_packet = _get_previous_packet(curr_packet);
+//             // this is the time we need to fire (replay) this packet
+//             long time_to_fire = prev_packet.replay_timestamp + curr_packet.offset_from_previous;
+//             long now_epoch = PersistorStream.epoch_now();
+//             // fire when we are past the 
+//             if (now_epoch >= time_to_fire) {
+//                byte[] ops;
+//                Array row_array;
+//                _deserilializer.deserialize(new Stream[] { new MemoryStream(curr_packet.data) }, out ops, out row_array);
+//                _fire_packet(ops, row_array);
+//                curr_packet.replay_timestamp = PersistorStream.epoch_now();
+//             }
+//          }
+//       }
+
+//       private void _fire_packet(byte[] ops, Array row_array) {
+//          for (int i = 0; i < ops.Length; i++) {
+//             IBlueRowCollection[] rows_args = row_array.GetValue(i) as IBlueRowCollection[];
+//             byte op = ops[i];
+//             if (op == StreamOpCode.create) {
+//                IBlueRowCollection full_table = rows_args[0];
+//                _current_table = new BlueTable(full_table);
+//                //_current_table.addRows(full_table);
+//                myFireEvent(new DataPacket(full_table, full_table, myLastValue == null ? new BlueTable(full_table.schema) :
+//                                           (myLastValue as DataPacket).newRows));
+//             } else if (op == StreamOpCode.multipleRemoveAdd) {
+//                //IBlueRowCollection[] del_added = rows_args.GetValue(0) as IBlueRowCollection[];
+//                IBlueRowCollection dels = rows_args.GetValue(0) as IBlueRowCollection;
+//                IBlueRowCollection adds = rows_args.GetValue(1) as IBlueRowCollection;
+//                BlueDataUtility.absorbChanges(_current_table, dels, adds);
+//                myFireEvent(new DataPacket(_current_table, adds, dels));
+//             } else {
+//                bts.Log.assert(false, $"Oprator: {op} is not expected");
+//             }
+
+//          }
+//       }
+
+//       private void _load_next_file() {
+//          var new_idx = _current_fs.Item1 + 1;
+//          if (new_idx >= _file_names.Count()) {
+//             _all_files_read = true;
+//             bts.Log.Gen.info("All files read");
+//             return;
+//          }
+//          var prev_fs = _current_fs.Item2;
+//          if (prev_fs != null)
+//             prev_fs.Close();
+//          var new_filename = _file_names.ElementAt(new_idx);
+//          bts.Log.Gen.info("PlaybackStream_load_next_file new_filename=: {new_filename}");
+//          var new_fs = new FileStream(new_filename, FileMode.Open, FileAccess.Read);
+//          _current_fs = new Tuple<int, FileStream>(new_idx, new_fs);
+//          _load_packets_from_current_file();
+//       }
+
+//       #endregion
+//    }
+// }

src/DataStreamSuite/DataStream/Primitives/FileStreams/SnapshotStream.cs

@@ -0,0 +1,129 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.IO;
+using System.Runtime.Serialization.Formatters.Binary;
+using BCG.Utilities.General;
+using bts.collections;
+using System.Reflection.Metadata;
+
+
+namespace BCG {
+   public class SnapshotStream : ViewStream {
+      public enum SpecificSnapshot {
+         FirstOfDay,
+         LastOfDay
+      };
+      private BlueTable _current_table;
+      private IClientDeserializer _deserilializer = new ClientUniversalDeserializer();
+      public DateTime _snapshot_time;
+      public string _snapshot_file;
+      public IEnumerable<PlaybackPacket> _packets;
+      public SnapshotStream(string snapshot_date, string specific_snapshot, string directory_name, string token) {
+         DateTime dt;
+         var parsed = DateTime.TryParse(snapshot_date, out dt);
+         dt = dt.Date;
+         bts.Log.assert(parsed);
+         SpecificSnapshot specific_snapshot_enum;
+         parsed = Enum.TryParse<SpecificSnapshot>(specific_snapshot, out specific_snapshot_enum);
+         bts.Log.assert(parsed);
+         string snapshot_dt = StreamPersistorUtils.find_snapshot_file($"{directory_name}\\{token}", dt, specific_snapshot_enum);
+         ViewStream rs = new SnapshotStream(snapshot_dt, directory_name, token);
+         mySetRealSource(rs);
+      }
+
+      public SnapshotStream(string snapshot_dt, string directory_name, string token) {
+         _snapshot_time = PersistorStream.parse_datetime(snapshot_dt);
+         string token_directory_name = $"{directory_name}\\{token}";
+         _snapshot_file = StreamPersistorUtils.find_snapshot_file(token_directory_name, _snapshot_time);
+      }
+
+      protected override void myOnFirstSubscriber() {
+         FileStream fs = new FileStream(_snapshot_file, FileMode.Open, FileAccess.Read);
+         _packets = StreamPersistorUtils.load_packets_from_file(fs);
+         PlaybackPacket snapshot_packet = StreamPersistorUtils.find_packet_at_time(_packets, _snapshot_time);
+         if (snapshot_packet != null) {
+            foreach (PlaybackPacket p in _packets) {
+               byte[] ops;
+               Array row_array;
+               _deserilializer.deserialize(new Stream[] { new MemoryStream(p.data) }, out ops, out row_array);
+               for (int i = 0; i < ops.Length; i++) {
+                  IBlueRowCollection[] rows_args = row_array.GetValue(i) as IBlueRowCollection[];
+                  byte op = ops[i];
+                  if (op == StreamOpCode.create) {
+                     IBlueRowCollection full_table = rows_args[0];
+                     _current_table = new BlueTable(full_table);
+                  } else if (op == StreamOpCode.multipleRemoveAdd) {
+                     //IBlueRowCollection[] del_added = rows_args.GetValue(0) as IBlueRowCollection[];
+                     IBlueRowCollection dels = rows_args.GetValue(0) as IBlueRowCollection;
+                     IBlueRowCollection adds = rows_args.GetValue(1) as IBlueRowCollection;
+                     BlueDataUtility.absorbChanges(_current_table, dels, adds);
+                  } else {
+                     bts.Log.assert(false, $"Oprator: {op} is not expected");
+                  }
+                  if (p.idx == snapshot_packet.idx) {
+                     myFireEvent(new DataPacket(_current_table, _current_table, new BlueTable(_current_table.schema)));
+                     break;
+                  }
+               }
+            }
+         }
+      }
+
+      private void _absorb_packet(byte[] ops, Array row_array) {
+         for (int i = 0; i < ops.Length; i++) {
+            IBlueRowCollection[] rows_args = row_array.GetValue(i) as IBlueRowCollection[];
+            byte op = ops[i];
+            if (op == StreamOpCode.create) {
+               IBlueRowCollection full_table = rows_args[0];
+               _current_table = new BlueTable(full_table);
+            } else if (op == StreamOpCode.multipleRemoveAdd) {
+               //IBlueRowCollection[] del_added = rows_args.GetValue(0) as IBlueRowCollection[];
+               IBlueRowCollection dels = rows_args.GetValue(0) as IBlueRowCollection;
+               IBlueRowCollection adds = rows_args.GetValue(1) as IBlueRowCollection;
+               BlueDataUtility.absorbChanges(_current_table, dels, adds);
+            } else {
+               bts.Log.assert(false, $"Operator: {op} is not expected");
+            }
+         }
+      }
+
+      protected override void myOnLastSubscriber() {
+      }
+
+      // public event SnapshotStream.Progress onProgress;
+      // public event Action onFileExhausted;
+      private PlaybackPacket _locate_packet_to_replay() {
+         foreach (var p in _packets) {
+            // returns the first non replayed packet
+            if (!p.replayed)
+               return p;
+         }
+         return null;
+      }
+
+      private void _fire_packet(byte[] ops, Array row_array) {
+         for (int i = 0; i < ops.Length; i++) {
+            IBlueRowCollection[] rows_args = row_array.GetValue(i) as IBlueRowCollection[];
+            byte op = ops[i];
+            if (op == StreamOpCode.create) {
+               IBlueRowCollection full_table = rows_args[0];
+               _current_table = new BlueTable(full_table);
+               //_current_table.addRows(full_table);
+               myFireEvent(new DataPacket(full_table, full_table, myLastValue == null ? new BlueTable(full_table.schema) :
+                                          (myLastValue as DataPacket).newRows));
+            } else if (op == StreamOpCode.multipleRemoveAdd) {
+               //IBlueRowCollection[] del_added = rows_args.GetValue(0) as IBlueRowCollection[];
+               IBlueRowCollection dels = rows_args.GetValue(0) as IBlueRowCollection;
+               IBlueRowCollection adds = rows_args.GetValue(1) as IBlueRowCollection;
+               BlueDataUtility.absorbChanges(_current_table, dels, adds);
+               myFireEvent(new DataPacket(_current_table, adds, dels));
+            } else {
+               bts.Log.assert(false, $"Oprator: {op} is not expected");
+            }
+
+         }
+      }
+   }
+}

src/DataStreamSuite/DataStream/Primitives/FileStreams/StreamPersistorUtils.cs

@@ -0,0 +1,159 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Globalization;
+using System.IO;
+
+
+namespace BCG {
+   // each stream op in the replay file is reprsented by a packet here
+   public class PlaybackPacket {
+      public readonly int idx;
+      public readonly long timestamp;
+      public readonly byte[] data;
+      public long replay_timestamp = 0; // non zero it has been replayed
+      public long offset_from_previous = 0;
+      public PlaybackPacket(int the_idx, long the_timestamp, byte[] the_data) {
+         this.idx = the_idx;
+         this.timestamp = the_timestamp;
+         this.data = the_data;
+      }
+      public bool replayed {
+         get { return replay_timestamp != 0; }
+      }
+   }
+
+   public enum PlaybackType {
+      Streaming = 0,
+      Snapshot
+   }
+   public class SnapshotData {
+      public DateTime snapshot_time;
+      public string snapshot_file;
+      public SnapshotData(DateTime snapshot_time_arg, string snapshot_file_arg) {
+         snapshot_time = snapshot_time_arg;
+         snapshot_file = snapshot_file_arg;
+      }
+      public IEnumerable<PlaybackPacket> packets = new List<PlaybackPacket>();
+   }
+   public static class StreamPersistorUtils {
+      public static string find_snapshot_file(string directory_name, DateTime snapshot_date, SnapshotStream.SpecificSnapshot specific_snapshot) {
+         DateTime max_dt = DateTime.MinValue;
+         string rv = String.Empty;
+         string[] file_names = Directory.GetFiles(directory_name);
+         for (int i = 0; i < file_names.Count() - 1; i++) {
+            string fn = file_names[i];
+            var dt = parse_datetime_from_filename(fn);
+            if (dt > max_dt) {
+               max_dt = dt;
+               rv = fn;
+            }
+         }
+         return rv;
+      }
+      public static string find_snapshot_file(string directory_name, DateTime snapshot_time) {
+         string[] file_names = Directory.GetFiles(directory_name);
+         for (int i = 0; i < file_names.Count() - 1; i++) {
+            string fn = file_names[i];
+            string next_fn = file_names[i + 1];
+            DateTime f_dt = PersistorStream.parse_datetime_from_filename(fn);
+            DateTime next_f_dt = PersistorStream.parse_datetime_from_filename(next_fn);
+            if (snapshot_time >= f_dt && snapshot_time <= next_f_dt) {
+               return fn;
+            }
+         }
+         return String.Empty;
+      }
+      public static DateTime parse_datetime_from_filename(string s) {
+         // allbooks_1697054438_2023-10-11_16-00-38
+         string[] toks = s.Split("_");
+         bts.Log.assert(toks.Length == 4);
+         string dt = $"{toks[2]}_{toks[3]}";
+         return parse_datetime(dt);
+      }
+
+      // this is used to parse the string passed the datetime texts passed to cons of the stream 
+      public static DateTime parse_datetime(string s) {
+         // for whatever reason "yyyy-MM-dd_HH-mm-ss" is not parsable using DateTime.ParseExact (it only gets
+         // the Date not the time), "yyyy-MM-dd_HH:mm:ss" is parsable
+         // however a file name can not have : in its name, therefore we need to parse "yyyy-MM-dd_HH-mm-ss"
+         DateTime rv = DateTime.ParseExact(s, PersistorStream.DateTime_format, CultureInfo.InvariantCulture);
+         string[] toks = s.Split("_");
+         string time_str = toks[1];
+         string[] time_toks = time_str.Split("-");
+         bts.Log.assert(time_toks.Length == 3);
+         int hh = Int32.Parse(time_toks[0]);
+         int mm = Int32.Parse(time_toks[1]);
+         int ss = Int32.Parse(time_toks[2]);
+         rv = rv.Date;
+         rv = rv.AddHours(hh);
+         rv = rv.AddMinutes(mm);
+         rv = rv.AddSeconds(ss);
+         return rv;
+      }
+
+      public static string DateTime_format {
+         get {
+            return "yyyy-MM-dd_HH-mm-ss";
+         }
+      }
+
+      public static long dt_to_epoch(DateTime dt) {
+         DateTimeOffset dtos = new DateTimeOffset(dt, TimeSpan.Zero);
+         return dtos.ToUnixTimeSeconds();
+      }
+      public static long epoch_now() {
+         return DateTimeOffset.UtcNow.ToUnixTimeSeconds();
+      }
+      public static DateTime epoch_to_dt(long epoch_seconds) {
+         return DateTimeOffset.FromUnixTimeSeconds(epoch_seconds).DateTime;
+      }
+
+      public static PlaybackPacket find_packet_at_time(IEnumerable<PlaybackPacket> packets, DateTime snapshot_time) {
+         log_file_ts(packets, snapshot_time);
+         long snapshot_time_epoch = PersistorStream.dt_to_epoch(snapshot_time);
+         for (int i = 0; i < packets.Count() - 1; i++) {
+            PlaybackPacket curr_p = packets.ElementAt(i);
+            PlaybackPacket next_p = packets.ElementAt(i + 1);
+            if (curr_p.timestamp <= snapshot_time_epoch && next_p.timestamp >= snapshot_time_epoch) {
+               return curr_p;
+            }
+         }
+         // if for some reason it cant find it, send the last packet
+         return packets.Last();
+      }
+
+      private static void log_file_ts(IEnumerable<PlaybackPacket> packets, DateTime snapshot_time) {
+         string big_log_msg = String.Empty;
+         foreach (var p in packets) {
+            big_log_msg += $"packet idx: {p.idx} epoch_ts: {p.timestamp} ts: {epoch_to_dt(p.timestamp)} snapshot_time: {snapshot_time}";
+            big_log_msg += "\n";
+         }
+         bts.Log.Gen.info($"Packets: {big_log_msg}");
+      }
+
+      public static IEnumerable<PlaybackPacket> load_packets_from_file(FileStream fs) {
+         BinaryReader br = new BinaryReader(fs);
+         List<PlaybackPacket> rv = new List<PlaybackPacket>();
+         while (fs.Position < fs.Length) {
+            try {
+               long ts = br.ReadInt64();
+               int sz = br.ReadInt32();
+               byte[] data = br.ReadBytes(sz);
+               var pb = new PlaybackPacket(rv.Count, ts, data);
+               rv.Add(pb);
+            } catch (Exception ex) {
+               bts.Log.Gen.error($"ex: {ex}");
+               break;
+            }
+         }
+         // setting offset field
+         for (int i = 0; i < rv.Count; i++) {
+            if (i == 0)
+               continue;
+            rv[i].offset_from_previous = rv[i].timestamp - rv[i - 1].timestamp;
+         }
+         return rv;
+      }
+   }
+}

src/DataStreamSuite/DataStream/Primitives/GroupBy/MaxGroupByEvaluator.cs

@@ -1,47 +1,42 @@
-// using System;
-// using System.Collections;
-// using BCG.Utilities;
+using System;
+using System.Collections;
 
-// namespace BCG
-// {
-// 	/// <summary>
-// 	/// Computes the max for a given column
-// 	/// </summary>
-// 	public class MaxGroupByEvaluator : GroupByEvaluator
-// 	{
+using BCG.Utilities;
 
-//       public MaxGroupByEvaluator (string outputCol, string[] groupByCols) : base (outputCol, groupByCols)
-//       {}
+namespace BCG {
+    /// <summary>
+    /// Computes the max for a given column
+    /// </summary>
+    public class MaxGroupByEvaluator : GroupByEvaluator {
 
-//       public MaxGroupByEvaluator (string colMapEpression, string outputCol, string[] groupByCols)
-//          : base (colMapEpression, outputCol, groupByCols)   {}
+        public MaxGroupByEvaluator(string outputCol, string[] groupByCols) : base(outputCol, groupByCols) { }
 
-//       public override IBlueRow evaluate (DataPacket dp)  
-//       {
-//          myOutputTable = myOutputTable == null ? new GroupByOutputTable (dp.schema) :
-//             myOutputTable;
-//          string hashString = BlueDataUtility.rowToString (GroupByStream.getRepRow (dp), myGroupByCols);
-//          IBlueRow currMaxRow = myOutputTable.getRow (hashString);
-//          IBlueRow maxRow = BlueDataUtility.computeMaxRow (dp.deletedRows, myOutputColumn);
-//          if (maxRow != null)
-//          {
-//             BlueEventLog.logAssert (currMaxRow != null);
-//             BlueEventLog.logAssert (BlueDataUtility.compareRows (maxRow, currMaxRow, myOutputColumn) <= 0);
-//             if (BlueDataUtility.compareRows (maxRow, currMaxRow, myOutputColumn) == 0)
-//             {
-//                maxRow = BlueDataUtility.computeMaxRow (dp.newRows, myOutputColumn);
-//                if (maxRow == null)
-//                   myOutputTable.removeRow (hashString);
-//                else
-//                   myOutputTable.addRow (maxRow, hashString);
-//             }
-//          }
-//          maxRow = BlueDataUtility.computeMaxRow (dp.addedRows, myOutputColumn);
-//          // if the row was replaced in the above lines, then currMaxRow < maxRow, so the if below would never return a true,
-//          // otherwise if maxRow > currMaxRow then its replaced
-//          if (maxRow != null && (currMaxRow == null || BlueDataUtility.compareRows (maxRow, currMaxRow, myOutputColumn) > 0))
-//             myOutputTable.addRow (maxRow, hashString);
-//          return myProject (myOutputTable.getRow (hashString));
-//       }
-// 	}
-// }
+        public MaxGroupByEvaluator(string colMapEpression, string outputCol, string[] groupByCols)
+           : base(colMapEpression, outputCol, groupByCols) { }
+
+        public override IBlueRow evaluate(DataPacket dp) {
+            myOutputTable = myOutputTable == null ? new GroupByOutputTable(dp.schema) :
+               myOutputTable;
+            string hashString = BlueDataUtility.rowToString(GroupByStream.getRepRow(dp), myGroupByCols);
+            IBlueRow currMaxRow = myOutputTable.getRow(hashString);
+            IBlueRow maxRow = BlueDataUtility.computeMaxRow(dp.deletedRows, myOutputColumn);
+            if (maxRow != null) {
+                bts.Log.assert(currMaxRow != null);
+                bts.Log.assert(BlueDataUtility.compareRows(maxRow, currMaxRow, myOutputColumn) <= 0);
+                if (BlueDataUtility.compareRows(maxRow, currMaxRow, myOutputColumn) == 0) {
+                    maxRow = BlueDataUtility.computeMaxRow(dp.newRows, myOutputColumn);
+                    if (maxRow == null)
+                        myOutputTable.removeRow(hashString);
+                    else
+                        myOutputTable.addRow(maxRow, hashString);
+                }
+            }
+            maxRow = BlueDataUtility.computeMaxRow(dp.addedRows, myOutputColumn);
+            // if the row was replaced in the above lines, then currMaxRow < maxRow, so the if below would never return a true,
+            // otherwise if maxRow > currMaxRow then its replaced
+            if (maxRow != null && (currMaxRow == null || BlueDataUtility.compareRows(maxRow, currMaxRow, myOutputColumn) > 0))
+                myOutputTable.addRow(maxRow, hashString);
+            return myProject(myOutputTable.getRow(hashString));
+        }
+    }
+}

src/DataStreamSuite/DataStream/Primitives/GroupBy/MaxStream.cs

@@ -1,20 +1,15 @@
-// using System;
+using System;
 
-// namespace BCG
-// {
-// 	public class MaxStream : ViewStream
-// 	{
-//       public MaxStream(ViewStream stream, string outputCol, string inputCols) : this(stream, outputCol, inputCols.Split(' '))
-//       {
-//       }
-// 		public MaxStream (ViewStream stream, string outputCol, string[] inputCols)
-// 		{
-//          mySetRealSource (new GroupByStream (stream, 
-//                                              new MaxGroupByEvaluator (outputCol, inputCols)));
-// 		}
+namespace BCG {
+    public class MaxStream : ViewStream {
+        public MaxStream(ViewStream stream, string outputCol, string inputCols) : this(stream, outputCol, inputCols.Split(' ')) {
+        }
+        public MaxStream(ViewStream stream, string outputCol, string[] inputCols) {
+            mySetRealSource(new GroupByStream(stream,
+                                                new MaxGroupByEvaluator(outputCol, inputCols)));
+        }
 
-//       public MaxStream (ViewStream stream, string outputCol)
-//          : this (new AddColumnsStream (stream, "fakeCol=0"), outputCol, new string[]{"fakeCol"})
-//       {}
-// 	}
-// }
+        public MaxStream(ViewStream stream, string outputCol)
+           : this(new AddColumnsStream(stream, "fakeCol=0"), outputCol, new string[] { "fakeCol" }) { }
+    }
+}

src/DataStreamSuite/DataStream/Primitives/GroupBy/MinGroupByEvaluator.cs

@@ -1,40 +1,36 @@
-// using System;
-// using BCG.Utilities;
+using System;
 
-// namespace BCG
-// {
-//    public class MinGroupByEvaluator : MaxGroupByEvaluator
-//    {
-//       public MinGroupByEvaluator (string outputCol, string[] groupByCols) 
-//          : base (outputCol, groupByCols)  {}
+using BCG.Utilities;
 
-//       public MinGroupByEvaluator (string colMapEpression, string outputCol, string[] groupByCols) :
-//          base (colMapEpression, outputCol, groupByCols)  {}
+namespace BCG {
+    public class MinGroupByEvaluator : MaxGroupByEvaluator {
+        public MinGroupByEvaluator(string outputCol, string[] groupByCols)
+           : base(outputCol, groupByCols) { }
 
-//       public override IBlueRow evaluate (DataPacket dp)  
-//       {
-//          myOutputTable = myOutputTable == null ? new GroupByOutputTable (dp.schema) : myOutputTable;
-//          string stringRep = BlueDataUtility.rowToString (GroupByStream.getRepRow (dp), myGroupByCols);
-//          IBlueRow currMinRow = myOutputTable.getRow (stringRep);
-//          IBlueRow minRow = BlueDataUtility.computeMinRow (dp.deletedRows, myOutputColumn);
-//          if (minRow != null)
-//          {
-//             // BlueEventLog.logAssert (currMinRow != null);
-//             // BlueEventLog.logAssert (BlueDataUtility.compareRows (minRow, currMinRow, myOutputColumn) >= 0);
-//             if (BlueDataUtility.compareRows (minRow, currMinRow, myOutputColumn) == 0)
-//             {
-//                minRow = BlueDataUtility.computeMinRow (dp.newRows, myOutputColumn);
-//                if (minRow == null)
-//                   myOutputTable.removeRow (stringRep);
-//                else
-//                   myOutputTable.addRow (minRow, stringRep);
-//             }
-//          }
-//          minRow = BlueDataUtility.computeMinRow (dp.addedRows, myOutputColumn);
-//          if (minRow != null && (currMinRow == null || BlueDataUtility.compareRows (minRow, currMinRow, myOutputColumn) < 0))
-//             myOutputTable.addRow (minRow, stringRep);
-//          return myOutputTable.getRow (stringRep);
-//       }
+        public MinGroupByEvaluator(string colMapEpression, string outputCol, string[] groupByCols) :
+           base(colMapEpression, outputCol, groupByCols) { }
 
-//    }
-// }
+        public override IBlueRow evaluate(DataPacket dp) {
+            myOutputTable = myOutputTable == null ? new GroupByOutputTable(dp.schema) : myOutputTable;
+            string stringRep = BlueDataUtility.rowToString(GroupByStream.getRepRow(dp), myGroupByCols);
+            IBlueRow currMinRow = myOutputTable.getRow(stringRep);
+            IBlueRow minRow = BlueDataUtility.computeMinRow(dp.deletedRows, myOutputColumn);
+            if (minRow != null) {
+                // BlueEventLog.logAssert (currMinRow != null);
+                // BlueEventLog.logAssert (BlueDataUtility.compareRows (minRow, currMinRow, myOutputColumn) >= 0);
+                if (BlueDataUtility.compareRows(minRow, currMinRow, myOutputColumn) == 0) {
+                    minRow = BlueDataUtility.computeMinRow(dp.newRows, myOutputColumn);
+                    if (minRow == null)
+                        myOutputTable.removeRow(stringRep);
+                    else
+                        myOutputTable.addRow(minRow, stringRep);
+                }
+            }
+            minRow = BlueDataUtility.computeMinRow(dp.addedRows, myOutputColumn);
+            if (minRow != null && (currMinRow == null || BlueDataUtility.compareRows(minRow, currMinRow, myOutputColumn) < 0))
+                myOutputTable.addRow(minRow, stringRep);
+            return myOutputTable.getRow(stringRep);
+        }
+
+    }
+}

src/DataStreamSuite/DataStream/Primitives/GroupBy/MinStream.cs

@@ -1,17 +1,13 @@
-// using System;
+using System;
 
-// namespace BCG
-// {
-//    public class MinStream : ViewStream
-//    {
-//       public MinStream (ViewStream stream, string outputCol, string[] inputCol)
-//       {
-//          mySetRealSource (new GroupByStream (stream, 
-//                            new MinGroupByEvaluator (outputCol, inputCol)));
-//       }
+namespace BCG {
+    public class MinStream : ViewStream {
+        public MinStream(ViewStream stream, string outputCol, string[] inputCol) {
+            mySetRealSource(new GroupByStream(stream,
+                              new MinGroupByEvaluator(outputCol, inputCol)));
+        }
 
-//       public MinStream (ViewStream stream, string outputCol)
-//                      : this (new AddColumnsStream (stream, "fakeCol=0"), outputCol, new string[]{"fakeCol"})
-//       {}
-//    }
-// }
+        public MinStream(ViewStream stream, string outputCol)
+                       : this(new AddColumnsStream(stream, "fakeCol=0"), outputCol, new string[] { "fakeCol" }) { }
+    }
+}

src/DataStreamSuite/DataStream/Primitives/GroupBy/SumGroupByEvaluator.cs

@@ -1,94 +1,82 @@
-// using System;
+using System;
 
-// namespace BCG
-// {
-//    /// <summary>
-//    /// Computes the sum for a given column
-//    /// </summary>
-//    public class SumGroupByEvaluator : GroupByEvaluator
-//    {
-//       public SumGroupByEvaluator (string outputCol, string[] groupByCols) : base (outputCol, groupByCols)
-//       {}
+namespace BCG {
+    /// <summary>
+    /// Computes the sum for a given column
+    /// </summary>
+    public class SumGroupByEvaluator : GroupByEvaluator {
+        public SumGroupByEvaluator(string outputCol, string[] groupByCols) : base(outputCol, groupByCols) { }
 
-//       public SumGroupByEvaluator (string colMapEpression, string outputCol, string[] groupByCols)
-//          : base (colMapEpression, outputCol, groupByCols)   {}
+        public SumGroupByEvaluator(string colMapEpression, string outputCol, string[] groupByCols)
+           : base(colMapEpression, outputCol, groupByCols) { }
 
-//       public override IBlueRow evaluate (DataPacket dp)  
-//       {
-//          myOutputTable = myOutputTable == null ? new GroupByOutputTable (dp.schema) : myOutputTable;
-         
-//          IBlueRow sumRow = BlueDataUtility.computeSum(dp.newRows, myOutputColumn);
-//          return sumRow;
-//       }
-//    }
+        public override IBlueRow evaluate(DataPacket dp) {
+            myOutputTable = myOutputTable == null ? new GroupByOutputTable(dp.schema) : myOutputTable;
+
+            IBlueRow sumRow = BlueDataUtility.computeSum(dp.newRows, myOutputColumn);
+            return sumRow;
+        }
+    }
 
 
-//    public class MultiColumnSumGroupByEvaluator : IGroupByEvaluator
-//    {
-//       private string[] myOutputCols, myGroupByCols;
-//       public MultiColumnSumGroupByEvaluator(string spaceSeperatedOutputCols, string spaceSeperatedGroupByCols)
-//       {
-//          myOutputCols = spaceSeperatedOutputCols.Split(' ');
-//          myGroupByCols = spaceSeperatedGroupByCols.Split(' ');
-//       }
+    public class MultiColumnSumGroupByEvaluator : IGroupByEvaluator {
+        private string[] myOutputCols, myGroupByCols;
+        public MultiColumnSumGroupByEvaluator(string spaceSeperatedOutputCols, string spaceSeperatedGroupByCols) {
+            myOutputCols = spaceSeperatedOutputCols.Split(' ');
+            myGroupByCols = spaceSeperatedGroupByCols.Split(' ');
+        }
 
-//       public MultiColumnSumGroupByEvaluator(string[] output_columns, string[] groupby_columns)
-//       {
-//          myOutputCols = output_columns;
-//          myGroupByCols = groupby_columns;
-//       }
+        public MultiColumnSumGroupByEvaluator(string[] output_columns, string[] groupby_columns) {
+            myOutputCols = output_columns;
+            myGroupByCols = groupby_columns;
+        }
 
-//       #region IGroupByEvaluator Members
+        #region IGroupByEvaluator Members
 
-//       public IBlueRow evaluate(DataPacket packet)  {return BlueDataUtility.computeSum(packet.newRows, myOutputCols);}
+        public IBlueRow evaluate(DataPacket packet) { return BlueDataUtility.computeSum(packet.newRows, myOutputCols); }
 
-//       public string[] groupByColumns { get { return myGroupByCols; } }
+        public string[] groupByColumns { get { return myGroupByCols; } }
 
-//       public void clear()  {/*stateless*/}
+        public void clear() {/*stateless*/}
 
-//       public IBlueTableSchema getOutputSchema(IBlueTableSchema schema)  {return schema;}
+        public IBlueTableSchema getOutputSchema(IBlueTableSchema schema) { return schema; }
 
-//       #endregion
-//    }
+        #endregion
+    }
 
-//    public class SumGroupByEvaluator<T> : GroupByEvaluator
-//    {
-//       public SumGroupByEvaluator(string outputCol, string[] groupByCols)
-//          : base(outputCol, groupByCols)
-//       { }
+    public class SumGroupByEvaluator<T> : GroupByEvaluator {
+        public SumGroupByEvaluator(string outputCol, string[] groupByCols)
+           : base(outputCol, groupByCols) { }
 
-//       public SumGroupByEvaluator(string colMapEpression, string outputCol, string[] groupByCols)
-//          : base(colMapEpression, outputCol, groupByCols) { }
+        public SumGroupByEvaluator(string colMapEpression, string outputCol, string[] groupByCols)
+           : base(colMapEpression, outputCol, groupByCols) { }
 
-//       public override IBlueRow evaluate(DataPacket dp)
-//       {
-//          myOutputTable = myOutputTable == null ? new GroupByOutputTable(dp.schema) : myOutputTable;
+        public override IBlueRow evaluate(DataPacket dp) {
+            myOutputTable = myOutputTable == null ? new GroupByOutputTable(dp.schema) : myOutputTable;
 
-//          IBlueRow sumRow = BlueDataUtility.computeSum<T>(dp.newRows, myOutputColumn);
-//          return sumRow;
-//       }
-//    }
+            IBlueRow sumRow = BlueDataUtility.computeSum<T>(dp.newRows, myOutputColumn);
+            return sumRow;
+        }
+    }
 
-//    public class MultiColumnSumGroupByEvaluator<T> : IGroupByEvaluator
-//    {
-//       private string[] myOutputCols, myGroupByCols;
-//       public MultiColumnSumGroupByEvaluator(string spaceSeperatedOutputCols, string spaceSeperatedGroupByCols)
-//       {
-//          myOutputCols = spaceSeperatedOutputCols.Split(' ');
-//          myGroupByCols = spaceSeperatedGroupByCols.Split(' ');
-//       }
+    public class MultiColumnSumGroupByEvaluator<T> : IGroupByEvaluator {
+        private string[] myOutputCols, myGroupByCols;
+        public MultiColumnSumGroupByEvaluator(string spaceSeperatedOutputCols, string spaceSeperatedGroupByCols) {
+            myOutputCols = spaceSeperatedOutputCols.Split(' ');
+            myGroupByCols = spaceSeperatedGroupByCols.Split(' ');
+        }
 
-//       #region IGroupByEvaluator Members
+        #region IGroupByEvaluator Members
 
-//       public IBlueRow evaluate(DataPacket packet)  {return BlueDataUtility.computeSum<T>(packet.newRows, myOutputCols);}
+        public IBlueRow evaluate(DataPacket packet) { return BlueDataUtility.computeSum<T>(packet.newRows, myOutputCols); }
 
-//       public string[] groupByColumns { get { return myGroupByCols; } }
+        public string[] groupByColumns { get { return myGroupByCols; } }
 
-//       public void clear()  {/*stateless*/}
+        public void clear() {/*stateless*/}
 
-//       public IBlueTableSchema getOutputSchema(IBlueTableSchema schema)  {return schema;}
+        public IBlueTableSchema getOutputSchema(IBlueTableSchema schema) { return schema; }
 
-//       #endregion
-//    }
+        #endregion
+    }
 
-// }
+}

src/DataStreamSuite/DataStream/Primitives/GroupBy/SumStream.cs

@@ -1,107 +1,89 @@
-// using System;
-// using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 
-// namespace BCG
-// {
-//    public class NullMapper : IStreamMapper
-//    {
-//       private Dictionary<string, bool> _valid_cols = new Dictionary<string, bool>();
+namespace BCG {
+    public class NullMapper : IStreamMapper {
+        private Dictionary<string, bool> _valid_cols = new Dictionary<string, bool>();
 
-//       public NullMapper(string[] valid_cols)
-//       {
-//          foreach (string c in valid_cols)
-//             _valid_cols[c] = true;
-//          _valid_cols["id"] = true;
-//       }
+        public NullMapper(string[] valid_cols) {
+            foreach (string c in valid_cols)
+                _valid_cols[c] = true;
+            _valid_cols["id"] = true;
+        }
 
-//       public IBlueTableSchema getOutputSchema(IBlueTableSchema input_schema) { return input_schema; }
+        public IBlueTableSchema getOutputSchema(IBlueTableSchema input_schema) { return input_schema; }
 
-//       public IBlueRow map(IBlueRow row)
-//       {
-//          MutableBlueRow out_row = new MutableBlueRow(row);
-//          foreach (string c in row.schema.columnNames)
-//             if (!_valid_cols.ContainsKey(c))
-//                out_row.setValue(c, DBNull.Value);
-//          return out_row;
-//       }
-//    }
+        public IBlueRow map(IBlueRow row) {
+            MutableBlueRow out_row = new MutableBlueRow(row);
+            foreach (string c in row.schema.columnNames)
+                if (!_valid_cols.ContainsKey(c))
+                    out_row.setValue(c, DBNull.Value);
+            return out_row;
+        }
+    }
 
-//    public class SumStream : ViewStream
-//    {
-//       public SumStream(ViewStream stream, string spaceSeparatedOutputCols, string spaceSeparatedGroupByCols)
-//       {
-//          string[] outputCols = spaceSeparatedOutputCols.Split(' ');
-//          string[] groupByCols = spaceSeparatedGroupByCols.Split(' ');
-//          mySetRealSource(new GroupByStream(stream,
-//                                            outputCols.Length == 1 ? new SumGroupByEvaluator(outputCols[0], groupByCols) as IGroupByEvaluator :
-//                                            new MultiColumnSumGroupByEvaluator(spaceSeparatedOutputCols, spaceSeparatedGroupByCols)));
-//       }
+    public class SumStream : ViewStream {
+        public SumStream(ViewStream stream, string spaceSeparatedOutputCols, string spaceSeparatedGroupByCols) {
+            string[] outputCols = spaceSeparatedOutputCols.Split(' ');
+            string[] groupByCols = spaceSeparatedGroupByCols.Split(' ');
+            mySetRealSource(new GroupByStream(stream,
+                                              outputCols.Length == 1 ? new SumGroupByEvaluator(outputCols[0], groupByCols) as IGroupByEvaluator :
+                                              new MultiColumnSumGroupByEvaluator(spaceSeparatedOutputCols, spaceSeparatedGroupByCols)));
+        }
 
-//       public SumStream(ViewStream stream, string[] output_columns)
-//       {
-//          ViewStream rs = new AddColumnsStream(stream, "fake_col=0");
-//          rs = new SumStream(rs, output_columns, new string[] { "fake_col" }, false);
-//          rs = new ProjectStream(rs, "!fake_col");
-//          mySetRealSource(rs);
-//       }
+        public SumStream(ViewStream stream, string[] output_columns) {
+            ViewStream rs = new AddColumnsStream(stream, "fake_col=0");
+            rs = new SumStream(rs, output_columns, new string[] { "fake_col" }, false);
+            rs = new ProjectStream(rs, "!fake_col");
+            mySetRealSource(rs);
+        }
 
-//       public SumStream(ViewStream stream, string space_seperated_output_columns, string space_seperated_groupby_columns, bool force_null_into_other_columns)
-//       {
-//          string[] output_columns = space_seperated_output_columns.Split(' ');
-//          string[] groupby_columns = String.IsNullOrEmpty (space_seperated_groupby_columns) ? new string[]{} : space_seperated_groupby_columns.Split (' ');
-//          mySetRealSource (new SumStream (stream, output_columns, groupby_columns, force_null_into_other_columns));
-//       }
+        public SumStream(ViewStream stream, string space_seperated_output_columns, string space_seperated_groupby_columns, bool force_null_into_other_columns) {
+            string[] output_columns = space_seperated_output_columns.Split(' ');
+            string[] groupby_columns = String.IsNullOrEmpty(space_seperated_groupby_columns) ? new string[] { } : space_seperated_groupby_columns.Split(' ');
+            mySetRealSource(new SumStream(stream, output_columns, groupby_columns, force_null_into_other_columns));
+        }
 
-//       public SumStream(ViewStream stream, string[] output_columns, string[] groupby_columns, bool force_null_into_other_columns)
-//       {
-//          ViewStream rs = null;
-//          groupby_columns = groupby_columns ?? new string[] {};
-//          if (groupby_columns.Length == 0)
-//          {
-//             rs = new AddColumnsStream(stream, "fake_col=0");
-//             rs = new GroupByStream(rs, new MultiColumnSumGroupByEvaluator(output_columns, new string[] {"fake_col"}));
-//             rs = new ProjectStream(rs, "!fake_col");
-//          }
-//          else
-//          {
-//             rs = new GroupByStream(stream, new MultiColumnSumGroupByEvaluator(output_columns, groupby_columns));
-//          }
-//          if (force_null_into_other_columns)
-//          {
-//             List<string> valid_cols = new List<string>(output_columns);
-//             valid_cols.AddRange(groupby_columns);
-//             rs = new MapStream(rs, new NullMapper(valid_cols.ToArray()));
-//          }
-//          mySetRealSource(rs);
-//       }
+        public SumStream(ViewStream stream, string[] output_columns, string[] groupby_columns, bool force_null_into_other_columns) {
+            ViewStream rs = null;
+            groupby_columns = groupby_columns ?? new string[] { };
+            if (groupby_columns.Length == 0) {
+                // rs = new AddColumnsStream(stream, "fake_col=0");
+                // rs = new GroupByStream(rs, new MultiColumnSumGroupByEvaluator(output_columns, new string[] { "fake_col" }));
+                // rs = new ProjectStream(rs, "!fake_col");
+            } else {
+                rs = new GroupByStream(stream, new MultiColumnSumGroupByEvaluator(output_columns, groupby_columns));
+            }
+            if (force_null_into_other_columns) {
+                List<string> valid_cols = new List<string>(output_columns);
+                valid_cols.AddRange(groupby_columns);
+                rs = new MapStream(rs, new NullMapper(valid_cols.ToArray()));
+            }
+            mySetRealSource(rs);
+        }
 
-//    public SumStream (ViewStream stream, string outputCol)
-//    : this (new AddColumnsStream (stream, "fakeCol=0"), outputCol, "fakeCol")
-//    {
-//    }
-// }
+        public SumStream(ViewStream stream, string outputCol)
+        : this(new AddColumnsStream(stream, "fakeCol=0"), outputCol, "fakeCol") {
+        }
+    }
 
-// public class IntSumStream : ViewStream
-// {
-//    public IntSumStream (ViewStream stream, string spaceSeparatedOutputCols, string spaceSeparatedGroupByCols)
-//    {
-//       string[] outputCols = spaceSeparatedOutputCols.Split(' ');
-//       string[] groupByCols = spaceSeparatedGroupByCols.Split(' ');
-//       mySetRealSource(new GroupByStream(stream,
-//                                         outputCols.Length == 1 ? new SumGroupByEvaluator<int>(outputCols[0], groupByCols) as IGroupByEvaluator:
-//                                         new MultiColumnSumGroupByEvaluator<int>(spaceSeparatedOutputCols, spaceSeparatedGroupByCols)));
-//    }
+    public class IntSumStream : ViewStream {
+        public IntSumStream(ViewStream stream, string spaceSeparatedOutputCols, string spaceSeparatedGroupByCols) {
+            string[] outputCols = spaceSeparatedOutputCols.Split(' ');
+            string[] groupByCols = spaceSeparatedGroupByCols.Split(' ');
+            mySetRealSource(new GroupByStream(stream,
+                                              outputCols.Length == 1 ? new SumGroupByEvaluator<int>(outputCols[0], groupByCols) as IGroupByEvaluator :
+                                              new MultiColumnSumGroupByEvaluator<int>(spaceSeparatedOutputCols, spaceSeparatedGroupByCols)));
+        }
 
-// }
+    }
 
 
-//    public class SumStream<T> : ViewStream
-//    {
-//       public SumStream(ViewStream stream, string outputCol, string spaceSeparatedInputCols)
-//       {
-//          string[] inputCols = spaceSeparatedInputCols.Split(' ');
-//          mySetRealSource(new GroupByStream(stream,
-//                                              new SumGroupByEvaluator<T>(outputCol, inputCols)));
-//       }
-//    }
-// }
+    public class SumStream<T> : ViewStream {
+        public SumStream(ViewStream stream, string outputCol, string spaceSeparatedInputCols) {
+            string[] inputCols = spaceSeparatedInputCols.Split(' ');
+            mySetRealSource(new GroupByStream(stream,
+                                                new SumGroupByEvaluator<T>(outputCol, inputCols)));
+        }
+    }
+}

src/DataStreamSuite/DataStream/Primitives/InterRow/RowDiffStream.cs

@@ -0,0 +1,79 @@
+using BCG;
+
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+using ZstdSharp.Unsafe;
+
+namespace bts {
+    public class RowDiffStream : ViewStream {
+        private ViewStream _vs;
+        private readonly string _order_col, _col_1, _col_2;
+        private readonly int _diff;
+        private IBlueTableSchema _out_schema;
+        private readonly string _diff_col_name;
+        public RowDiffStream(ViewStream vs, string order_col, string col_1, string col_2, int diff, string diff_col_name) {
+            _vs = vs;
+            _order_col = order_col;
+            _col_1 = col_1;
+            _col_2 = col_2;
+            _diff = diff;
+            _diff_col_name = diff_col_name;
+        }
+
+        private string _diff_col_name_perc {
+            get {
+                return $"{_diff_col_name}_percentage";
+            }
+        }
+
+        protected override void myOnFirstSubscriber() {
+            _vs.onChange += _handle_vs;
+        }
+
+        protected override void myOnLastSubscriber() {
+            _vs.onChange -= _handle_vs;
+        }
+
+        private void _handle_vs(object dp_obj) {
+            var dp = dp_obj as DataPacket;
+            IBlueRowCollection nrows = dp.newRows;
+            _out_schema = BlueDataUtility.add_column(nrows.schema, _diff_col_name, typeof(double));
+            _out_schema = BlueDataUtility.add_column(_out_schema, _diff_col_name_perc, typeof(double));
+            List<IBlueRow> row_list = new List<IBlueRow>();
+            foreach (IBlueRow r in nrows)
+                row_list.Add(r);
+            //OrderBy sorts in ascedning order
+            var sorted_rows = row_list.OrderBy(r => r[_order_col]).ToList();
+            var sorted_row_array = sorted_rows.ToArray();
+            // reverse it to make it descending    
+            sorted_rows.Reverse();
+            //sort rows so we can do the diff
+            OrderedBlueTable rv = new OrderedBlueTable(_out_schema);
+            int i = 0;
+            foreach (IBlueRow r in sorted_rows) {
+                MutableBlueRow nr = new MutableBlueRow(_out_schema, r);
+                //So, in the expression "x - y," where y is subtracted from x, x is the minuend, and y is the subtrahend.
+                // we assume x - y, and name variables like that
+                double x = r.get<double>(_col_1);
+                int y_row_idx = i + _diff;
+                double diff = System.Double.NaN;
+                double perc = System.Double.NaN;
+                if (y_row_idx < sorted_rows.Count()) {
+                    var y = sorted_rows[y_row_idx].get<double>(_col_2);
+                    diff = x - y;
+                    perc = 100.0 * diff / y;
+                }
+                nr.setValue(_diff_col_name, diff);
+                nr.setValue(_diff_col_name_perc, perc);
+                rv.addRow(nr);
+                i++;
+            }
+
+            var dp_out = BlueDataUtility.build_dp_inc(new_rows: rv, myLastValue as DataPacket, true);
+            myFireEvent(dp_out);
+
+        }
+    }
+}

src/DataStreamSuite/DataStream/Primitives/Join/NonIncremental/NonIncJoinStream.cs

@@ -8,6 +8,7 @@ using mbts.spark;
 
 namespace BCG
 {
+   [DataStreamUserRespresentation("fastJoin")]
    public class NonIncJoinStream : ViewStream, BCG.Utilities.General.IWorker
    {
       private readonly NonIncJoinSpec[] _join_specs;
@@ -23,7 +24,7 @@ namespace BCG
 
       public NonIncJoinStream(ViewStream left, string left_join_cols, string left_proj,
                               ViewStream right, string right_join_cols, string right_proj)
-         : this(new Triplet<ViewStream, string, string>[] 
+         : this(new Triplet<ViewStream, string, string>[]
                {
                   new Triplet<ViewStream, string, string> (left, left_join_cols, left_proj),
                   new Triplet<ViewStream, string, string> (right, right_join_cols, right_proj)
@@ -31,7 +32,7 @@ namespace BCG
       { }
 
       public NonIncJoinStream(params Triplet<ViewStream, string, string>[] join_specs)
-         : this (NonIncJoinSpec.from_triplet (join_specs), null, 0)
+         : this(NonIncJoinSpec.from_triplet(join_specs), null, 0)
       { }
 
       public NonIncJoinStream(ViewStreamDatabase vsd, INonIncJoinInlineMapper output_mapper, int throttles_ms,
@@ -102,8 +103,8 @@ namespace BCG
          {
             List<ColumnInfo> cis = new List<ColumnInfo>(new ColumnInfo[] { new ColumnInfo("id", 0, typeof(int)) });
             foreach (NonIncJoinBookkeeper d in _book_keeping_data)
-               d.constribute_cols_to_schema (cis);
-            _output_schema = new BlueTableSchema ("NonIncJoinStream", cis.ToArray());
+               d.constribute_cols_to_schema(cis);
+            _output_schema = new BlueTableSchema("NonIncJoinStream", cis.ToArray());
          }
       }
 

src/DataStreamSuite/DataStream/Primitives/KeyValue/KeyValueToRelationalStream.cs

@@ -0,0 +1,31 @@
+namespace BCG {
+    using System.Collections.Generic;
+
+    public class KeyValueToRelationalStream : ViewStream {
+        private readonly ViewStream _kv_str;
+        private readonly string _doc_id_col, _key_col, _val_col;
+        public KeyValueToRelationalStream(ViewStream kv_str, string doc_id_col, string key_col, string val_col) {
+            _kv_str = kv_str;
+            _doc_id_col = doc_id_col;
+            _key_col = key_col;
+            _val_col = val_col;
+        }
+
+        protected override void myOnFirstSubscriber() {
+            _kv_str.onChange += _on_str_update;
+        }
+
+        protected override void myOnLastSubscriber() {
+            _kv_str.onChange -= _on_str_update;
+        }
+
+        private void _on_str_update(object dp_obj) {
+            DataPacket dp = dp_obj as DataPacket;
+            var rows = dp.newRows;
+            var rv = BlueDataUtility.keyvalue_to_relational<string>(rows, _doc_id_col, _key_col, _val_col);
+            var dp_out = BlueDataUtility.build_dp_inc(rv, myLastValue as DataPacket, true);
+            myFireEvent(dp_out);
+        }
+
+    }
+}

src/DataStreamSuite/DataStream/Primitives/Misc/DebugStream.cs

@@ -0,0 +1,48 @@
+
+
+using System;
+
+namespace BCG {
+   // Keeps adding changing rows to the stream, hence preserving the history
+   // and creating a time series, for example this can be used to make bbo updates
+   // into a time series of prices/qty 
+   public class DebugStream : ViewStream {
+
+      private ViewStream _stream;
+      private IBlueRowCollection _last_recv_rows = null;
+
+      public DebugStream(ViewStream stream) {
+         _stream = stream;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _stream.onChange += new ChangeDelegate(_onstream_change);
+      }
+      protected override void myOnLastSubscriber() {
+         _stream.onChange -= new ChangeDelegate(_onstream_change);
+      }
+
+      private void _onstream_change(object o) {
+         DataPacket dp = o as DataPacket;
+         BlueDataUtility.validate_table_schema(dp.newRows);
+         BlueDataUtility.validate_table_schema(dp.addedRows);
+         if (_last_recv_rows == null) {
+            _last_recv_rows = dp.newRows;
+         } else {
+            //schema 
+            bts.Log.assert(BlueDataUtility.compareSchemas(_last_recv_rows.schema, dp.newRows.schema));
+            bts.Log.assert(BlueDataUtility.compareSchemas(_last_recv_rows.schema, dp.addedRows.schema));
+            bts.Log.assert(BlueDataUtility.compareSchemas(_last_recv_rows.schema, dp.deletedRows.schema));
+            foreach (IBlueRow r in dp.deletedRows) {
+               bts.Log.assert(_last_recv_rows.containsID(r.get<int>("id")));
+            }
+            foreach (IBlueRow r in dp.addedRows) {
+               bts.Log.assert(dp.newRows.containsID(r.get<int>("id")));
+            }
+            _last_recv_rows = dp.newRows;
+         }
+         myFireEvent(o);
+
+      }
+   }
+}

src/DataStreamSuite/DataStream/Primitives/Misc/TimeSeriesStream.cs

@@ -0,0 +1,53 @@
+using Google.Protobuf.WellKnownTypes;
+
+using System;
+using BCG.Utilities.General;
+
+namespace BCG {
+   // Keeps adding changing rows to the stream, hence preserving the history
+   // and creating a time series, for example this can be used to make bbo updates
+   // into a time series of prices/qty 
+   public class TimeSeriesStream : ViewStream {
+      private BlueTable _table;
+      private ViewStream _stream;
+      private int _id = 0;
+
+      public TimeSeriesStream(ViewStream stream) {
+         _stream = stream;
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _stream.onChange += new ChangeDelegate(_onstream_change);
+      }
+      protected override void myOnLastSubscriber() {
+         _stream.onChange -= new ChangeDelegate(_onstream_change);
+      }
+
+
+      private void _onstream_change(object o) {
+         DataPacket dp = o as DataPacket;
+         DateTime now = DateTime.Now;
+         if (_table == null) {
+            IBlueTableSchema schema = new BlueTableSchema(dp.newRows.schema.columnInfo, dp.newRows.schema.tableName);
+            schema = schema.add_columns(Tuple.Create(typeof(DateTime), "timestamp"));
+            _table = new BlueTable(schema);
+         }
+         BlueTable added_rows = new BlueTable(_table.schema);
+         foreach (IBlueRow r in dp.addedRows) {
+            MutableBlueRow ar = new MutableBlueRow(_table.schema, r);
+            ar.setValue("timestamp", now);
+            ar.setValue("id", _id++);
+            added_rows.addRow(ar);
+         }
+         _table.addRows(added_rows);
+         myFireEvent(new DataPacket(_table, added_rows, new BlueTable(_table.schema)));
+
+      }
+   }
+
+
+
+}
+
+
+

src/DataStreamSuite/DataStream/Primitives/Misc/WebScrapingStream.cs

@@ -0,0 +1,121 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Security.Cryptography.X509Certificates;
+
+using BCG;
+using BCG.Utilities.General;
+
+using HtmlAgilityPack;
+
+namespace BCG {
+    class Program {
+        static void Main() {
+            string url = "http://quotes.toscrape.com";
+            List<string> quotes = ScrapeQuotes(url);
+
+            Console.WriteLine("Quotes from http://quotes.toscrape.com:");
+            foreach (var quote in quotes) {
+                Console.WriteLine(quote);
+            }
+        }
+
+        static List<string> ScrapeQuotes(string url) {
+            List<string> quotes = new List<string>();
+
+            // Create a new HtmlWeb instance
+            HtmlWeb web = new HtmlWeb();
+
+            try {
+                // Load the HTML document from the specified URL
+                HtmlDocument document = web.Load(url);
+
+                // Extract quotes from the HTML document
+                var quoteNodes = document.DocumentNode.SelectNodes("//span[@class='text']");
+                if (quoteNodes != null) {
+                    foreach (var quoteNode in quoteNodes) {
+                        string quote = quoteNode.InnerText.Trim();
+                        quotes.Add(quote);
+                    }
+                }
+            } catch (Exception ex) {
+                Console.WriteLine($"Error: {ex.Message}");
+            }
+
+            return quotes;
+        }
+    }
+
+    public class WebScapperStream : ViewStream, IWorker {
+        private readonly string _url;
+        private readonly string _xpath;
+        private readonly ViewStreamDatabase _vsd;
+        private IDictionary<string, int> _line_id_map = new Dictionary<string, int>();
+        private readonly IBlueTableSchema _schema;
+
+        public WebScapperStream()
+        :
+        this("http://quotes.toscrape.com", "//span[@class='text']", ViewStreamDatabase.instance) { }
+        public WebScapperStream(string url, string xpath)
+        : this(url, xpath, ViewStreamDatabase.instance) { }
+        public WebScapperStream(string url, string xpath, ViewStreamDatabase vsd) {
+            bts.Log.Gen.info($"WebScapperStream cons url: {url} xpath: {xpath}");
+            _schema = BlueDataUtility.form_schema($"{url}_{xpath}",
+                                                Tuple.Create("id", TypeCode.Int32),
+                                                Tuple.Create("url", TypeCode.UInt32),
+                                                Tuple.Create("line", TypeCode.String));
+            _url = url;
+            _xpath = xpath;
+            _vsd = vsd;
+        }
+
+        protected override void myOnFirstSubscriber() {
+            MasterWorker.getInstance(false).addWorker(this, TimeSpan.FromSeconds(1));
+        }
+
+        protected override void myOnLastSubscriber() {
+            MasterWorker.getInstance(false).removeWorker(this);
+        }
+
+        public void doWork() {
+            var lines = scrape_lines(_url, _xpath);
+            Func<string, int> get_id = (line) => {
+                int rv = 0;
+                if (!_line_id_map.TryGetValue(line, out rv))
+                    _line_id_map.Add(line, _line_id_map.Count);
+                return rv;
+            };
+            BlueTable nrows = new BlueTable(_schema);
+            foreach (var l in lines) {
+                bts.Log.Gen.info($"line: {l}");
+                var id = get_id(l);
+                BlueRow nr = new BlueRow(_schema, get_id(l), _url, l);
+                nrows.addRow(nr);
+            }
+            var dp = BlueDataUtility.build_dp_inc(nrows, myLastValue as DataPacket, true);
+            myFireEvent(dp);
+        }
+
+        static List<string> scrape_lines(string url, string xpath) {
+            List<string> quotes = new List<string>();
+            // Create a new HtmlWeb instance
+            HtmlWeb web = new HtmlWeb();
+            try {
+                // Load the HTML document from the specified URL
+                HtmlDocument document = web.Load(url);
+                // Extract quotes from the HTML document
+                var quote_nodes = document.DocumentNode.SelectNodes(xpath);
+                if (quote_nodes != null) {
+                    foreach (var qn in quote_nodes) {
+                        string quote = qn.InnerText.Trim();
+                        quotes.Add(quote);
+                    }
+                }
+            } catch (Exception ex) {
+                Console.WriteLine($"Error: {ex.Message}");
+            }
+
+            return quotes;
+        }
+    }
+}

src/DataStreamSuite/DataStream/Primitives/MongoDB/MongoDBStream.cs

@@ -0,0 +1,212 @@
+using System;
+using System.Collections.Generic;
+using MongoDB.Driver;
+using MongoDB.Bson;
+using BCG;
+using BCG.Utilities.General;
+using ZstdSharp.Unsafe;
+using System.Runtime.CompilerServices;
+using mbts.spark;
+
+
+namespace BCG {
+    [DataStreamUserRespresentation("mongodb_sql")]
+    public class MongoDBSQLStream : ViewStream, IWorker {
+        private ViewStreamDatabase _vsd;
+        private readonly string _connection_string, _db_name, _collection_name;
+        private MongoClient _client;
+        private BlueTable _table;
+
+        // Access the database
+        private IMongoDatabase _database;
+        private IDictionary<string, int> _id_map = new Dictionary<string, int>();
+        // mongodb://192.168.1.80:27017
+
+        public MongoDBSQLStream(string connection_string, string db_name, string collection_name)
+        : this(connection_string, db_name, collection_name, ViewStreamDatabase.instance) {
+
+        }
+        public MongoDBSQLStream(string connection_string, string db_name, string collection_name, ViewStreamDatabase vsd) {
+            bts.Log.Gen.info($"MongoDBStream constructed connection_string: {connection_string} " +
+                                    $"db_name: {db_name}");
+            _connection_string = connection_string;
+            _db_name = db_name;
+            _collection_name = collection_name;
+            _vsd = vsd;
+            _client = new MongoClient(_connection_string);
+            _database = _client.GetDatabase(_db_name);
+        }
+
+        protected override void myOnFirstSubscriber() {
+            MasterWorker.getInstance(false).addWorker(this, TimeSpan.FromSeconds(1));
+        }
+
+        protected override void myOnLastSubscriber() {
+            MasterWorker.getInstance(false).removeWorker(this);
+        }
+
+        public void doWork() {
+            _read_mogodb();
+        }
+
+        private void _read_mogodb() {
+            HighPerformanceTimer timer = new HighPerformanceTimer();
+            timer.start();
+            // Access the collection
+            IMongoCollection<BsonDocument> collection = _database.GetCollection<BsonDocument>(name: _collection_name);
+
+            // Fetch all documents from the collection
+            var documents = collection.Find(Builders<BsonDocument>.Filter.Empty).ToCursor();
+            _table = _table == null ? null : new BlueTable(_table.schema);
+            // Iterate through the documents and print values
+            foreach (var document in documents.ToEnumerable()) {
+                bts.Log.Gen.info($"document: {document} json: {document.ToJson()}");
+                if (_table == null) {
+                    _init_table(document);
+                }
+                _add_row(document);
+            }
+            timer.stop();
+            bts.Log.Gen.info($"MongoDBStream time to read {_collection_name} {timer.lastIntervalTime} msecs");
+            timer.start();
+            var dp = BlueDataUtility.build_dp_inc(_table, myLastValue == null ? null : myLastValue as DataPacket, true);
+            timer.stop();
+            bts.Log.Gen.info($"MongoDBStream time to compare tables :{timer.lastIntervalTime} msecs");
+            if (dp.addedRows.Count == 0 && dp.deletedRows.Count == 0)
+                return;
+            myFireEvent(dp);
+        }
+
+        private void _init_table(BsonDocument doc_row) {
+            bts.Log.assert(_table == null);
+            List<ColumnInfo> cis = new List<ColumnInfo>();
+            cis.Add((new ColumnInfo("id", 0, typeof(Int32))));
+            foreach (var n in doc_row.Names) {
+                cis.Add(new ColumnInfo(n, cis.Count, typeof(string)));
+            }
+            IBlueTableSchema schema = new BlueTableSchema(cis.ToArray(), _collection_name);
+            _table = new BlueTable(schema);
+        }
+
+        private void _add_row(BsonDocument doc) {
+            var key_val = doc["_id"];
+            var key = key_val.ToString();
+            int id;
+            if (!_id_map.TryGetValue(key, out id)) {
+                id = _id_map.Count;
+                _id_map.Add(key, id);
+            }
+            MutableBlueRow nr = new MutableBlueRow(_table.schema);
+            nr.setValue("id", id);
+            foreach (var n in doc.Names) {
+                var val = doc[n].ToString();
+                nr.setValue(n, val);
+            }
+            _table.addRow(nr);
+        }
+    }
+
+    [DataStreamUserRespresentation("mongodb")]
+    public class MongoDBStream : ViewStream, IWorker {
+        private ViewStreamDatabase _vsd;
+        private readonly string _connection_string, _db_name, _collection_name;
+        private MongoClient _client;
+        private BlueTable _table;
+
+        // Access the database
+        private IMongoDatabase _database;
+        private IDictionary<string, int> _id_map = new Dictionary<string, int>();
+        // mongodb://192.168.1.80:27017
+
+        public MongoDBStream(string connection_string, string db_name, string collection_name)
+        : this(connection_string, db_name, collection_name, ViewStreamDatabase.instance) {
+
+        }
+        public MongoDBStream(string connection_string, string db_name, string collection_name, ViewStreamDatabase vsd) {
+            bts.Log.Gen.info($"MongoDBStream constructed connection_string: {connection_string} " +
+                                    $"db_name: {db_name}");
+            _connection_string = connection_string;
+            _db_name = db_name;
+            _collection_name = collection_name;
+            _vsd = vsd;
+            _client = new MongoClient(_connection_string);
+            _database = _client.GetDatabase(_db_name);
+        }
+
+        protected override void myOnFirstSubscriber() {
+            MasterWorker.getInstance(false).addWorker(this, TimeSpan.FromSeconds(1));
+        }
+
+        protected override void myOnLastSubscriber() {
+            MasterWorker.getInstance(false).removeWorker(this);
+        }
+
+        public void doWork() {
+            _read_mogodb();
+        }
+
+        private void _read_mogodb() {
+            HighPerformanceTimer timer = new HighPerformanceTimer();
+            timer.start();
+            // Access the collection
+            IMongoCollection<BsonDocument> collection = _database.GetCollection<BsonDocument>(name: _collection_name);
+
+            // Fetch all documents from the collection
+            var documents = collection.Find(Builders<BsonDocument>.Filter.Empty).ToCursor();
+            _table = _table == null ? null : new BlueTable(_table.schema);
+            // Iterate through the documents and print values
+            foreach (var document in documents.ToEnumerable()) {
+                bts.Log.Gen.info($"document: {document} json: {document.ToJson()}");
+                if (_table == null) {
+                    _init_table(document);
+                }
+                _add_doc(document);
+            }
+            timer.stop();
+            bts.Log.Gen.info($"MongoDBStream time to read {_collection_name} {timer.lastIntervalTime} msecs");
+            timer.start();
+            var dp = BlueDataUtility.build_dp_inc(_table, myLastValue == null ? null : myLastValue as DataPacket, true);
+            timer.stop();
+            bts.Log.Gen.info($"MongoDBStream time to compare tables :{timer.lastIntervalTime} msecs");
+            if (dp.addedRows.Count == 0 && dp.deletedRows.Count == 0)
+                return;
+            myFireEvent(dp);
+        }
+
+        private void _init_table(BsonDocument doc_row) {
+            bts.Log.assert(_table == null);
+            var schema = BlueDataUtility.form_schema($"{_database}_{_table}",
+            Tuple.Create("id", TypeCode.Int32),
+            Tuple.Create("doc_id", TypeCode.String),
+            Tuple.Create("key", TypeCode.String),
+            Tuple.Create("value", TypeCode.String));
+            _table = new BlueTable(schema);
+        }
+
+        private void _add_doc(BsonDocument doc) {
+            var doc_id_bson = doc["_id"];
+            var doc_id = doc_id_bson.ToString();
+            Func<string, string, int> get_id = (string doc_id, string key) => {
+                string hash_key = $"{doc_id}_{key}";
+                int id = 0;
+                if (!_id_map.TryGetValue(hash_key, out id)) {
+                    id = _id_map.Count;
+                    _id_map.Add(hash_key, id);
+                }
+                return id;
+            };
+            foreach (var n in doc.Names) {
+                string key = n;
+                var id = get_id(doc_id, key);
+                MutableBlueRow nr = new MutableBlueRow(_table.schema);
+                var val = doc[n].ToString();
+                nr.setValue("id", id);
+                nr.setValue("doc_id", doc_id);
+                nr.setValue("key", key);
+                nr.setValue("value", val);
+                _table.addRow(nr);
+            }
+        }
+    }
+
+}

src/DataStreamSuite/DataStream/Primitives/SideEffectStreams/CSVSaverStream.cs

@@ -6,7 +6,7 @@ using BCG.Utilities;
 
 namespace BCG
 {
-   [DataStreamUserRespresentation("csvSaver")]
+   [DataStreamUserRespresentation("CSVSaver")]
    public class CSVSaverStream : ViewStream, ISideEffectStream
    {
       private IBlueTableSchema myResultSchema = new BlueTableSchema("CSVResult", new ColumnInfo("id", 0, typeof(int)),

src/DataStreamSuite/DataStream/Primitives/SideEffectStreams/SchemaGuesserStream.cs

@@ -0,0 +1,34 @@
+using BCG;
+
+namespace bts {
+    public class SchemaGuesserStream : ViewStream {
+
+        private IBlueRowCollection _rows = null;
+        private ViewStream _vs;
+        public SchemaGuesserStream(ViewStream vs) {
+            _vs = vs;
+        }
+
+        protected override void myOnFirstSubscriber() {
+            _vs.onChange += _on_data;
+        }
+        protected override void myOnLastSubscriber() {
+            _vs.onChange -= _on_data;
+        }
+
+        private void _on_data(object obj) {
+            DataPacket dp = obj as DataPacket;
+            if (_rows == null) {
+                _rows = BlueDataUtility.get_typed_table(dp.newRows);
+            }
+            var dp_out = BlueDataUtility.build_dp_inc(_rows, myLastValue as DataPacket);
+            myFireEvent(dp_out);
+
+
+        }
+
+
+
+
+    }
+}

src/DataStreamSuite/DataStream/Primitives/Sort/SortRow.cs

@@ -1,115 +1,107 @@
-// using System;
-// using System.Collections;
-// using BCG.Utilities;
-// using BCG.Evaluator.SortExpression;
-
-
-// namespace BCG
-// {
-//    public class SortRow : IComparable, IBlueRow
-//    {
-//       private IBlueRow myRow;
-//       private IEnumerable myColumns;
-//       private IComparer myComparer;
-
-//       public SortRow (IBlueRow row, SortExpression sortExpression)
-//       {
-//          myRow = row;
-//          myColumns = sortExpression.columns;
-//       }
-
-//       public SortRow (IBlueRow row, IEnumerable columns)
-//       {
-//          myRow = row;
-//          myColumns = columns;
-//       }
-
-//       public SortRow (IBlueRow row, IComparer comparer)
-//       {
-//          myRow = row;
-//          myComparer = comparer;
-//       }
-
-//       public IBlueRow internal_row { get { return myRow; } }
-
-//       #region IComparable method
-//       public int CompareTo (object obj)
-//       {  
-//          IBlueRow otherRow = (IBlueRow)obj;
-//          if (myComparer == null)
-//          {
-//             foreach (SortExpression.ColumnCriteria cc in myColumns)
-//             {
-//                int retVal = myIsNull (this[cc.columnName]) ?
-//                   myIsNull (otherRow[cc.columnName]) ? 0 : -1 :
-//                   myIsNull (otherRow[cc.columnName]) ? 1 : ((IComparable)this[cc.columnName]).CompareTo (otherRow[cc.columnName]);
-//                retVal *= cc.ascending ? 1 : -1;
-//                if (retVal != 0)
-//                   return retVal;
-//             }
-//             return 0;
-//          }
-//          else
-//             return myComparer.Compare (this, otherRow);
-//       }
-//       #endregion
-
-//       #region IBlueRow members
-//       public IBlueTableSchema schema{get{return myRow.schema;}}
-//       #endregion
-
-//       #region ICollection members
-//       public int Count {get{return myRow.Count;}}
-
-//       public bool IsSynchronized {get{return false;}}
-
-//       public object SyncRoot {get{return this;}}
-
-//       public void CopyTo (Array array, int index) {myRow.CopyTo (array, index);}
-//       #endregion
-
-//       #region IDictionary members
-//       public bool IsFixedSize {get{return true;}}
-
-//       public bool IsReadOnly {get{return true;}}
-
-//       /// <summary>
-//       /// The key can either be the string corrsponding to the column name or
-//       /// the order of the column
-//       /// </summary>
-//       public object this [object key]
-//       {
-//          get
-//          {
-//             if (key is string)
-//                return this[(string)key];
-//             return this[(int)key];
-//          }
-//          set {throw new NotSupportedException ("The IBlueRow is readonly");}
-//       }
-
-//       public object this [int index]   {get{return myRow[index];}}
-
-//       public object this [string colName] {get{return myRow[colName];}}
-
-//       public ICollection Keys{get{return myRow.Keys;}}
-
-//       public ICollection Values{get{return myRow.Values;}}
-
-//       public void Add (object key, object value)   {throw new NotSupportedException ("The IBlueRow is readonly");}
-
-//       public void Clear () {throw new NotSupportedException ("The IBlueRow is readonly");}
-
-//       public bool Contains (object key){return myRow.Contains (key);}
-
-//       IDictionaryEnumerator IDictionary.GetEnumerator() {return myRow.GetEnumerator();}
-
-//       IEnumerator IEnumerable.GetEnumerator () {return myRow.GetEnumerator();}
-
-//       public void Remove (object key) {throw new NotSupportedException ("The IBlueRow is readonly");}
-//       #endregion
-
-//       private bool myIsNull (object o) {return o == null || o is DBNull;}
-
-//    }
-// }
+using Bts.ColumnSortExpressions;
+
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Linq;
+
+namespace BCG;
+
+public class SortRow : IComparable, IBlueRow {
+   readonly IBlueRow row;
+   readonly IEnumerable<ColumnSortExpression>? columns;
+   readonly IComparer? comparer;
+
+   public SortRow(IBlueRow row, IList<ColumnSortExpression> columns) {
+      this.row = row;
+      this.columns = columns;
+   }
+
+   public SortRow(IBlueRow row, IComparer comparer) {
+      this.row = row;
+      this.comparer = comparer;
+   }
+
+   public IBlueRow internal_row { get { return row; } }
+
+   #region IComparable method
+   public int CompareTo(object? obj) {
+      if (obj is not IBlueRow otherRow) {
+         throw new ArgumentException(
+            $"Expected obj to be of type {typeof(IBlueRow)} (actually {obj?.GetType()})",
+            nameof(obj));
+      }
+      if (comparer is not null) {
+         return comparer.Compare(this, otherRow);
+      }
+      return columns.empty_if_null().Select(Compare).FirstOrDefault(c => c != 0);
+      int Compare(ColumnSortExpression col) {
+         var otherVal = otherRow[col.Name];
+         int rv = myIsNull(this[col.Name]) ?
+            (myIsNull(otherVal) ? 0 : -1) :
+            (myIsNull(otherVal) ? 1 : ((IComparable)this[col.Name]).CompareTo(otherVal));
+         rv *= col.IsAscending ? 1 : -1;
+         return rv;
+      }
+   }
+   #endregion
+
+   #region IBlueRow members
+   public IBlueTableSchema schema { get { return row.schema; } }
+   #endregion
+
+   #region ICollection members
+   public int Count { get { return row.Count; } }
+
+   public bool IsSynchronized { get { return false; } }
+
+   public object SyncRoot { get { return this; } }
+
+   public void CopyTo(Array array, int index) { row.CopyTo(array, index); }
+   #endregion
+
+   #region IDictionary members
+   public bool IsFixedSize { get { return true; } }
+
+   public bool IsReadOnly { get { return true; } }
+
+   /// <summary>
+   /// The key can either be the string corrsponding to the column name or
+   /// the order of the column
+   /// </summary>
+   public object this[object key] {
+      get {
+         if (key is string)
+            return this[(string)key];
+         return this[(int)key];
+      }
+      set { throw new NotSupportedException("The IBlueRow is readonly"); }
+   }
+
+   public object this[int index] => row[index];
+
+   public object this[string colName] => row[colName];
+
+   public ICollection Keys => row.Keys;
+
+   public ICollection Values => row.Values;
+
+   public bool Contains(object key) => row.Contains(key);
+
+   void IDictionary.Add(object key, object? value) =>
+      throw new NotSupportedException("The IBlueRow is readonly");
+
+   void IDictionary.Clear() =>
+      throw new NotSupportedException("The IBlueRow is readonly");
+
+   IDictionaryEnumerator IDictionary.GetEnumerator() { return row.GetEnumerator(); }
+
+   IEnumerator IEnumerable.GetEnumerator() { return row.GetEnumerator(); }
+
+   public void Remove(object key) { throw new NotSupportedException("The IBlueRow is readonly"); }
+   #endregion
+
+   bool myIsNull(object? o) =>
+      o is null || o == null || o is DBNull;
+
+}

src/DataStreamSuite/DataStream/Primitives/Sort/SortStream.cs

@@ -1,129 +1,99 @@
-// using System;
-// using System.Collections;
-// using BCG.Evaluator.SortExpression;
+using Bts.ColumnSortExpressions;
 
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
 
-// namespace BCG
-// {
-// 	/// <summary>
-// 	/// Defines a Sort stream, with performance of O(n) for all the increments. It uses simple merge sort
-// 	/// to merge the additions to the accumulates table
-// 	/// </summary>
-// 	public class SortStream : ViewStream
-// 	{
-//       private ViewStream myStream;
-//       private IEnumerable mySortCols;
-//       private IComparer myComparer;
-//       private DataPacket myLastFiredPacket;
-//       private DataPacket myLastRecievedPacket;
+namespace BCG;
 
-//       public SortStream (ViewStream stream, string sortExpression)
-//       {
-//          myStream = stream;
-//          mySetSortExpression (sortExpression);
-//       }
+/// <summary>
+/// Defines a Sort stream, with performance of O(n) for all the increments. It uses simple merge sort
+/// to merge the additions to the accumulates table
+/// </summary>
+public class SortStream : ViewStream {
+   ViewStream stream;
+   IList<ColumnSortExpression> sortCols;
+   IComparer? comparer;
+   DataPacket? lastFiredPacket;
+   DataPacket? lastReceivedPacket;
 
-//       public SortStream (ViewStream vs, string colName, bool isAsc)
-//       {
-//          myStream = vs;
-//          string sortExpression = isAsc ? "+" + colName : "-" + colName;
-//          mySetSortExpression (sortExpression);
-//       }
+   public SortStream(ViewStream stream, string sortExpression) {
+      this.stream = stream;
+      SortExpression = sortExpression;
+   }
 
-//       public SortStream (ViewStream vs, IComparer comparer)
-//       {
-//          myStream = vs;
-//          myComparer = comparer;
-//       }
+   public SortStream(ViewStream vs, string colName, bool isAsc) {
+      stream = vs;
+      SortExpression = isAsc ? "+" + colName : "-" + colName;
+   }
 
-//       public string sortExpression
-//       {
-//          set
-//          {
-//             myComparer = null;
-//             myLastFiredPacket = null;
-//             mySetSortExpression (value);   
-//             myChangeHandler (myLastRecievedPacket);
-//          }
-//       }
+   public SortStream(ViewStream stream, IComparer comparer) {
+      this.stream = stream;
+      this.comparer = comparer;
+      sortCols = Array.Empty<ColumnSortExpression>();
+   }
 
-//       public IComparer comparer
-//       {
-//          set
-//          {
-//             myComparer = value;
-//             myLastFiredPacket = null;
-//             myChangeHandler(myLastRecievedPacket);
-//          }
-//       }
+   [MemberNotNull(nameof(sortCols))]
+   public string SortExpression {
+      set {
+         comparer = null;
+         lastFiredPacket = null;
+         sortCols = ColumnSortExpressionInterpreter.Evaluate(value);
+         if (lastReceivedPacket is not null) {
+            myChangeHandler(lastReceivedPacket);
+         }
+      }
+   }
 
-//       private void mySetSortExpression (string sortExpression)
-//       {
-//          syntax parser = 
-//             new syntax();
-         
-//          mySortCols = ((SortExpression)
-//             parser.Parse (sortExpression)).columns;
-//       }
+   public IComparer Comparer {
+      set {
+         comparer = value;
+         lastFiredPacket = null;
+         if (lastReceivedPacket is not null) {
+            myChangeHandler(lastReceivedPacket);
+         }
+      }
+   }
 
-//       protected override void myOnFirstSubscriber()
-//       {
-//          myStream.onChange += new DataStream.ChangeDelegate (myChangeHandler); 
-//       }
+   public void myChangeHandlerTest(object o) =>
+      myChangeHandler(o);
 
-//       protected override void myOnLastSubscriber()
-//       {
-//          myInit ();
-//          myStream.onChange -= new DataStream.ChangeDelegate (myChangeHandler); 
-//       }
+   [MemberNotNull(nameof(lastFiredPacket))]
+   internal void myChangeHandler(object o) {
+      lastReceivedPacket = (DataPacket)o;
+      // First callback, so we need to sort the whole table, this is the
+      // only time we will do that for all the other sorting operations would
+      // be sorting the increments and inserting them into the whole list
+      if (lastFiredPacket is null) {
+         lastFiredPacket = new() {
+            newRows = comparer is null ?
+               new SortedTable(lastReceivedPacket.newRows, sortCols) :
+               new SortedTable(lastReceivedPacket.newRows, comparer)
+         };
+         lastFiredPacket.addedRows = new OrderedBlueTable(lastFiredPacket.newRows);
+         lastFiredPacket.deletedRows = new BlueTable(lastFiredPacket.newRows.schema);
+         myFireEvent(lastFiredPacket.Clone());
+         return;
+      }
+      // Deletes
+      lastFiredPacket.deletedRows =
+         comparer == null ?
+         new SortedTable(lastReceivedPacket.deletedRows, sortCols) :
+         new SortedTable(lastReceivedPacket.deletedRows, comparer);
+      ((SortedTable)lastFiredPacket.newRows).deleteRows(lastFiredPacket.deletedRows);
+      // Adds
+      lastFiredPacket.addedRows = new BlueTable(lastReceivedPacket.addedRows);
+      ((SortedTable)lastFiredPacket.newRows).addRows(lastFiredPacket.addedRows);
+      myFireEvent(lastFiredPacket.Clone());
+   }
 
-//       internal void myChangeHandler (object o)
-//       {
-//          myLastRecievedPacket = (DataPacket)o;
-//          //first callback, so we need to sort the whole table, this is the
-//          //only time we will do that for all the other sorting operations would
-//          //be sorting the increments and inserting them into the whole list
-//          if (myLastFiredPacket == null)
-//          {
-//             myLastFiredPacket = new DataPacket ();
-//             myLastFiredPacket.newRows = 
-//                myComparer == null ?
-//                new SortedTable (myLastRecievedPacket.newRows, mySortCols) :
-//                new SortedTable (myLastRecievedPacket.newRows, myComparer);
-//             myLastFiredPacket.addedRows = new OrderedBlueTable(myLastFiredPacket.newRows);
-//             myLastFiredPacket.deletedRows = new BlueTable (myLastFiredPacket.newRows.schema);
-//             myFireEvent (myLastFiredPacket.Clone());
-//             return;
-//          }
-//          myHandleDeletes (myLastRecievedPacket);
-//          myHandleAdds (myLastRecievedPacket);
-//          myFireEvent (myLastFiredPacket.Clone());
-//       }
+   protected override void myOnFirstSubscriber() =>
+      stream.onChange += myChangeHandler;
 
-//       public void myChangeHandlerTest(object o)
-//       {
-//           myChangeHandler(o);
-//       }
-
-//       private void myHandleDeletes (DataPacket dp)
-//       {
-//          myLastFiredPacket.deletedRows = 
-//             myComparer == null ?
-//             new SortedTable (dp.deletedRows, mySortCols) :
-//             new SortedTable (dp.deletedRows, myComparer);
-//          ((SortedTable)(myLastFiredPacket.newRows)).deleteRows (myLastFiredPacket.deletedRows);
-//       }
-
-//       private void myHandleAdds (DataPacket dp)
-//       {
-//          myLastFiredPacket.addedRows = new BlueTable (dp.addedRows);
-//          ((SortedTable)(myLastFiredPacket.newRows)).addRows (myLastFiredPacket.addedRows);
-//       }
-
-//       private void myInit ()
-//       {
-//          myLastFiredPacket = null;
-//          myLastRecievedPacket = null;
-//       }
-// 	}
-// }
+   protected override void myOnLastSubscriber() {
+      lastFiredPacket = null;
+      lastReceivedPacket = null;
+      stream.onChange -= myChangeHandler;
+   }
+}

src/DataStreamSuite/DataStream/Primitives/Sort/SortedTable.cs

@@ -1,136 +1,108 @@
-// using System;
-// using System.Collections;
-// using BCG.Evaluator.SortExpression;
-
-// namespace BCG
-// {
-//    /// <summary>
-//    /// Represents an IBlueRowCollection with the rows sorted according to the
-//    /// 
-//    /// </summary>
-//    public class SortedTable : IBlueRowCollection 
-//    {
-//       private ArrayList myRows = new ArrayList ();
-//       private Hashtable myIndex = new Hashtable ();
-//       private IBlueTableSchema mySchema;
-//       private IEnumerable mySortCols;
-//       private IComparer myComparer;
-
-//       #region SortedTable method(s)
-//       public void addRows (IBlueRowCollection rows)
-//       {
-//          //requires merger of the addedRows to the already existing ones
-//          if (rows.Count == 0)
-//             //at times there are calls with 0 additions, in that case
-//             //we ofcourse need no processing
-//             return;
-//          SortedTable addedRows = 
-//             myComparer == null ? new SortedTable (rows, mySortCols) :
-//                new SortedTable (rows, myComparer);
-//          int addedRowsIndex = 0;
-//          SortRow newRow = addedRows.getRowByIndex (addedRowsIndex);
-//          for (int i = 0; i < myRows.Count; i ++)
-//             if (newRow.CompareTo(myRows[i]) <= 0)
-//             {
-//                myRows.Insert (i, newRow);
-//                myIndex[newRow["id"]] = newRow;
-//                if (++addedRowsIndex == addedRows.Count)
-//                   return;
-//                newRow = addedRows.getRowByIndex (addedRowsIndex);
-//             }
-//          if (addedRowsIndex < addedRows.Count)
-//             for (int i = addedRowsIndex; i < addedRows.Count; i++)
-//             {
-//                newRow = addedRows.getRowByIndex (i);
-//                myRows.Add (newRow);
-//                myIndex[newRow["id"]] = newRow;
-//             }
-//       }
-
-//       public void deleteRows (IBlueRowCollection deletedRows)
-//       {
-//          foreach (IBlueRow deletedRow in deletedRows)
-//          {
-//             IBlueRow row = (SortRow)myIndex[deletedRow["id"]];
-//             myRows.Remove (row);
-//             myIndex.Remove (row["id"]);
-//          }
-//       }
-
-//       public SortRow getRowByIndex (int index)  {return (SortRow)myRows[index];}
-//       #endregion
-
-//       #region Constructor(s)
-//       /// <summary>
-//       /// Sorts the rows using sortExpression as the sorting criteria
-//       /// </summary>
-//       /// <param name="rows">
-//       /// Rows to be inserted into the table
-//       /// </param>
-//       /// <param name="sortExpression">
-//       /// Sorting criteria
-//       /// </param>
-//       public SortedTable (IBlueRowCollection rows, SortExpression sortExpression)
-//       {
-//          mySortCols = sortExpression.columns;
-//          myConstructorHelper (rows);
-//       }
-
-//       public SortedTable (IBlueRowCollection rows, IEnumerable sortCols)
-//       {
-//          mySortCols = sortCols;
-//          myConstructorHelper (rows);
-//       }
-
-//       public SortedTable (IBlueRowCollection rows, IComparer comparer)
-//       {
-//          myComparer = comparer;
-//          myConstructorHelper (rows);
-//       }
-
-//       private void myConstructorHelper (IBlueRowCollection rows)
-//       {
-//          mySchema = rows.schema;
-//          foreach (IBlueRow row in rows)
-//          {
-//             SortRow newRow = 
-//                myComparer == null ?
-//                new SortRow (row, mySortCols) : new SortRow (row, myComparer);
-//             myRows.Add (newRow);
-//             myIndex[row["id"]] = newRow;
-//          }
-//          myRows.Sort ();
-//       }
-
-//       #endregion
-
-//       #region IBlueRowCollections members
-//       public IBlueRow this[int id] 
-//       {
-//          get
-//          {
-//             if (myIndex[id] == null)
-//                throw new BlueDataException ("ID " + id.ToString() + " does not exist in table " + mySchema.tableName);
-//             return (IBlueRow)myIndex[id];
-//          }
-//       }
-//       public IBlueTableSchema schema {get{return mySchema;}}
-
-//       public bool containsID (int id)  {return myIndex[id] != null;}
-
-//       #endregion
-
-//       #region ICollection members
-//       public IEnumerator GetEnumerator () {return myRows.GetEnumerator ();}
-
-//       public bool IsSynchronized {get{return false;}}
-
-//       public object SyncRoot {get{return this;}}
-
-//       public void CopyTo (Array array, int index){myRows.CopyTo (array, index);}
-
-//       public int Count{get{return myRows.Count;}}
-//          #endregion
-//    }
-
-// }
+using System;
+using System.Collections;
+using System.Collections.Generic;
+using System.Diagnostics.CodeAnalysis;
+
+using Bts.ColumnSortExpressions;
+
+namespace BCG;
+
+/// <summary>
+/// Represents an IBlueRowCollection with the rows sorted according to the
+/// </summary>
+public class SortedTable : IBlueRowCollection {
+   readonly List<SortRow> rows = new(0);
+   readonly Dictionary<int, IBlueRow> rowIndex = new(0);
+   readonly IList<ColumnSortExpression> sortCols = Array.Empty<ColumnSortExpression>();
+   readonly IComparer? comparer;
+
+   /// <summary>
+   /// Sorts the rows using sortExpression as the sorting criteria
+   /// </summary>
+   /// <param name="rows">Rows to be inserted into the table</param>
+   /// <param name="sortCols">Sorting criteria</param>
+   public SortedTable(IBlueRowCollection rows, IList<ColumnSortExpression> sortCols) {
+      this.sortCols = sortCols;
+      init(rows);
+   }
+
+   public SortedTable(IBlueRowCollection rows, IComparer comparer) {
+      this.comparer = comparer;
+      init(rows);
+   }
+
+   public int Count => rows.Count;
+   public bool IsSynchronized => false;
+   public IBlueTableSchema schema { get; private set; }
+   public object SyncRoot => this;
+   public IBlueRow this[int id] => rowIndex[id]
+      ?? throw new BlueDataException(
+         $"ID '{id}' does not exist in table '{schema?.tableName}'");
+
+   public void addRows(IBlueRowCollection rows) {
+      // Requires merger of the addedRows to the already existing ones
+      if (rows.Count == 0) {
+         // At times there are calls with 0 additions, in that case
+         // we of course need no processing
+         return;
+      }
+      SortedTable addedRows =
+         comparer == null ? new SortedTable(rows, sortCols) :
+            new SortedTable(rows, comparer);
+      int addedRowsIndex = 0;
+      SortRow newRow = addedRows.getRowByIndex(addedRowsIndex);
+      for (int i = 0; i < this.rows.Count; i++) {
+         if (newRow.CompareTo(this.rows[i]) <= 0) {
+            this.rows.Insert(i, newRow);
+            rowIndex[(int)newRow["id"]] = newRow;
+            if (++addedRowsIndex == addedRows.Count) {
+               return;
+            }
+            newRow = addedRows.getRowByIndex(addedRowsIndex);
+         }
+      }
+      if (addedRowsIndex < addedRows.Count) {
+         for (int i = addedRowsIndex; i < addedRows.Count; i++) {
+            newRow = addedRows.getRowByIndex(i);
+            this.rows.Add(newRow);
+            rowIndex[(int)newRow["id"]] = newRow;
+         }
+      }
+   }
+
+   public void deleteRows(IBlueRowCollection deletedRows) {
+      foreach (IBlueRow deletedRow in deletedRows) {
+         var row = rowIndex[(int)deletedRow["id"]!] as SortRow
+            ?? throw new InvalidOperationException("Index did not return IBlueRow");
+         rows.Remove(row);
+         rowIndex.Remove((int)row["id"]!);
+      }
+   }
+
+   public SortRow getRowByIndex(int index) =>
+      rows[index]!;
+
+   public bool containsID(int id) =>
+      rowIndex[id] is not null;
+
+   public IEnumerator GetEnumerator() =>
+      rows.GetEnumerator();
+
+   public void CopyTo(Array array, int index) {
+      for (int i = 0; i < Count; i++) {
+         array.SetValue(rows[i], index + i);
+      }
+   }
+
+   [MemberNotNull(nameof(schema))]
+   void init(IBlueRowCollection rows) {
+      schema = rows.schema;
+      foreach (IBlueRow row in rows) {
+         SortRow newRow = comparer is null ?
+            new(row, sortCols) : new(row, comparer);
+         this.rows.Add(newRow);
+         rowIndex[(int)row["id"]!] = newRow;
+      }
+      this.rows.Sort();
+   }
+}

src/DataStreamSuite/DataStream/Primitives/Time/DateStandardizationStream.cs

@@ -0,0 +1,143 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+
+
+namespace BCG
+{
+   /// <summary>
+   /// If one adds annother value to this enum, be sure to update _date_conversion_to_type_map below as well
+   /// </summary>
+   public enum DateConversion
+   {
+      ConvertDoubleToDateTime = 0,
+      ChopTime,
+      UTCToCurrent,
+      ConvertStringToDateTime,
+      ConvertDateTimeToMilliseconds,
+      SecondsOfDay
+   }
+
+   [DataStreamUserRespresentation("dateStandardize")]
+   public class DateStandardizationStream : ViewStream, IStreamMapper
+   {
+      private IBlueTableSchema mySchema;
+      private DateConversion myConversion;
+      private string myConversionColName;
+      private readonly Dictionary<DateConversion, Type> _date_conversion_to_type_map = new Dictionary<DateConversion, Type>()
+      {
+         {DateConversion.ConvertDoubleToDateTime      , typeof(DateTime)},
+         {DateConversion.ChopTime                     , typeof(DateTime)},
+         {DateConversion.UTCToCurrent                 , typeof(DateTime)},
+         {DateConversion.ConvertStringToDateTime      , typeof(DateTime)},
+         {DateConversion.ConvertDateTimeToMilliseconds, typeof(Double)},
+         {DateConversion.SecondsOfDay                 , typeof(Double)}
+      };
+
+
+      private static DateConversion _parse(string s)
+      {
+         DateConversion rv = DateConversion.ChopTime;
+         Enum.TryParse<DateConversion>(s, false, out rv);
+         return rv;
+      }
+      /// <summary>
+      /// for DSQA
+      /// </summary>
+      public DateStandardizationStream(ViewStream vs, string colName, string conversion)
+         : this(vs, colName, _parse(conversion))
+      { }
+
+      public DateStandardizationStream(ViewStream vs, string colName, DateConversion conversion)
+      {
+         myConversionColName = colName;
+         myConversion = conversion;
+         mySetRealSource(new MapStream(vs, this));
+      }
+
+      #region IStreamMapper Members
+
+      public IBlueTableSchema getOutputSchema(IBlueTableSchema inputSchema)
+      {
+         if (mySchema == null)
+         {
+            List<ColumnInfo> cis = new List<ColumnInfo>();
+            foreach (ColumnInfo c in inputSchema.columnInfo)
+            {
+               if (c.colName == myConversionColName)
+               {
+                  Type convType;
+                  if (!_date_conversion_to_type_map.TryGetValue(myConversion, out convType))
+                  {
+                     //BCG.Utilities.BlueEventLog.logEvent("Please update the _date_conversion_to_type_map in DateStandardizationStream.cs.", BCG.Utilities.BlueEventLevel.Error);
+                     convType = typeof(DateTime);
+                  }
+                  cis.Add(new ColumnInfo(c.colName, c.colNo, convType));
+               }
+               else
+                  cis.Add(new ColumnInfo(c.colName, c.colNo, c.colType));
+            }
+            mySchema = new BlueTableSchema(inputSchema.tableName, cis.ToArray());
+         }
+         return mySchema;
+      }
+
+      #endregion
+
+      #region IDynamicStreamMapper Members
+
+      public IBlueRow map(IBlueRow row)
+      {
+         return BlueDataUtility.getNewReplacedRow(row, mapDateTime(row[myConversionColName], myConversion), myConversionColName);
+      }
+
+      #endregion
+
+      public static object mapDateTime(object objIn, DateConversion conv)
+      {
+         if (objIn == DBNull.Value || objIn == null)
+         {
+            return DBNull.Value;
+         }
+         else
+         {
+            if (conv == DateConversion.ChopTime)
+            {
+               DateTime dtIn = (DateTime)objIn;
+               return dtIn.Date;
+            }
+            else if (conv == DateConversion.ConvertDoubleToDateTime)
+            {
+               double dtIn = (double)objIn;
+               return DateTime.FromOADate(dtIn);
+            }
+            else if (conv == DateConversion.UTCToCurrent)
+            {
+               DateTime dtIn = (DateTime)objIn;
+               return dtIn.ToLocalTime();
+            }
+            else if (conv == DateConversion.ConvertStringToDateTime)
+            {
+               return DateTime.Parse((string)objIn);
+            }
+            else if (conv == DateConversion.ConvertDateTimeToMilliseconds)
+            {
+               DateTime dtIn = (DateTime)objIn;
+               return dtIn.TimeOfDay.TotalMilliseconds;
+            }
+            else if (conv == DateConversion.SecondsOfDay)
+            {
+               DateTime dtIn = (DateTime)objIn;
+               DateTime start_of_day = dtIn.Date;
+               TimeSpan day_period = dtIn - start_of_day;
+               return day_period.TotalSeconds;
+            }
+            else
+            {
+               bts.Log.Gen.info("incorrect type");
+               return null;
+            }
+         }
+      }
+   }
+}

src/DataStreamSuite/DataStream/Primitives/Time/TimeBucketStream

@@ -0,0 +1,51 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.Collections;
+
+namespace BCG
+{
+   [DataStreamUserRepresentation("timeBucket")]
+   public class TimeBucketStream : ViewStream, IStreamMapper
+   {
+      private ViewStream _src;
+      private readonly string _time_stamp_col;
+      private IBlueTableSchema _schema;
+      private uint _bucket_size_seconds;
+
+      public TimeBucketStream(ViewStream input, string time_stamp_col, uint bucket_size_seconds)
+      {
+         _time_stamp_col = time_stamp_col;
+         _bucket_size_seconds = bucket_size_seconds;
+      }
+
+      #region IStreamMapper Members
+      public IBlueTableSchema getOutputSchema(IBlueTableSchema input_schema)
+      {
+         IBlueTableSchema rv = input_schema;
+         //rv = BlueDataUtility.remove_columns(rv, _time_stamp_col);
+         rv = BlueDataUtility.add_column(rv, "bucket_number", typeof(int));
+         return rv;
+
+      }
+
+      #endregion
+
+      #region IDynamicStreamMapper Members
+
+      public IBlueRow map(IBlueRow row)
+      {
+         DateTime ts = row.get<DateTime>(_time_stamp_col);
+         TimeSpan time_of_day = (ts - ts.Date)
+         int seconds = Convert.ToInt32(time_of_day.TotalSeconds);
+         int buckets = seconds / _bucket_size_seconds;
+         int bucket_number = Math.Floor(buckets);
+         MutableBlueRow rv = new MutableBlueRow(row, getOutputSchema(row.schema))
+         rv.setValue("bucket_number", bucket_number);
+      }
+
+      #endregion
+   }
+}

src/DataStreamSuite/DataStream/Primitives/Time/TimeUnitStream.cs

@@ -1,10 +1,9 @@
 using System;
+
 using BCG.Utilities.General;
 
-namespace BCG
-{
-	public abstract class TimeUnitStream : ViewStream, IWorker
-	{
+namespace BCG {
+   public abstract class TimeUnitStream : ViewStream, IWorker {
       protected TimeSpan myOffset;
       protected DateTime myConstructionTime;
       protected int mySizeOfStream;
@@ -13,87 +12,80 @@ namespace BCG
       protected ViewStreamDatabase myDb;
       protected int myId = 0;
 
-      public TimeUnitStream (DateTime zeroTime, TimeSpan offSet, int sizeOfStream, ViewStreamDatabase db)
-		{
+      public TimeUnitStream(DateTime zeroTime, TimeSpan offSet, int sizeOfStream, ViewStreamDatabase db) {
          myConstructionTime = DateTime.Now;
          myZeroTime = zeroTime;
          myOffset = offSet;
          mySizeOfStream = sizeOfStream;
          myDb = db;
-         myCollection = new CircularRowCollection (
-            new BlueTableSchema ("Time",
-            new ColumnInfo ("id", 0, typeof(Int32)), new ColumnInfo ("time", 1, typeof(DateTime))), 
+         myCollection = new CircularRowCollection(
+            new BlueTableSchema("Time",
+            new ColumnInfo("id", 0, typeof(Int32)), new ColumnInfo("time", 1, typeof(DateTime))),
             mySizeOfStream);
-		}
+      }
 
       #region ViewStream overriden methods
 
-      protected override void myOnFirstSubscriber()
-      {
-         myDb.addWorker (this);
-         myInit ();
+      protected override void myOnFirstSubscriber() {
+         myDb.addWorker(this);
+         myInit();
       }
 
-      protected override void myOnLastSubscriber()
-      {
-         myDb.removeWorker (this);
+      protected override void myOnLastSubscriber() {
+         myDb.removeWorker(this);
       }
 
       #endregion
 
-      protected virtual void myInit ()
-      {
+      protected virtual void myInit() {
          int periods = (int)
-            (DateTime.Now - myConstructionTime).TotalMilliseconds / (int) myOffset.TotalMilliseconds;
-            
+            (DateTime.Now - myConstructionTime).TotalMilliseconds / (int)myOffset.TotalMilliseconds;
 
-         DateTime dt = myGetLatestRow() == null ? myRoundTime(myZeroTime) : 
-            myRoundTime (myZeroTime + new TimeSpan(myOffset.Ticks * periods));
+
+         DateTime dt = myGetLatestRow() == null ? myRoundTime(myZeroTime) :
+            myRoundTime(myZeroTime + new TimeSpan(myOffset.Ticks * periods));
 
 
          if (myGetLatestRow() == null ||
-            !myGetLatestRow()["time"].Equals(dt))
-         {
-            IBlueRow ar = new BlueRow (myCollection.schema,
+            !myGetLatestRow()["time"].Equals(dt)) {
+            IBlueRow ar = new BlueRow(myCollection.schema,
                myId++, dt);
-            IBlueRow dr = myCollection.addRowWithReturn (ar);
-            myFireEvent (new DataPacket (myCollection,
-               myConvertToCollection (ar),
-               myConvertToCollection (dr)));
+            IBlueRow dr = myCollection.addRowWithReturn(ar);
+            if (n_updates <= 3000)
+               myFireEvent(new DataPacket(myCollection,
+                  myConvertToCollection(ar),
+                  myConvertToCollection(dr)));
          }
       }
 
       #region IWorker methods
 
-      public void doWork ()
-      {
-         myInit ();
+      public void doWork() {
+         myInit();
       }
 
       #endregion
 
-      protected abstract DateTime myRoundTime (DateTime dt);
-         
+      protected abstract DateTime myRoundTime(DateTime dt);
+
 
       #region Private Helper methods
 
-      private IBlueRow myGetLatestRow ()
-      {
+      private IBlueRow myGetLatestRow() {
          return myCollection.Count == 0 ?
             null :
-            BlueDataUtility.extractRow (myCollection, myCollection.Count - 1);
+            BlueDataUtility.extractRow(myCollection, myCollection.Count - 1);
       }
 
-      private IBlueRowCollection myConvertToCollection (IBlueRow r)
-      {
-         BlueTable retVal = new BlueTable (myCollection.schema);
+      private IBlueRowCollection myConvertToCollection(IBlueRow r) {
+         BlueTable retVal = new BlueTable(myCollection.schema);
          if (r != null)
-            retVal.addRow (r);
+            retVal.addRow(r);
          return retVal;
       }
 
       #endregion
 
-	}
+   }
 
 }

src/DataStreamSuite/DataStream/Primitives/Top/TopStream.cs

@@ -1,49 +1,43 @@
-// using System;
+using System;
 
-// namespace BCG
-// {
-//    public class TopStream : MethodDrivenStream
-//    {
-//       private int myTopCount;
+namespace BCG {
+    public class TopStream : MethodDrivenStream {
+        private int myTopCount;
 
-//       public TopStream (ViewStream stream, int topCount) : base (stream)  {myTopCount = topCount;}
+        public TopStream(ViewStream stream, int topCount) : base(stream) { myTopCount = topCount; }
 
-//       public TopStream (ViewStream stream, 
-//          int topCount, 
-//          string sortExpression) 
-//          :
-//          this (sortExpression == null? 
-//          stream :
-//          new SortStream (stream, sortExpression), topCount)
-//       {}
+        public TopStream(ViewStream stream,
+           int topCount,
+           string sortExpression)
+           :
+           this(sortExpression == null ?
+           stream :
+           new SortStream(stream, sortExpression), topCount) { }
 
-//       protected override void myOnTableClear () 
-//       {
-//          myLastFiredPacket.deletedRows = myLastFiredPacket.newRows;
-//          myLastFiredPacket.newRows = new OrderedBlueTable (myLastFiredPacket.deletedRows.schema);
-//          myLastFiredPacket.addedRows = new OrderedBlueTable (myLastFiredPacket.deletedRows.schema);
-//       }
+        protected override void myOnTableClear() {
+            myLastFiredPacket.deletedRows = myLastFiredPacket.newRows;
+            myLastFiredPacket.newRows = new OrderedBlueTable(myLastFiredPacket.deletedRows.schema);
+            myLastFiredPacket.addedRows = new OrderedBlueTable(myLastFiredPacket.deletedRows.schema);
+        }
 
-//       protected override void myHandleFirstCall () 
-//       {
-//          myLastFiredPacket = new DataPacket ();
-//          myLastFiredPacket.newRows = new OrderedBlueTable (myLastArrivedPacket.newRows, myTopCount);
-//          myLastFiredPacket.addedRows = new OrderedBlueTable(myLastFiredPacket.newRows);
-//          myLastFiredPacket.deletedRows = new OrderedBlueTable (myLastFiredPacket.newRows.schema);
-//       }
+        protected override void myHandleFirstCall() {
+            myLastFiredPacket = new DataPacket();
+            myLastFiredPacket.newRows = new OrderedBlueTable(myLastArrivedPacket.newRows, myTopCount);
+            myLastFiredPacket.addedRows = new OrderedBlueTable(myLastFiredPacket.newRows);
+            myLastFiredPacket.deletedRows = new OrderedBlueTable(myLastFiredPacket.newRows.schema);
+        }
 
-//       protected override void myHandleIncrementalAdd ()     {}
+        protected override void myHandleIncrementalAdd() { }
 
-//       protected override void myHandleIncrementalDelete()   
-//       {
-//          IBlueRowCollection oldRows = myLastFiredPacket.newRows;
-//          myLastFiredPacket.newRows = new OrderedBlueTable (myLastArrivedPacket.newRows, myTopCount);
-//          BlueDataUtility.computeDifferences (myLastFiredPacket.newRows,
-//             oldRows,
-//             myLastFiredPacket.schema.columnNames,
-//             out myLastFiredPacket.deletedRows,
-//             out myLastFiredPacket.addedRows);
-//          myFireSwitch = myLastFiredPacket.addedRows.Count + myLastFiredPacket.deletedRows.Count == 0 ? false : true;
-//       }
-//    }
-// }
+        protected override void myHandleIncrementalDelete() {
+            IBlueRowCollection oldRows = myLastFiredPacket.newRows;
+            myLastFiredPacket.newRows = new OrderedBlueTable(myLastArrivedPacket.newRows, myTopCount);
+            BlueDataUtility.computeDifferences(myLastFiredPacket.newRows,
+               oldRows,
+               myLastFiredPacket.schema.columnNames,
+               out myLastFiredPacket.deletedRows,
+               out myLastFiredPacket.addedRows);
+            myFireSwitch = myLastFiredPacket.addedRows.Count + myLastFiredPacket.deletedRows.Count == 0 ? false : true;
+        }
+    }
+}

src/DataStreamSuite/DataStream/Publish/PubTableBroker.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Collections;
 using System.Collections.Generic;
+using System.Linq.Expressions;
+using System.Xml.Serialization;
 
 using BCG.Utilities;
 
@@ -53,7 +55,12 @@ namespace BCG {
       }
 
       public virtual void createTable(IBlueRowCollection newTable) {
-         bts.Log.Gen.info($"PubTableBroker.createTable table: {newTable.schema.tableName}");
+         string log_msg = $"PubTableBroker.createTable table: {newTable.schema.tableName}\n";
+         foreach (IBlueRow r in newTable) {
+            log_msg += $"id: {r["id"]}";
+         }
+         bts.Log.Gen.info(log_msg);
+         _check_schema_consistency(newTable.schema);
          myCheckTransaction();
          IPubTablePublisher table_publisher = null;
          var name_key = newTable.schema.tableName.ToLower();
@@ -71,6 +78,9 @@ namespace BCG {
       /// </summary>
       /// <param name="r"></param>
       public virtual void addRow(IBlueRow r) {
+         string log_msg = $"PubTableBroker.addRow table: {r.schema.tableName} id: {r["id"]}";
+         bts.Log.Gen.info(log_msg);
+         _check_schema_consistency(r.schema);
          myCheckTransaction();
          IPubTablePublisher table_publisher = null;
          var name_key = r.schema.tableName.ToLower();
@@ -86,6 +96,9 @@ namespace BCG {
       /// </summary>
       /// <param name="r"></param>
       public virtual void deleteRow(IBlueRow r) {
+         string log_msg = $"PubTableBroker.deleteRow table: {r.schema.tableName} id: {r["id"]}";
+         bts.Log.Gen.info(log_msg);
+         _check_schema_consistency(r.schema);
          myCheckTransaction();
          IPubTablePublisher table_publisher = null;
          var name_key = r.schema.tableName.ToLower();
@@ -101,6 +114,9 @@ namespace BCG {
       /// </summary>
       /// <param name="r"></param>
       public virtual void changeRow(IBlueRow r) {
+         string log_msg = $"PubTableBroker.changeRow table: {r.schema.tableName} id: {r["id"]}";
+         bts.Log.Gen.info(log_msg);
+         _check_schema_consistency(r.schema);
          myCheckTransaction();
          IPubTablePublisher table_publisher = null;
          var name_key = r.schema.tableName.ToLower();
@@ -118,7 +134,16 @@ namespace BCG {
       public virtual void makeBatchChanges(IBlueRowCollection newRows,
                                              IBlueRowCollection deletedRows,
                                              IBlueRowCollection addedRows) {
-         myCheckTransaction();
+         string log_msg = $"PubTableBroker.makeBatchChanges {deletedRows.Count} {addedRows.Count} table: {newRows.schema.tableName} deleted_rows: ";
+         foreach (IBlueRow r in deletedRows)
+            log_msg += $"id: {r["id"]} ";
+         log_msg += "addedRows: ";
+         foreach (IBlueRow r in addedRows)
+            log_msg += $"id: {r["id"]}";
+         bts.Log.Gen.info(log_msg);
+         _check_schema_consistency(newRows.schema);
+         _check_schema_consistency(deletedRows.schema);
+         _check_schema_consistency(addedRows.schema);
          IPubTablePublisher table_publisher = null;
          var name_key = newRows.schema.tableName.ToLower();
          if (!_publisher_map.TryGetValue(name_key, out table_publisher))
@@ -144,8 +169,16 @@ namespace BCG {
       }
 
       protected virtual IPubTablePublisher _create_pubtable_publisher(string tag) {
+         bts.Log.Gen.info($"PubTableBroker._create_pubtable_publisher tag: {tag}");
          return new PubTablePublisher(tag, _publisher_core);
       }
 
+      private void _check_schema_consistency(IBlueTableSchema schema_arg) {
+         IBlueTableSchema schema;
+         if (_schema_map.TryGetValue(schema_arg.tableName, out schema)) {
+            bts.Log.assert(BlueDataUtility.compareSchemas(schema, schema_arg));
+         }
+      }
+
    }
 }

src/DataStreamSuite/DataStream/Publish/ViewPublisher.cs

@@ -14,7 +14,7 @@ namespace BCG {
       /// is not uniquely chosen)
       public ViewPublisher(string name, PubTableBroker br, ViewStream vs) {
          myName = name;
-         myView = vs;//String.IsNullOrEmpty(name) ? vs : new ProjectStream(vs, "!", myName);
+         myView = String.IsNullOrEmpty(name) ? vs : new ChangeTableNameStream(vs, name);
          myBroker = br;
          myFirstTime = true;
          myView.onChange += new DataStream.ChangeDelegate(myChangeHandler);

src/DataStreamSuite/DataStreamCore/BlueData/BlueTable.cs

@@ -5,14 +5,12 @@ using System.Data;
 //using BCG.Utilities;
 using System.Linq;
 
-namespace BCG
-{
+namespace BCG {
    /// <summary>
    /// Anologue of the dotNet DataTable.
    /// </summary>
    [Serializable]
-   public class BlueTable : IBlueRowCollection
-   {
+   public class BlueTable : IBlueRowCollection {
       /// <summary>
       /// Hashtable indexed on "id" to speed up removes
       /// </summary>
@@ -29,22 +27,19 @@ namespace BCG
       /// all the data over
       /// </summary>
       /// <param name="table"></param>
-      public BlueTable(DataTable table)
-      {
+      public BlueTable(DataTable table) {
          ColumnInfo[] cis = new ColumnInfo[table.Columns.Count];
          int i = 0;
          foreach (DataColumn col in table.Columns)
             cis[i] = new ColumnInfo(col.ColumnName, i++, col.DataType);
          mySchema = new BlueTableSchema(cis, table.TableName);
-         foreach (DataRow row in table.Rows)
-         {
+         foreach (DataRow row in table.Rows) {
             IBlueRow newRow = new BlueRow(mySchema, row.ItemArray);
             myIdIndex[newRow["id"]] = newRow;
          }
       }
 
-      public BlueTable(IBlueRowCollection table)
-      {
+      public BlueTable(IBlueRowCollection table) {
          mySchema = table.schema;
          foreach (IBlueRow row in table)
             addRow(row);
@@ -52,12 +47,10 @@ namespace BCG
 
       public BlueTable(string tableName,
           IEnumerable objects,
-          params CMap[] columnMappers)
-      {
+          params CMap[] columnMappers) {
          // extract schema from mappers
          ColumnInfo[] cols = new ColumnInfo[columnMappers.Length];
-         for (int i = 0; i < columnMappers.Length; i++)
-         {
+         for (int i = 0; i < columnMappers.Length; i++) {
             cols[i] = new ColumnInfo(
                 columnMappers[i].getColumnName(), i,
                 columnMappers[i].getColumnType());
@@ -66,8 +59,7 @@ namespace BCG
 
          // load rows
          int rowNumber = 0;
-         foreach (object rowObject in objects)
-         {
+         foreach (object rowObject in objects) {
             object[] values = new object[columnMappers.Length];
             for (int cn = 0; cn < columnMappers.Length; cn++)
                values[cn] = columnMappers[cn].getColumnValue(rowNumber, rowObject);
@@ -87,10 +79,8 @@ namespace BCG
       /// <summary>
       /// Returns the row by the index, interface property
       /// </summary>
-      public virtual IBlueRow this[int id]
-      {
-         get
-         {
+      public virtual IBlueRow this[int id] {
+         get {
             object row = myIdIndex[id];
             if (row == null)
                throw new BlueDataException("ID " + id.ToString() + " does not exist in table " + mySchema.tableName);
@@ -105,8 +95,7 @@ namespace BCG
 
       public virtual bool containsID(int id) { return myIdIndex[id] != null; }
 
-      public virtual bool tryGetValue(int id, out IBlueRow row)
-      {
+      public virtual bool tryGetValue(int id, out IBlueRow row) {
          row = (IBlueRow)myIdIndex[id];
          return (row != null);
       }
@@ -114,8 +103,7 @@ namespace BCG
       #endregion
 
       #region BlueTable members
-      public virtual void clear()
-      {
+      public virtual void clear() {
          myIdIndex.Clear();
       }
 
@@ -123,8 +111,7 @@ namespace BCG
       /// If a row with the same id exists, it replaces it
       /// </summary>
       /// <param name="r"></param>
-      public virtual void forceAddRow(IBlueRow r)
-      {
+      public virtual void forceAddRow(IBlueRow r) {
          myIdIndex[r["id"]] = r;
       }
 
@@ -132,43 +119,41 @@ namespace BCG
       /// Adds a new row to the table. 
       /// </summary>
       /// <param name="row"></param>
-      public virtual void addRow(IBlueRow row)
-      {
+      public virtual void addRow(IBlueRow row) {
          object id = row["id"];
 
          if (id == null || id == DBNull.Value)
             throw new BlueDataException("The ID of the row being added is null/DNBull");
-         try
-         {
+         try {
             myIdIndex.Add(id, row);
-         }
-         catch (ArgumentException)
-         {
-            throw new BlueDataException($"ID {id} already exists in the table: {mySchema.tableName} , duplication of field ID not allowed");
+         } catch (ArgumentException) {
+            throw new BlueDataException($"ID: {id} already exists in the table: {mySchema.tableName}");
          }
 
       }
 
-      public virtual void addRow(DataRow row)
-      {
+      public virtual void addRow(DataRow row) {
          object val = row["id"];
 
          if (val == null || val == DBNull.Value)
             throw new BlueDataException("The ID of the row being added is null/DNBull");
-         if (myIdIndex[val] != null)
-            throw new BlueDataException("ID already exists in the table, duplication of field ID not allowed");
+         if (myIdIndex[val] != null) {
+            string err_msg = $"ID: {val} already exists in the table: {mySchema.tableName} duplication of field ID not allowed";
+            // temp TODOds remove it
+            bts.Log.assert(false, err_msg);
+            throw new BlueDataException(err_msg);
+
+         }
          IBlueRow newRow = new BlueRow(mySchema, row);
          myIdIndex[val] = newRow;
       }
 
-      public virtual void addRows(IBlueRowCollection rows)
-      {
+      public virtual void addRows(IBlueRowCollection rows) {
          foreach (IBlueRow nr in rows)
             addRow(nr);
       }
 
-      public virtual void addRows(IEnumerable rows)
-      {
+      public virtual void addRows(IEnumerable rows) {
          foreach (IBlueRow nr in rows)
             addRow(nr);
       }
@@ -185,37 +170,32 @@ namespace BCG
       /// Removes a row specified by the id. The index helps in making this operation O(1)
       /// </summary>
       /// <param name="id"></param>
-      public virtual bool deleteRow(int id)
-      {
+      public virtual bool deleteRow(int id) {
          if (myIdIndex[id] == null)
             return false;
          myIdIndex.Remove(id);
          return true;
       }
 
-      public virtual bool deleteRows(IBlueRowCollection rows)
-      {
+      public virtual bool deleteRows(IBlueRowCollection rows) {
          bool retVal = true;
          foreach (IBlueRow r in rows)
             retVal &= deleteRow(r);
          return retVal;
       }
 
-      public virtual bool deleteRows(IEnumerable rows)
-      {
+      public virtual bool deleteRows(IEnumerable rows) {
          bool retVal = true;
          foreach (IBlueRow r in rows)
             retVal &= deleteRow(r);
          return retVal;
       }
 
-      public virtual void changeRow(IBlueRow r)
-      {
+      public virtual void changeRow(IBlueRow r) {
          myIdIndex[r["id"]] = r;
       }
 
-      public virtual void changeRows(IBlueRowCollection rows)
-      {
+      public virtual void changeRows(IBlueRowCollection rows) {
          foreach (IBlueRow r in rows)
             changeRow(r);
       }

src/DataStreamSuite/DataStreamCore/BlueData/CircularRowCollection.cs

@@ -11,17 +11,17 @@ namespace BCG
    public class CircularRowCollection : OrderedBlueTable
    {
       private int myBufferSize;
-      public CircularRowCollection (IBlueTableSchema schema, int bufferSize)
-         : base (schema)
-      {		
-         myBufferSize = bufferSize ;
+      public CircularRowCollection(IBlueTableSchema schema, int bufferSize)
+         : base(schema)
+      {
+         myBufferSize = bufferSize;
       }
 
-      public CircularRowCollection (IBlueRowCollection rows, int bufferSize)
-         : this (rows.schema, bufferSize)
+      public CircularRowCollection(IBlueTableSchema schema, IEnumerable<IBlueRow> rows, int bufferSize)
+         : this(schema, bufferSize)
       {
          foreach (IBlueRow r in rows)
-            addRow (r);
+            addRow(r);
       }
 
       public int bufferSize
@@ -39,30 +39,30 @@ namespace BCG
       /// </summary>
       /// <param name="r"></param>
       /// <returns></returns>
-      public IBlueRow addRowWithReturn (IBlueRow r)
+      public IBlueRow addRowWithReturn(IBlueRow r)
       {
-         base.addRow (r);
+         base.addRow(r);
          if (myOrderedRows.Count > myBufferSize)
          {
-            IBlueRow retVal = myOrderedRows [0] as IBlueRow;
-            deleteRow (retVal);
+            IBlueRow retVal = myOrderedRows[0] as IBlueRow;
+            deleteRow(retVal);
             return retVal;
          }
          return null;
       }
 
-      public override void addRow (IBlueRow row)
+      public override void addRow(IBlueRow row)
       {
-         base.addRow (row);
+         base.addRow(row);
          if (myOrderedRows.Count > myBufferSize)
-            deleteRow (myOrderedRows [0] as IBlueRow);
+            deleteRow(myOrderedRows[0] as IBlueRow);
       }
 
-      public override void addRow (DataRow row)
+      public override void addRow(DataRow row)
       {
-         base.addRow (row);
+         base.addRow(row);
          if (myOrderedRows.Count > myBufferSize)
-            deleteRow (myOrderedRows [0] as IBlueRow);
+            deleteRow(myOrderedRows[0] as IBlueRow);
       }
 
       public void add_rows(IEnumerable<IBlueRow> rows_to_add, out IBlueRowCollection added_rows, out IBlueRowCollection deleted_rows)

src/DataStreamSuite/DataStreamCore/BlueData/MetaDataField.cs

@@ -3,8 +3,7 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Text;
 
-namespace BCG
-{
+namespace BCG {
    /*
       These fields are first going to be used by  BlueRay to help it determine what differnet tags mean, but eventually
     * the goal is that they will be used for all services in this system. 
@@ -12,11 +11,12 @@ namespace BCG
     * not all metadata fields are present in all metadata; it depends upon the class. For example, a bluepages service
     * probably won't have a 'symbol' or 'exchange' field populated, but it'll probably have the 'type' of service populated
     */
-   public enum MetaDataField {   Protocol,  //is this a bluepages service, a pubsub tag, a blueray tag, a 29 west thing, or what
-                                 Type,   //if it's a multicast, is it option, fireprice, whatever. If it's bluepages, is it persistence, pubsub, whatever
-                                 Symbol, 
-                                 Exchange,
-                                 Platform,
-                                 MarketDataType, // BAM (bid, ask, mid), last, etc
-                                 RealName }; //does this thing have a better name we could call it
+   public enum MetaDataField {
+      Protocol,       // is this a bluepages service, a pubsub tag, a blueray tag, a 29 west thing, or what
+      Type,           // if it's a multicast, is it option, fireprice, whatever. If it's bluepages, is it persistence, pubsub, whatever
+      Symbol,
+      Exchange,
+      MarketDataType, // BAM (bid, ask, mid), last, etc
+      RealName
+   }; //does this thing have a better name we could call it
 }

src/DataStreamSuite/DataStreamCore/DataPacket.cs

@@ -1,316 +1,316 @@
-// using System;
-// using System.Collections;
-// using System.Data;
-// using BCG.Utilities.General;
+using System;
+using System.Collections;
+using System.Data;
+using BCG.Utilities.General;
 
-// namespace BCG
-// {
-// 	[Serializable]
-//    public class DataPacket : ICloneable, IDataPacket
-//    {      
-//       public class BlueRowIdComparator
-//       {
-//          private string[] myIdColumns = new string[]{"id"};
+namespace BCG
+{
+	[Serializable]
+   public class DataPacket : ICloneable, IDataPacket
+   {      
+      public class BlueRowIdComparator
+      {
+         private string[] myIdColumns = new string[]{"id"};
 
-//          public BlueRowIdComparator(string[] idCols)
-//          {
-//             if ( idCols.Length != 0 ) 
-//             {
-//                myIdColumns = idCols;
-//             }
-//          }
+         public BlueRowIdComparator(string[] idCols)
+         {
+            if ( idCols.Length != 0 ) 
+            {
+               myIdColumns = idCols;
+            }
+         }
+                    
+         public  bool blueRowIdEqualEvaluator(object a, object b)
+         {
+            if ( a == null || b == null )
+            {
+               return false;
+            }
 
-//          public  bool blueRowIdEqualEvaluator(object a, object b)
-//          {
-//             if ( a == null || b == null )
-//             {
-//                return false;
-//             }
+            if ( !(a is IBlueRow) || !(b is IBlueRow) )
+            {
+               return false;
+            }
 
-//             if ( !(a is IBlueRow) || !(b is IBlueRow) )
-//             {
-//                return false;
-//             }
+            IBlueRow lhs = (IBlueRow)a;
+            IBlueRow rhs = (IBlueRow)b;
+                    
+            bool result = true;
+            foreach(string idColumn in myIdColumns)
+            {
+               result = result && lhs[idColumn].Equals(rhs[idColumn]);
+               if ( !result )
+                  break;
+            }
 
-//             IBlueRow lhs = (IBlueRow)a;
-//             IBlueRow rhs = (IBlueRow)b;
+            return result;            
+         }
+      }
 
-//             bool result = true;
-//             foreach(string idColumn in myIdColumns)
-//             {
-//                result = result && lhs[idColumn].Equals(rhs[idColumn]);
-//                if ( !result )
-//                   break;
-//             }
+      public IBlueRowCollection newRows, addedRows, deletedRows;
+      public DataPacket () {}
+      public DataPacket (IBlueRowCollection newRows, IBlueRowCollection addedRows, IBlueRowCollection deletedRows)
+      {
+         this.newRows = newRows;
+         this.addedRows = addedRows;
+         this.deletedRows = deletedRows;
+      }
 
-//             return result;            
-//          }
-//       }
+      public void get_new_added_deleted(out ICollection new_rows, out ICollection added_rows, out ICollection deleted_rows)
+      {
+         new_rows = newRows;
+         added_rows = addedRows;
+         deleted_rows = deletedRows;
+      }
 
-//       public IBlueRowCollection newRows, addedRows, deletedRows;
-//       public DataPacket () {}
-//       public DataPacket (IBlueRowCollection newRows, IBlueRowCollection addedRows, IBlueRowCollection deletedRows)
-//       {
-//          this.newRows = newRows;
-//          this.addedRows = addedRows;
-//          this.deletedRows = deletedRows;
-//       }
+      public IBlueRowCollection getTrulyAddedRows(params string[] idColumns)
+      {                 
+         BlueTable truly = new BlueTable(addedRows.schema);
+         BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
 
-//       public void get_new_added_deleted(out ICollection new_rows, out ICollection added_rows, out ICollection deleted_rows)
-//       {
-//          new_rows = newRows;
-//          added_rows = addedRows;
-//          deleted_rows = deletedRows;
-//       }
+         CollectionHelpers.EqualDelegate ed = 
+            new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
 
-//       public IBlueRowCollection getTrulyAddedRows(params string[] idColumns)
-//       {                 
-//          BlueTable truly = new BlueTable(addedRows.schema);
-//          BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
+         ICollection ta = CollectionHelpers.difference(addedRows, deletedRows, ed);
+           
+         foreach(IBlueRow r in ta)
+         {
+            truly.addRow(r);
+         }
+           
+         return truly;
+                
+      }
 
-//          CollectionHelpers.EqualDelegate ed = 
-//             new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
+      public virtual IBlueRowCollection getTrulyAddedRows ()
+      {
+         BlueTable retVal = new BlueTable (schema);
+         foreach (IBlueRow r in addedRows)
+            if (!deletedRows.containsID ((int)r["id"]))
+               retVal.addRow (r);
+         return retVal;
+      }
 
-//          ICollection ta = CollectionHelpers.difference(addedRows, deletedRows, ed);
+      public virtual IBlueRowCollection getTrulyDeletedRows ()
+      {
+         BlueTable retVal = new BlueTable (schema);
+         foreach (IBlueRow r in deletedRows)
+            if (!addedRows.containsID ((int)r["id"]))
+               retVal.addRow (r);
+         return retVal;
+      }
 
-//          foreach(IBlueRow r in ta)
-//          {
-//             truly.addRow(r);
-//          }
+      public virtual IBlueRowCollection getTrulyChangedRows ()
+      {
+         BlueTable retVal = new BlueTable (schema);
+         foreach (IBlueRow r in addedRows)
+            if (deletedRows.containsID ((int)r["id"]))
+               retVal.addRow (r);
+         return retVal;
+      }
 
-//          return truly;
+      
+      public IBlueRowCollection getTrulyDeletedRows(params string[] idColumns)
+      {        
+         BlueTable truly = new BlueTable(deletedRows.schema);
+         BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
 
-//       }
+         CollectionHelpers.EqualDelegate ed = 
+            new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
 
-//       public virtual IBlueRowCollection getTrulyAddedRows ()
-//       {
-//          BlueTable retVal = new BlueTable (schema);
-//          foreach (IBlueRow r in addedRows)
-//             if (!deletedRows.containsID ((int)r["id"]))
-//                retVal.addRow (r);
-//          return retVal;
-//       }
+         ICollection td = CollectionHelpers.difference(deletedRows, addedRows, ed);
+                      
+         foreach(IBlueRow r in td)
+         {
+            truly.addRow(r);
+         }
 
-//       public virtual IBlueRowCollection getTrulyDeletedRows ()
-//       {
-//          BlueTable retVal = new BlueTable (schema);
-//          foreach (IBlueRow r in deletedRows)
-//             if (!addedRows.containsID ((int)r["id"]))
-//                retVal.addRow (r);
-//          return retVal;
-//       }
+         return truly;      
+      }
+      
+      public IBlueRowCollection getTrulyChangedRows(params string[] idColumns)
+      {
+       
+         BlueTable truly = new BlueTable(addedRows.schema);
+         BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
 
-//       public virtual IBlueRowCollection getTrulyChangedRows ()
-//       {
-//          BlueTable retVal = new BlueTable (schema);
-//          foreach (IBlueRow r in addedRows)
-//             if (deletedRows.containsID ((int)r["id"]))
-//                retVal.addRow (r);
-//          return retVal;
-//       }
+         CollectionHelpers.EqualDelegate ed = 
+            new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
 
+         ICollection ta = CollectionHelpers.difference(addedRows, deletedRows, ed);
+         ICollection tc = CollectionHelpers.difference(addedRows, ta, ed);
+         
+         foreach(IBlueRow r in tc)
+         {
+            truly.addRow(r);
+         }   
+        
+         return truly;      
+      }
+      
+      public IBlueRowCollection getTrulyChangedOldRows(params string[] idColumns)
+      {        
+         BlueTable truly = new BlueTable(deletedRows.schema);
+         BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
 
-//       public IBlueRowCollection getTrulyDeletedRows(params string[] idColumns)
-//       {        
-//          BlueTable truly = new BlueTable(deletedRows.schema);
-//          BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
+         CollectionHelpers.EqualDelegate ed = 
+            new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
 
-//          CollectionHelpers.EqualDelegate ed = 
-//             new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
+         ICollection td = CollectionHelpers.difference(deletedRows, addedRows, ed);
+         ICollection tco = CollectionHelpers.difference(deletedRows, td, ed);
+         
+         foreach(IBlueRow r in tco)
+         {
+            truly.addRow(r);
+         }         
 
-//          ICollection td = CollectionHelpers.difference(deletedRows, addedRows, ed);
+         return truly;         
+      }
+      
+      public TablePacket toTablePacket ()
+      {
+         return new TablePacket (BlueDataUtility.toDataTable (newRows), BlueDataUtility.toDataTable (addedRows),
+                                 BlueDataUtility.toDataTable (deletedRows));
+                                 
+      }
 
-//          foreach(IBlueRow r in td)
-//          {
-//             truly.addRow(r);
-//          }
+      public IBlueTableSchema schema 
+      {
+         get
+         {
+            IBlueTableSchema retVal = newRows.schema != null ? newRows.schema :
+               addedRows.schema != null ? addedRows.schema : deletedRows.schema;
+            return retVal;
+         }
+      }
 
-//          return truly;      
-//       }
+      /*          
+       status  D total  A total  D this   A This   D' total A' Total 
+         x  0  0  0  0  0  0  
+            0  0  0  1     1 this+  
+            0  0  1  0  1this    
+            0  0  1  1  1 this   1 this+  
+         x  0  1  0  0        
+         error 0  1  0  1        
+            0  1  1  0     1 total- 
+            0  1  1  1     1 total-, 1 this +   
+         x  1  0  0  0        
+            1  0  0  1     1 this+  
+         error 1  0  1  0        
+         error 1  0  1  1        
+         x  1  1  0  0        
+         error 1  1  0  1        
+            1  1  1  0     1 total -1  keep the old delete and remove the old add
+            1  1  1  1     1 total-, 1 this +   
+      
+         d' = dthis - (dthis intersect a) + d // keep the old delete
+         a' = a - (dthis intersect a) + athis // keep the new add       
+       * */
+      public static DataPacket combineWithIds(ICollection packets, string[] idColumns)
+      {       
+         if ( packets.Count == 0 )
+         {
+            return new DataPacket(
+               new BlueTable(new DataTable()),
+               new BlueTable(new DataTable()),
+               new BlueTable(new DataTable()));                    
+         }
 
-//       public IBlueRowCollection getTrulyChangedRows(params string[] idColumns)
-//       {
+         DataPacket.BlueRowIdComparator c = new DataPacket.BlueRowIdComparator(idColumns);
+         
+         CollectionHelpers.EqualDelegate ed = 
+            new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
 
-//          BlueTable truly = new BlueTable(addedRows.schema);
-//          BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
+         ArrayList added = new ArrayList();
+         ArrayList deleted = new ArrayList();
+         BlueTable dt = null;
+         BlueTable at = null;
+         IBlueRowCollection nt = null;
 
-//          CollectionHelpers.EqualDelegate ed = 
-//             new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
+         foreach(DataPacket dp in packets)
+         {               
+            ArrayList oldDeleted = deleted;
+            ArrayList oldAdded = added;
 
-//          ICollection ta = CollectionHelpers.difference(addedRows, deletedRows, ed);
-//          ICollection tc = CollectionHelpers.difference(addedRows, ta, ed);
+            added = new ArrayList();
+            deleted = new ArrayList();
+            if ( dt == null )
+            {
+               dt = new BlueTable(dp.schema);
+               at = new BlueTable(dp.schema);
+            }
+            
+            deleted.AddRange(oldDeleted);
+            deleted.AddRange( CollectionHelpers.difference(
+               CollectionHelpers.difference(dp.deletedRows, oldAdded, ed),
+               oldDeleted, ed) );
 
-//          foreach(IBlueRow r in tc)
-//          {
-//             truly.addRow(r);
-//          }   
+            added.AddRange(dp.addedRows);
+            added.AddRange( CollectionHelpers.difference(
+               CollectionHelpers.difference(oldAdded, dp.deletedRows, ed),
+               added, ed) );
+            nt = dp.newRows;
+         }        
+         
+         foreach ( IBlueRow dr in added )
+         {
+            at.addRow(dr);
+         }
 
-//          return truly;      
-//       }
+         foreach ( IBlueRow dr in deleted )
+         {
+            dt.addRow(dr);
+         }
 
-//       public IBlueRowCollection getTrulyChangedOldRows(params string[] idColumns)
-//       {        
-//          BlueTable truly = new BlueTable(deletedRows.schema);
-//          BlueRowIdComparator c = new BlueRowIdComparator(idColumns);
+         return new DataPacket(nt,at,dt);            
+      }
 
-//          CollectionHelpers.EqualDelegate ed = 
-//             new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
+      public DataPacket deepCopy ()
+      {
+         return new DataPacket (new OrderedBlueTable (newRows),
+            new OrderedBlueTable (newRows),
+            new BlueTable (deletedRows));
+      }
 
-//          ICollection td = CollectionHelpers.difference(deletedRows, addedRows, ed);
-//          ICollection tco = CollectionHelpers.difference(deletedRows, td, ed);
+      public virtual DataPacket createImmutable ()
+      {
+         return 
+         new DataPacket(
+               newRows is IImmutableRowCollection ? newRows : new ImmutableBlueTable(newRows),
+               addedRows, 
+               deletedRows);
+      }
+      #region ICloneable Members
 
-//          foreach(IBlueRow r in tco)
-//          {
-//             truly.addRow(r);
-//          }         
+      public object Clone()
+      {
+         return MemberwiseClone();
+      }
 
-//          return truly;         
-//       }
+      #endregion
 
-//       public TablePacket toTablePacket ()
-//       {
-//          return new TablePacket (BlueDataUtility.toDataTable (newRows), BlueDataUtility.toDataTable (addedRows),
-//                                  BlueDataUtility.toDataTable (deletedRows));
+      public string toIncrementalIDString()
+      {
+         System.Text.StringBuilder sb = new System.Text.StringBuilder(schema.tableName);
+         sb.Append ("\ndeleted : ");
+         foreach (IBlueRow r in deletedRows)
+         {
+            sb.Append(r["id"]);
+            sb.Append(',');
+         }
+         sb.Append("\nadded : ");
+         foreach (IBlueRow r in addedRows)
+         {
+            sb.Append(r["id"]);
+            sb.Append(',');
+         }
+         sb.Append("\n");
+         return sb.ToString();
+      }
 
-//       }
-
-//       public IBlueTableSchema schema 
-//       {
-//          get
-//          {
-//             IBlueTableSchema retVal = newRows.schema != null ? newRows.schema :
-//                addedRows.schema != null ? addedRows.schema : deletedRows.schema;
-//             return retVal;
-//          }
-//       }
-
-//       /*          
-//        status  D total  A total  D this   A This   D' total A' Total 
-//          x  0  0  0  0  0  0  
-//             0  0  0  1     1 this+  
-//             0  0  1  0  1this    
-//             0  0  1  1  1 this   1 this+  
-//          x  0  1  0  0        
-//          error 0  1  0  1        
-//             0  1  1  0     1 total- 
-//             0  1  1  1     1 total-, 1 this +   
-//          x  1  0  0  0        
-//             1  0  0  1     1 this+  
-//          error 1  0  1  0        
-//          error 1  0  1  1        
-//          x  1  1  0  0        
-//          error 1  1  0  1        
-//             1  1  1  0     1 total -1  keep the old delete and remove the old add
-//             1  1  1  1     1 total-, 1 this +   
-
-//          d' = dthis - (dthis intersect a) + d // keep the old delete
-//          a' = a - (dthis intersect a) + athis // keep the new add       
-//        * */
-//       public static DataPacket combineWithIds(ICollection packets, string[] idColumns)
-//       {       
-//          if ( packets.Count == 0 )
-//          {
-//             return new DataPacket(
-//                new BlueTable(new DataTable()),
-//                new BlueTable(new DataTable()),
-//                new BlueTable(new DataTable()));                    
-//          }
-
-//          DataPacket.BlueRowIdComparator c = new DataPacket.BlueRowIdComparator(idColumns);
-
-//          CollectionHelpers.EqualDelegate ed = 
-//             new CollectionHelpers.EqualDelegate(c.blueRowIdEqualEvaluator);
-
-//          ArrayList added = new ArrayList();
-//          ArrayList deleted = new ArrayList();
-//          BlueTable dt = null;
-//          BlueTable at = null;
-//          IBlueRowCollection nt = null;
-
-//          foreach(DataPacket dp in packets)
-//          {               
-//             ArrayList oldDeleted = deleted;
-//             ArrayList oldAdded = added;
-
-//             added = new ArrayList();
-//             deleted = new ArrayList();
-//             if ( dt == null )
-//             {
-//                dt = new BlueTable(dp.schema);
-//                at = new BlueTable(dp.schema);
-//             }
-
-//             deleted.AddRange(oldDeleted);
-//             deleted.AddRange( CollectionHelpers.difference(
-//                CollectionHelpers.difference(dp.deletedRows, oldAdded, ed),
-//                oldDeleted, ed) );
-
-//             added.AddRange(dp.addedRows);
-//             added.AddRange( CollectionHelpers.difference(
-//                CollectionHelpers.difference(oldAdded, dp.deletedRows, ed),
-//                added, ed) );
-//             nt = dp.newRows;
-//          }        
-
-//          foreach ( IBlueRow dr in added )
-//          {
-//             at.addRow(dr);
-//          }
-
-//          foreach ( IBlueRow dr in deleted )
-//          {
-//             dt.addRow(dr);
-//          }
-
-//          return new DataPacket(nt,at,dt);            
-//       }
-
-//       public DataPacket deepCopy ()
-//       {
-//          return new DataPacket (new OrderedBlueTable (newRows),
-//             new OrderedBlueTable (newRows),
-//             new BlueTable (deletedRows));
-//       }
-
-//       public virtual DataPacket createImmutable ()
-//       {
-//          return 
-//          new DataPacket(
-//                newRows is IImmutableRowCollection ? newRows : new ImmutableBlueTable(newRows),
-//                addedRows, 
-//                deletedRows);
-//       }
-//       #region ICloneable Members
-
-//       public object Clone()
-//       {
-//          return MemberwiseClone();
-//       }
-
-//       #endregion
-
-//       public string toIncrementalIDString()
-//       {
-//          System.Text.StringBuilder sb = new System.Text.StringBuilder(schema.tableName);
-//          sb.Append ("\ndeleted : ");
-//          foreach (IBlueRow r in deletedRows)
-//          {
-//             sb.Append(r["id"]);
-//             sb.Append(',');
-//          }
-//          sb.Append("\nadded : ");
-//          foreach (IBlueRow r in addedRows)
-//          {
-//             sb.Append(r["id"]);
-//             sb.Append(',');
-//          }
-//          sb.Append("\n");
-//          return sb.ToString();
-//       }
-
-//       public override string ToString()
-//       {
-//          return String.Format("DataPacket, schema {0} n {1} d {2} a {3}", schema.tableName, newRows.Count, deletedRows.Count, addedRows.Count);
-//       }
-//    }
-// }
+      public override string ToString()
+      {
+         return String.Format("DataPacket, schema {0} n {1} d {2} a {3}", schema.tableName, newRows.Count, deletedRows.Count, addedRows.Count);
+      }
+   }
+}

src/DataStreamSuite/DataStreamCore/DynamicLoading/PrimitiveManager.cs

@@ -1,5 +1,4 @@
-namespace BCG
-{
+namespace BCG {
    using Bts.DataStream;
    using bts;
 
@@ -10,28 +9,26 @@ namespace BCG
    using System.Reflection;
    using System.IO;
 
-   public class PrimitiveManager
-   {
+   public class PrimitiveManager {
       private IDictionary myTypeLookupTable = new Hashtable();
       private static PrimitiveManager mySelf;
       private ArrayList myAssemblyNames = new ArrayList();
 
-      private PrimitiveManager()
-      {
+      private PrimitiveManager() {
          myLoadAllTypes();
       }
 
-      private void myLoadAllTypes()
-      {
+      private void myLoadAllTypes() {
          AppDomain currentDomain = AppDomain.CurrentDomain;
          currentDomain.AssemblyResolve += new ResolveEventHandler(myAssemblyResolver);
          loadAssembly(this.GetType().Assembly.FullName);
-
-         foreach (string assemblyName in Configuration.get<DataStreamConfig>().Assemblies)
-         {
+         var assemblies = new string[] { "datastream.dll", "sharedstreams.dll" };
+         var config_assemblies = Configuration.get<DataStreamConfig>().Assemblies;
+         bts.Log.Gen.info($"PrimitiveManager.myLoadAllTypes config_assemblies: {config_assemblies}");
+         foreach (string assemblyName in assemblies/*config_assemblies*/) {
+            bts.Log.Gen.info($"PrimitiveManager.myLoadAllTypes assemblyName: {assemblyName}");
             string resolvedAssemblyPath = assemblyName;
-            if (!System.IO.Path.IsPathRooted(assemblyName))
-            {
+            if (!System.IO.Path.IsPathRooted(assemblyName)) {
                string appPath = Path.GetDirectoryName(
                               Assembly.GetAssembly(typeof(PrimitiveManager)).CodeBase.Substring("file:///".Length));
                resolvedAssemblyPath = System.IO.Path.GetFullPath(System.IO.Path.Combine(appPath, assemblyName));
@@ -40,8 +37,7 @@ namespace BCG
          }
       }
 
-      private static Assembly myAssemblyResolver(object sender, ResolveEventArgs args)
-      {
+      private static Assembly myAssemblyResolver(object sender, ResolveEventArgs args) {
          foreach (Assembly a in AppDomain.CurrentDomain.GetAssemblies())
             if (args.Name.Equals(a.FullName))
                return a;
@@ -52,8 +48,8 @@ namespace BCG
       /// Loads all the Stream types associated with the assembly
       /// </summary>
       /// <param name="assemblyName"></param>
-      public void loadAssembly(string assemblyName)
-      {
+      public void loadAssembly(string assemblyName) {
+         bts.Log.Gen.info($"PrimitiveManager.loadAssembly assemblyName: {assemblyName}");
          if (myAssemblyNames.Contains(assemblyName))
             return;
          myAssemblyNames.Add(assemblyName);
@@ -65,13 +61,11 @@ namespace BCG
             if (!type.IsInterface
                && !type.IsAbstract
                && type.IsSubclassOf(typeof(ViewStream))
-               && type.IsPublic)
-            {
+               && type.IsPublic) {
                bool isVisible = true;
                string userRep = createDefaultName(type.Name);
                foreach (Attribute att in type.GetCustomAttributes(false))
-                  if (att is DataStreamUserRespresentation)
-                  {
+                  if (att is DataStreamUserRespresentation) {
                      DataStreamUserRespresentation dsatt = att as DataStreamUserRespresentation;
                      isVisible = dsatt.isVisible;
                      userRep = isVisible ?
@@ -79,16 +73,14 @@ namespace BCG
                         : null;
                      break;
                   }
-               if (isVisible)
-               {
-                  Log.assert(myTypeLookupTable[userRep] == null);
+               if (isVisible) {
+                  Log.assert_d(myTypeLookupTable[userRep] == null, type.FullName);
                   myTypeLookupTable[userRep] = type;
                }
             }
       }
 
-      public static string createDefaultName(string typeName)
-      {
+      public static string createDefaultName(string typeName) {
          if (!typeName.EndsWith("Stream"))
             return typeName;
          string retVal = typeName.Remove(typeName.Length - "Stream".Length, "Stream".Length);
@@ -100,8 +92,7 @@ namespace BCG
 
 
 
-      public static PrimitiveManager instance
-      {
+      public static PrimitiveManager instance {
          get { return mySelf = mySelf == null ? new PrimitiveManager() : mySelf; }
       }
 
@@ -110,8 +101,7 @@ namespace BCG
       /// </summary>
       /// <param name="friendlyName"></param>
       /// <returns></returns>
-      public string find(string friendlyName)
-      {
+      public string find(string friendlyName) {
          if (myTypeLookupTable[friendlyName] == null)
             throw new ApplicationException(friendlyName + " is not the friendly name of any of the loaded types");
          return (myTypeLookupTable[friendlyName] as Type).Name;
@@ -124,11 +114,9 @@ namespace BCG
       /// <param name="args">args can be null or an empty ICollection if the paramterless constructor
       /// is the desired one</param>
       /// <returns></returns>
-      public ViewStream build(string friendlyName, ICollection args)
-      {
+      public ViewStream build(string friendlyName, ICollection args) {
          object[] constructorArgs = null;
-         if (args != null && args.Count > 0)
-         {
+         if (args != null && args.Count > 0) {
             constructorArgs = new object[args.Count];
             args.CopyTo(constructorArgs, 0);
          }
@@ -144,8 +132,7 @@ namespace BCG
       /// Returns the name of all the primitives 
       /// </summary>
       /// <returns></returns>
-      public string[] getPrimitiveNames()
-      {
+      public string[] getPrimitiveNames() {
          string[] retVal = new string[myTypeLookupTable.Count];
          myTypeLookupTable.Keys.CopyTo(retVal, 0);
          return retVal;
@@ -155,20 +142,17 @@ namespace BCG
       /// Return the types of all the streams
       /// </summary>
       /// <returns></returns>
-      public Type[] getStreamTypes()
-      {
+      public Type[] getStreamTypes() {
          Type[] retVal = new Type[myTypeLookupTable.Count];
          myTypeLookupTable.Values.CopyTo(retVal, 0);
          return retVal;
       }
 
-      public ICollection getConstructorSigns(string primitiveName)
-      {
+      public ICollection getConstructorSigns(string primitiveName) {
          ArrayList retVal = new ArrayList();
          Log.assert(myTypeLookupTable[primitiveName] != null);
          Type t = myTypeLookupTable[primitiveName] as Type;
-         foreach (ConstructorInfo ci in t.GetConstructors())
-         {
+         foreach (ConstructorInfo ci in t.GetConstructors()) {
             string sign = "";
             sign = t.Name + " (";
             foreach (ParameterInfo pi in ci.GetParameters())
@@ -181,8 +165,7 @@ namespace BCG
          return retVal;
       }
 
-      public string getAssemblyName(string primitiveName)
-      {
+      public string getAssemblyName(string primitiveName) {
          Log.assert(myTypeLookupTable[primitiveName] != null);
          return (myTypeLookupTable[primitiveName] as Type).Assembly.GetName().Name;
       }

src/DataStreamSuite/DataStreamCore/Messaging/Accumulation/TableAccumulator.cs

@@ -42,7 +42,7 @@ namespace BCG
                Delegate.Combine (myOnUpdateDelegate, value) as TableUpdateDelegate;
             if (myStateTable != null)
                value (myStateTable, myStateTable, new BlueTable (myStateTable.schema));
-         }
+      }
          remove
          {
             // BlueEventLog.logEvent ("TableSubscriber being Unsubscribed for tag :" + myTag, BlueEventLevel.Information);
@@ -64,6 +64,7 @@ namespace BCG
 
       public void update(Stream[] streams)
       {
+         bts.Log.Gen.info($"TableAccumulator.update tag: {myTag} n_streams: {streams.Length} stream[0].len: {streams[0].Length - streams[0].Position}");
          //checking the condition as a subscriber might unsubscribe in a callback and there might be more than one
          //data element for that tag in the ViewStreamDatabase
          if (myOnUpdateDelegate != null)

src/DataStreamSuite/DataStreamCore/Messaging/ClientReceive/ClientDeserializationController.cs

@@ -3,16 +3,15 @@ using System.IO;
 using System.Collections;
 using BCG.Utilities;
 
-namespace BCG
-{
+namespace BCG {
    /// <summary>
    /// Controls (ie creates dynamically) an IClientDeserializer and then passes data to it.
    /// </summary>
-   public class ClientDeserializationController : IClientDeserializer
-   {
+   public class ClientDeserializationController : IClientDeserializer {
       private IClientDeserializer myDeserializer;
-		
-      public ClientDeserializationController () {}
+      private int _n_desers = 0;
+
+      public ClientDeserializationController() { }
 
       #region IClientDeserializer Members
 
@@ -23,42 +22,41 @@ namespace BCG
       /// <param name="streams"></param>
       /// <param name="theOps"></param>
       /// <param name="theRows"></param>
-      public void deserialize (Stream[] streams, out byte[] theOps, out Array theRows)
-      {
-         if (myDeserializer != null)
-         {
-            myDeserializer.deserialize (streams, out theOps, out theRows);
-         }
-         else 
-         {
-            Stream totalStream = UtilityMethods.getAggregatedStream (streams);
+      public void deserialize(Stream[] streams, out byte[] theOps, out Array theRows) {
+         bts.Log.Gen.info($"ClientDeserializationController.deserialize len: {streams[0].Length - streams[0].Position}");
+         if (myDeserializer != null) {
+            myDeserializer.deserialize(streams, out theOps, out theRows);
+         } else {
+            Stream totalStream = UtilityMethods.getAggregatedStream(streams);
             long initialPos = totalStream.Position;
-            BinaryReader br = new BinaryReader (totalStream);
+            BinaryReader br = new BinaryReader(totalStream);
             byte op;
-            try 
-            {
-               op = br.ReadByte ();
-            }
-            catch (EndOfStreamException)
-            {
+            try {
+               op = br.ReadByte();
+            } catch (EndOfStreamException) {
                op = Byte.MaxValue;
             }
-            if (op == StreamOpCode.create)
-            {
-               br.ReadString (); //pubsubclientdeserializer
-               string deserName = br.ReadString ();   
-               myDeserializer = Activator.CreateInstance (Type.GetType (deserName))
+            if (op == StreamOpCode.create) {
+               br.ReadString(); //pubsubclientdeserializer
+               string deserName = br.ReadString();
+               myDeserializer = Activator.CreateInstance(Type.GetType(deserName))
                   as IClientDeserializer;
                totalStream.Position = initialPos;
-               myDeserializer.deserialize (new Stream[] {totalStream}, out theOps, out theRows);
-            }
-            else
-            {
+               myDeserializer.deserialize(new Stream[] { totalStream }, out theOps, out theRows);
+            } else {
                // BlueEventLog.logEvent ("Received a non create before a create", BlueEventLevel.Warning);
-               theOps = new byte[]{};
-               theRows = new object[]{};
+               theOps = new byte[] { };
+               theRows = new object[] { };
             }
          }
+         var msgs = StreamIOMessage.assemble_msgs(theOps, theRows);
+         int i = 0;
+         foreach (var m in msgs) {
+            bts.Log.Gen.info($"ClientDeserializationController n_desers: {_n_desers} msg no: {i++}: {m}");
+         }
+         _n_desers++;
+         // log it here
+
       }
 
 

src/DataStreamSuite/DataStreamCore/Messaging/ClientReceive/ClientUniversalRowDeserializer.cs

@@ -5,61 +5,61 @@ using System.IO;
 using BCG.Utilities;
 //using BCG.Utilities.BlueConfiguration;
 
-namespace BCG
-{
+namespace BCG {
    /// <summary>
    /// Helps the ClientUniversalDeserializer in deserilizing by dealing with the deserialization process
    /// of one row. This leaves the ClientUniversalDeserializer to deserializer headers (indicating operations) 
    /// </summary>
-   internal class ClientUniversalRowDeserializer : IClientRowDeserializer
-   {
+   internal class ClientUniversalRowDeserializer : IClientRowDeserializer {
       private IBlueTableSchema mySchema;
       private int myNullMapLength = 0;
       private PrimitiveDeserializationHelper myDeserializationHelper;
       private BitArray myNullMap;
       private int[] mySerIndexToSchemaIndexMap;
-		
-      public ClientUniversalRowDeserializer (IBlueTableSchema schema)
-      {
-         myDeserializationHelper = new PrimitiveDeserializationHelper (mySchema = schema);
-         myNullMapLength = Convert.ToInt32((Math.Ceiling(Convert.ToDouble(mySchema.columnNames.Length)/8)));
-         myInitReorderSchema ();
 
-         
+      public ClientUniversalRowDeserializer(IBlueTableSchema schema) {
+         myDeserializationHelper = new PrimitiveDeserializationHelper(mySchema = schema);
+         myNullMapLength = Convert.ToInt32((Math.Ceiling(Convert.ToDouble(mySchema.columnNames.Length) / 8)));
+         myInitReorderSchema();
+
+
       }
 
       #region Schema Reordering initialization
-      private void myInitReorderSchema ()
-      {
-         int idColIndex = mySchema["id"].colNo;
-         int[] temp = new int [mySchema.columnInfo.Length];
-         foreach (ColumnInfo ci in mySchema.columnInfo)
-         {
-            temp[ci.colNo] =
-               ci.colNo == idColIndex ? 0 :
-               ci.colNo < idColIndex ? ci.colNo + 1 : ci.colNo;
+      private void myInitReorderSchema() {
+         try {
+            int idColIndex = mySchema["id"].colNo;
+            int[] temp = new int[mySchema.columnInfo.Length];
+            foreach (ColumnInfo ci in mySchema.columnInfo) {
+               temp[ci.colNo] =
+                  ci.colNo == idColIndex ? 0 :
+                  ci.colNo < idColIndex ? ci.colNo + 1 : ci.colNo;
+            }
+            mySerIndexToSchemaIndexMap = new int[temp.Length];
+            for (int i = 0; i < temp.Length; i++)
+               mySerIndexToSchemaIndexMap[temp[i]] = i;
+         } catch (Exception ex) {
+            string schema_name = mySchema == null ? "NULL" : mySchema.tableName;
+            string err_msg = $"ClientUniversalRowDeserializer.myInitReorderSchema table: {schema_name} ex: {ex}";
+            bts.Log.Gen.error(err_msg);
+            throw new ApplicationException(err_msg);
          }
-         mySerIndexToSchemaIndexMap = new int[temp.Length];
-         for (int i = 0; i < temp.Length; i ++)
-            mySerIndexToSchemaIndexMap [temp[i]] = i;
       }
       #endregion
 
       #region IClientRowDeserializer Members
 
-      public void deserializeRow (IBlueRowCollection currentState, BinaryReader br, byte op, out IBlueRow r)
-      {
-         br.ReadInt32 ();  //length information for the row not needed
-         myNullMap = new BitArray(br.ReadBytes (myNullMapLength));
-         object[] values = new object [mySchema.columnNames.Length];
-         for (int i = 0; i < values.Length; i++)
-         {
+      public void deserializeRow(IBlueRowCollection currentState, BinaryReader br, byte op, out IBlueRow r) {
+         br.ReadInt32();  //length information for the row not needed
+         myNullMap = new BitArray(br.ReadBytes(myNullMapLength));
+         object[] values = new object[mySchema.columnNames.Length];
+         for (int i = 0; i < values.Length; i++) {
             int colNo = mySerIndexToSchemaIndexMap[i];
-            values[mySerIndexToSchemaIndexMap[i]] = myNullMap[colNo] ? DBNull.Value : myDeserializationHelper.deserializeColumn (colNo, br);
+            values[mySerIndexToSchemaIndexMap[i]] = myNullMap[colNo] ? DBNull.Value : myDeserializationHelper.deserializeColumn(colNo, br);
          }
 
 
-             r = new BlueRow(mySchema, values);
+         r = new BlueRow(mySchema, values);
 
       }
 

src/DataStreamSuite/DataStreamCore/Messaging/ClientReceive/IClientDeserializer.cs

@@ -1,22 +1,149 @@
 using System;
-using System.Collections;
+using System.Collections.Generic;
 using System.IO;
+using System.Linq;
+
+namespace BCG {
+   public class StreamIOMessage {
+      public enum StreamOp {
+         Create = 0,
+         Add = 1,             //adds a single row
+         Remove = 2,          //removes a single row
+         Change = 3,          //changes a single row
+         MultipleRemoveAdd = 4,//removes and adds multiple rows
+         MultipleChange = 5 //changes multiples rows          
+      }
+      public class CreateMessage {
+         public IBlueRowCollection rows;
+         public override string ToString() {
+            string rv = "Create message ";
+            if (rows == null) {
+               rv += " rows: null";
+               return rv;
+            }
+            foreach (IBlueRow r in rows) {
+               rv += $"id: {r["id"]} ";
+            }
+            return rv;
+         }
+      }
+      public class AddMessage {
+         public IBlueRow added_row;
+      }
+      public class RemoveMessage {
+         public IBlueRow removed_row;
+      }
+      public class ChangeMessage {
+         public IBlueRow changed_row;
+      }
+      public class MultipleRemoveAddMessage {
+         public IBlueRowCollection removed;
+         public IBlueRowCollection added;
+         public override string ToString() {
+            string rv = "MultipleRemoveAdd removed: ";
+            foreach (IBlueRow r in removed) {
+               rv += $"id: {r["id"]} ";
+            }
+            rv += "added: ";
+            foreach (IBlueRow r in added) {
+               rv += $"id: {r["id"]} ";
+            }
+            return rv;
+         }
+      }
+      public class MultipleChangeMessage {
+         public IBlueRowCollection changed;
+      }
+
+      public StreamOp op;
+      public CreateMessage create_message = null;
+      public AddMessage add_message = null;
+      public RemoveMessage remove_message = null;
+      public ChangeMessage change_message = null;
+      public MultipleRemoveAddMessage multiple_remove_add_message = null;
+      public MultipleChangeMessage multiple_change_message = null;
+      public StreamIOMessage(byte op_, object data) {
+         op = (StreamIOMessage.StreamOp)(op_);
+         switch (op) {
+            case StreamIOMessage.StreamOp.Create:
+               IBlueRowCollection state = null;
+               // TODO, not sure why it can be an array and by itself
+               if (data is IBlueRowCollection) state = data as IBlueRowCollection;
+               else if (data is IBlueRowCollection[]) state = (data as IBlueRowCollection[]).ElementAt(0);
+               create_message = new CreateMessage() { rows = state };
+               break;
+            case StreamIOMessage.StreamOp.Add:
+               bts.Log.assert(false);
+               break;
+            case StreamIOMessage.StreamOp.Remove:
+               bts.Log.assert(false);
+               break;
+            case StreamIOMessage.StreamOp.Change:
+               bts.Log.assert(false);
+               break;
+            case StreamIOMessage.StreamOp.MultipleRemoveAdd:
+               IBlueRowCollection[] row_args = data as IBlueRowCollection[];
+               multiple_remove_add_message = new MultipleRemoveAddMessage() { removed = row_args[0], added = row_args[1] };
+               break;
+            case StreamIOMessage.StreamOp.MultipleChange:
+               //IBlueRowCollection[] row_args = data as IBlueRowCollection[];
+               multiple_change_message = new MultipleChangeMessage() { changed = (data as IBlueRowCollection[])[0] };
+               break;
+         }
+      }
+
+
+      public override string ToString() {
+         switch (op) {
+            case StreamIOMessage.StreamOp.Create:
+               return create_message.ToString();
+               break;
+            case StreamIOMessage.StreamOp.Add:
+               bts.Log.assert(false);
+               return String.Empty;
+               break;
+            case StreamIOMessage.StreamOp.Remove:
+               bts.Log.assert(false);
+               return String.Empty;
+               break;
+            case StreamIOMessage.StreamOp.Change:
+               bts.Log.assert(false);
+               return String.Empty;
+               break;
+            case StreamIOMessage.StreamOp.MultipleRemoveAdd:
+               return multiple_remove_add_message.ToString();
+               break;
+            case StreamIOMessage.StreamOp.MultipleChange:
+               return multiple_change_message.ToString();
+               break;
+         }
+         bts.Log.assert(false);
+         return String.Empty;
+      }
+      public static IEnumerable<StreamIOMessage> assemble_msgs(byte[] ops, Array op_data) {
+         int i = 0;
+         List<StreamIOMessage> rv = new List<StreamIOMessage>();
+         foreach (byte op in ops) {
+            object data = op_data.GetValue(i++);
+            rv.Add(new StreamIOMessage(op, data));
+         }
+         return rv;
+      }
+   }
 
-namespace BCG
-{
    /// <summary>
    /// Performs deserialization inside the client app. The client gets either the complete data set or the
    /// increments from PubSub and this interface makes sense out of them from a tabular/datastream stand point.
    /// </summary>
-   public interface IClientDeserializer 
-   {
+   public interface IClientDeserializer {
       /// <summary>
       /// deserializes the data received by the client from the pubsub
       /// </summary>
       /// <param name="serializedData">the data in byte format received from pubsub</param>
       /// <param name="theOps">the operations that the data maps onto</param>
       /// <param name="theRows">the data corresponding to the operations, is an array of IblueRowCollection[]</param>
-      void deserialize (Stream[] streams, out byte[] theOps, out Array theRows);
+      void deserialize(Stream[] streams, out byte[] theOps, out Array theRows);
    }
-
 }
+
+

src/DataStreamSuite/DataStreamCore/Messaging/ClientReceive/IClientRowDeserializer.cs

@@ -2,13 +2,11 @@ using System;
 using System.IO;
 using System.Collections;
 
-namespace BCG
-{
+namespace BCG {
    /// <summary>
    /// Deserializes one row. the current state is also provided as some deserialization schemes might use it. 
    /// </summary>
-   public interface IClientRowDeserializer
-   {
-      void deserializeRow (IBlueRowCollection currentState, BinaryReader br, byte op, out IBlueRow r);
+   public interface IClientRowDeserializer {
+      void deserializeRow(IBlueRowCollection currentState, BinaryReader br, byte op, out IBlueRow r);
    }
 }

src/DataStreamSuite/DataStreamCore/Messaging/Publish/PubTablePublisher.cs

@@ -16,7 +16,7 @@ namespace BCG {
 
       public PubTablePublisher(string tag, PublisherCore publisherCore) {
          _tag = tag;
-         bts.Log.Gen.info($"PubTablePublisher created for tag: {tag}");
+         bts.Log.Gen.info($"PubTablePublisher.cons created for tag: {tag}");
          myPubCore = publisherCore;
          mySerializer = new BlueDataSerializationController();
       }
@@ -54,10 +54,14 @@ namespace BCG {
                                  out data);
          bts.Log.Gen.info($"PubTablePublisher.createTable tag: {_tag} rows: {rows.Count} data: {data.Length}");
          myPublish(data, rows.schema.tableName);
+         // byte[] ops;
+         // Array rows_ds;
+         // _test_deserializer.deserialize(new Stream[] { new MemoryStream(data) }, out ops, out rows_ds);
       }
 
+      //private ClientDeserializationController _test_deserializer = new ClientDeserializationController();
       public virtual void batchRemoveAdd(IBlueRowCollection delRows, IBlueRowCollection addRows) {
-         byte[] data;
+         byte[] data = null;
          if (myIsRealChange(delRows, addRows))
             batchChange(addRows);
          else {
@@ -66,6 +70,9 @@ namespace BCG {
                                     out data);
             myPublish(data, delRows.schema.tableName);
          }
+         // byte[] ops;
+         // Array rows_ds;
+         // _test_deserializer.deserialize(new Stream[] { new MemoryStream(data) }, out ops, out rows_ds);
       }
 
       public virtual void batchChange(IBlueRowCollection rows) {

src/DataStreamSuite/DataStreamCore/Misc/IPubSubRouter.cs

@@ -1,20 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-
-namespace BCG
-{
-   public delegate void PubSubTagURLChangeDelegate(List<string> tagsMoving, string newURL);
-   
-   public interface IPubSubRouter
-   {
-
-      event PubSubTagURLChangeDelegate onSubURLTagRouteChange;
-      event PubSubTagURLChangeDelegate onPubURLTagRouteChange;
-      List<string> getAllPubSubSubURLs();
-      List<string> getAllPubSubPubURLs();
-      string getSubURLForTag(string tag);
-      string getPubURLForTag(string tag);
-   }
-}

src/DataStreamSuite/DataStreamExpressions/DataStreamExpressionGrammar.y

@@ -23,6 +23,7 @@
 
 %token BOOLEAN_CONSTANT, INTEGER_CONSTANT, REAL_CONSTANT, DATE_TIME_CONSTANT, CS_STRING_CONSTANT, NULL_CONSTANT
 %token PARENTHESIS_OPEN, PARENTHESIS_CLOSE, COMMA, IDENTIFIER, EQUALS, QUOTE_OPEN, QUOTE_CLOSE
+%token LINE_COMMENT
 
 %nonassoc EQUALS
 
@@ -49,6 +50,12 @@ Statement :
    | IDENTIFIER EQUALS Statement {
       $$ = new Assignment($1.Identifier, $3);
    }
+   | LINE_COMMENT Statement {
+      $$ = $2;
+   }
+   | Statement LINE_COMMENT {
+      $$ = $1;
+   }
    ;
 
 Arguments :

src/DataStreamSuite/DataStreamExpressions/DataStreamExpressionTokens.lex

@@ -26,6 +26,9 @@ Comma                    ,
 QuoteOpen                \[
 QuoteClose               \]
 
+/* Comments */
+LineComment \/\/[^\n\r]*(\n|\r|\r\n)
+
 %%
 
 {Equals} {
@@ -92,4 +95,8 @@ QuoteClose               \]
    return (int)DataStreamExpressionToken.IDENTIFIER;
 }
 
+{LineComment} {
+   return (int)DataStreamExpressionToken.LINE_COMMENT;
+}
+
 %%

src/DataStreamSuite/DataStreamExpressions/DataStreamExpressions.csproj

@@ -8,7 +8,7 @@
 
   <ItemGroup>
     <PackageReference Include="Google.Protobuf" Version="3.24.3" />
-    <PackageReference Include="YaccLexTools" Version="1.2.0" />
+    <PackageReference Include="YaccLexTools" Version="1.2.2" />
   </ItemGroup>
 
   <ItemGroup>

src/DataStreamSuite/DataStreamExpressions/PrimitiveExpression.cs

@@ -48,14 +48,26 @@ public class PrimitiveExpression : StatementExpression {
       return PrimitiveManager.instance.build(myName, resolvedArgs);
    }
 
+   string myPrintSingleArg(int atColumn, object? o, IList<string> activeBindings) {
+      /// Unwrap <see cref="Argument"/> to get its underlying value
+      while (o is Argument arg) {
+         o = arg.Obj;
+         // Safeguard against infinite loop
+         if (ReferenceEquals(o, arg)) {
+            throw new ArgumentException(
+               $"Detected circular reference in argument " +
+               $"('{nameof(arg)}.{nameof(arg.Obj)}' is '{nameof(arg)}' itself)");
+         }
+      }
 
-   string myPrintSingleArg(int atColumn, object o, IList<string> activeBindings) {
+      string result = new string(' ', atColumn);
+      if (o is null) {
+         return result;
+      }
       if (o is StatementExpression)
          return new string(' ', atColumn) +
             ((o as StatementExpression)?.print(atColumn, activeBindings) ?? string.Empty);
       else {
-         string result = new string(' ', atColumn);
-
          if (o is string)
             result += makeCSString((string)o);
          else if (o is DateTime)