cleanup: Remove empty file (clearly added by accident)

This arg doesn't seem to have a purpose. It was prob leftover from
testing or something

.editorconfig

@@ -207,17 +207,23 @@ dotnet_naming_symbols.parameters.applicable_accessibilities = public,internal,pr
 dotnet_naming_symbols.private_symbols.applicable_kinds = property,method,field,event,delegate
 dotnet_naming_symbols.private_symbols.applicable_accessibilities = protected,private
 
+# local symbols
+dotnet_naming_symbols.local_symbols.applicable_kinds = local
+
+# parameter symbols
+dotnet_naming_symbols.parameter_symbols.applicable_kinds = parameter
+
 # Naming styles
 
-dotnet_naming_style.snake_case.required_prefix =
-dotnet_naming_style.snake_case.required_suffix =
-dotnet_naming_style.snake_case.word_separator = _
-dotnet_naming_style.snake_case.capitalization = all_lower
+dotnet_naming_style.pascal_case.required_prefix =
+dotnet_naming_style.pascal_case.required_suffix =
+dotnet_naming_style.pascal_case.word_separator =
+dotnet_naming_style.pascal_case.capitalization = pascal_case
 
-dotnet_naming_style.private_snake_case.required_prefix = _
-dotnet_naming_style.private_snake_case.required_suffix =
-dotnet_naming_style.private_snake_case.word_separator = _
-dotnet_naming_style.private_snake_case.capitalization = all_lower
+dotnet_naming_style.camel_case.required_prefix =
+dotnet_naming_style.camel_case.required_suffix =
+dotnet_naming_style.camel_case.word_separator =
+dotnet_naming_style.camel_case.capitalization = camel_case
 
 dotnet_naming_style.user_types.required_prefix =
 dotnet_naming_style.user_types.required_suffix =
@@ -229,6 +235,10 @@ dotnet_naming_style.interface.required_suffix =
 dotnet_naming_style.interface.word_separator =
 dotnet_naming_style.interface.capitalization = pascal_case
 
+dotnet_naming_style.local.capitalization = camel_case
+
+dotnet_naming_style.parameter.capitalization = camel_case
+
 # rules
 dotnet_naming_rule.user_types.symbols = user_types
 dotnet_naming_rule.user_types.style = user_types
@@ -238,14 +248,18 @@ dotnet_naming_rule.interfaces.symbols = interface
 dotnet_naming_rule.interfaces.style = interface_style
 dotnet_naming_rule.interfaces.severity = suggestion
 
-dotnet_naming_rule.public_members_snake_case.symbols = public_symbols
-dotnet_naming_rule.public_members_snake_case.style = snake_case
-dotnet_naming_rule.public_members_snake_case.severity = suggestion
+dotnet_naming_rule.public_members.symbols = public_symbols
+dotnet_naming_rule.public_members.style = pascal_case
+dotnet_naming_rule.public_members.severity = suggestion
 
-dotnet_naming_rule.private_members_snake_case.symbols = private_symbols
-dotnet_naming_rule.private_members_snake_case.style = private_snake_case
-dotnet_naming_rule.private_members_snake_case.severity = suggestion
+dotnet_naming_rule.private_members.symbols = private_symbols
+dotnet_naming_rule.private_members.style = camel_case
+dotnet_naming_rule.private_members.severity = suggestion
 
-dotnet_naming_rule.parameters.symbols = parameters
-dotnet_naming_rule.parameters.style = snake_case
+dotnet_naming_rule.variables_are_camel_case.severity = suggestion
+dotnet_naming_rule.variables_are_camel_case.symbols = local_symbols
+dotnet_naming_rule.variables_are_camel_case.style = local
+
+dotnet_naming_rule.parameters.symbols = parameter_symbols
+dotnet_naming_rule.parameters.style = parameter
 dotnet_naming_rule.parameters.severity = suggestion

.gitmodules

@@ -1,6 +1,6 @@
 [submodule "externals"]
 	path = externals
-	url = git@bitbucket.org:bluetradesys/externals.git
+	url = https://x-token-auth:ATCTT3xFfGN0h_ENnUSfEAIzbfVzkQPLG26cIli50MtcTwZ7VEc8lin5tJYqibjlBJ9PM9R642Ra5GjiL52TBfbO8KeUBT0UoMT7gLQHL2Y1TkW9yZr6NkvsoDkSl49DeD4Ijiu4_0u4qEm4oMVDDg2_fB059-uOWOo7ZL94tGZET8CSVpFIGvs=B0E03660@bitbucket.org/bluetradesys/externals.git
 [submodule "vcpkg"]
 	path = vcpkg
 	url = https://github.com/microsoft/vcpkg.git

.gitpod.yml

@@ -0,0 +1,49 @@
+# This configuration file was automatically generated by Gitpod.
+# Please adjust to your needs (see https://www.gitpod.io/docs/introduction/learn-gitpod/gitpod-yaml)
+# and commit this file to your remote git repository to share the goodness with others.
+
+# Learn more from ready-to-use templates: https://www.gitpod.io/docs/introduction/getting-started/quickstart
+
+image: gitpod/workspace-dotnet-8
+tasks:
+  - name: Install Deps
+    init: |
+      (
+        set -e
+        sudo install-packages rapidjson-dev
+        sudo install-packages libssh2-1-dev
+        sudo install-packages openssh-server
+        sudo install-packages liblttng-ust-dev
+        sudo install-packages libpcap0.8-dev
+        sudo install-packages ccache
+        sudo ln -s $(which ccache) /usr/local/bin/clang
+        sudo ln -s $(which ccache) /usr/local/bin/clang++
+        sudo ln -s $(which ccache) /usr/local/bin/clang-17
+        sudo ln -s $(which ccache) /usr/local/bin/clang++-17
+        sudo ln -s $(which ccache) /usr/local/bin/gcc
+        sudo ln -s $(which ccache) /usr/local/bin/g++
+        sudo ln -s $(which ccache) /usr/local/bin/gcc-12
+        sudo ln -s $(which ccache) /usr/local/bin/g++-12
+        if [ -e externals/src/emumba/install_emumba-deribit-connector.sh ]; then
+          externals/src/emumba/install_emumba-deribit-connector.sh
+        fi
+      )
+  - name: Setup Python venv
+    init: |
+      python -m pip install --upgrade pip
+      python -m venv .venv
+      . .venv/bin/activate
+      python -m pip install --upgrade pip
+      pip install -r requirements.txt
+
+ports:
+  - name: sparkd config
+    port: 8000
+    onOpen: notify
+  - name: sparkd bus
+    port: 8001
+
+gitConfig:
+  alias.st: "status"
+  status.short: "true"
+  core.pager: "less -FXRS"

docker/sparkd/dev/Dockerfile

@@ -1,42 +1,46 @@
 FROM ubuntu:latest
 
 ARG DEBIAN_FRONTEND=noninteractive
-ENV TZ=America/New_York
 
-# light deps (should be quick to download/install)
+# Light Deps - should be quick to download/install.
+# Longer running procs should be executed in individual RUNs.
 RUN apt-get update && apt-get install -y \
-    ca-certificates \
-    curl \
-    gnupg \
-    liblttng-ust-dev \
-    libpcap0.8-dev \
-    locales \
-    ninja-build \
-    software-properties-common \
-    sqlite3 \
-    tzdata
+   build-essential \
+   ca-certificates \
+   curl \
+   gnupg \
+   liblttng-ust-dev \
+   libpcap0.8-dev \
+   locales \
+   ninja-build \
+   software-properties-common \
+   sqlite3 \
+   tzdata
 
-# clang
+# Clang 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/jammy/ llvm-toolchain-jammy-17 main" \
+   | tee -a "/etc/apt/sources.list.d/llvm.list" \
+   && apt-get update \
+   && apt-get install -y \
+   clang-17 \
+   clang-format-17 \
+   clangd-17
+
+# G++
 RUN apt-get update && apt-get install -y \
-    clang-13 \
-    clang-format-13 \
-    clangd-13 \
-    clang-15 \
-    clang-format-15 \
-    clangd-15
+   g++
 
-# g++
+# Python
 RUN apt-get update && apt-get install -y \
-    g++-11 \
-    g++-12
+   python3-pip \
+   python3-venv \
+   && python3 -m pip install --upgrade pip
 
-# python
-RUN apt-get update && apt-get install -y \
-    python3-pip \
-    python3-venv \
-    && python3 -m pip install --upgrade pip
-
-# dotnet
+# Dotnet
 RUN \
    curl -fsSLO "https://packages.microsoft.com/config/ubuntu/$(lsb_release -rs)/packages-microsoft-prod.deb" \
    && dpkg -i packages-microsoft-prod.deb \
@@ -44,89 +48,65 @@ RUN \
    && apt-get update \
    && apt-get install -y dotnet-sdk-8.0
 
-# ssh
+# SSH
 RUN apt-get update && apt-get install -y \
-    libssh2-1-dev \
-    openssh-server
+   libssh2-1-dev \
+   openssh-server
 
-# cmake
+# 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 \
-    && 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
+   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
 
-# node
+# 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_$node_major.x nodistro main" \
-    | tee /etc/apt/sources.list.d/nodesource.list \
-    && apt-get update \
-    && apt-get install -y nodejs
+   && curl -fsSL https://deb.nodesource.com/gpgkey/nodesource-repo.gpg.key \
+   | gpg --dearmor -o /etc/apt/keyrings/nodesource.gpg \
+   && echo "deb [signed-by=/etc/apt/keyrings/nodesource.gpg] https://deb.nodesource.com/node_$node_major.x nodistro main" \
+   | tee /etc/apt/sources.list.d/nodesource.list \
+   && apt-get update \
+   && apt-get install -y nodejs
 
-# ccache is done here so that ccache sees clang++ installed, not clang-10
-RUN apt-get update && apt-get install -y \
-    ccache 
-
-# emumba (light deps)
-RUN apt-get update && apt-get install -y \
-    build-essential \
-    doxygen \
-    python3-sphinx \
-    graphviz \
-    libgtest-dev \
-    libssl-dev \
-    rapidjson-dev \
-    zlib1g-dev \
-    pkg-config
-
-# emumba (boost)
-RUN apt-get update && apt-get install -y \
-    libboost-filesystem-dev \
-    libboost-program-options-dev \
-    libboost-test-dev \
-    libboost-date-time-dev
-
-# dev utils
+# Dev Utils
 RUN apt-get update && apt-get install -y \ 
-    fish \
-    git-all \
-    sudo \
-    vim \
-    wget
+   ccache \
+   fish \
+   gdb \
+   git-all \
+   sudo \
+   vim
 
-# set up default executables (update-alternatives)
+# Set up default executables (update-alternatives)
 RUN \
-    update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-15 100; \
-    update-alternatives --install /usr/bin/clang clang /usr/bin/clang-15 100; \
-    update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-15 100; \
-    update-alternatives --install /usr/bin/clangd clangd /usr/bin/clangd-15 100; \
-    update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-12 100; \
-    update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 100
+   update-alternatives --install /usr/bin/clang++ clang++ /usr/bin/clang++-17 100; \
+   update-alternatives --install /usr/bin/clang clang /usr/bin/clang-17 100; \
+   update-alternatives --install /usr/bin/clang-format clang-format /usr/bin/clang-format-17 100; \
+   update-alternatives --install /usr/bin/clangd clangd /usr/bin/clangd-17 100; \
+   update-alternatives --install /usr/bin/g++ g++ /usr/bin/g++-12 100; \
+   update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-12 100
 
 # 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-13; \
-    ln -s /usr/bin/ccache /usr/local/bin/clang++-13; \
-    ln -s /usr/bin/ccache /usr/local/bin/clang-15; \
-    ln -s /usr/bin/ccache /usr/local/bin/clang++-15; \
-    ln -s /usr/bin/ccache /usr/local/bin/gcc; \
-    ln -s /usr/bin/ccache /usr/local/bin/g++; \
-    ln -s /usr/bin/ccache /usr/local/bin/gcc-11; \
-    ln -s /usr/bin/ccache /usr/local/bin/g++-11; \
-    ln -s /usr/bin/ccache /usr/local/bin/gcc-12; \
-    ln -s /usr/bin/ccache /usr/local/bin/g++-12
+   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-13; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang++-13; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang-15; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang++-15; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang-17; \
+   ln -s /usr/bin/ccache /usr/local/bin/clang++-17; \
+   ln -s /usr/bin/ccache /usr/local/bin/gcc; \
+   ln -s /usr/bin/ccache /usr/local/bin/g++; \
+   ln -s /usr/bin/ccache /usr/local/bin/gcc-11; \
+   ln -s /usr/bin/ccache /usr/local/bin/g++-11; \
+   ln -s /usr/bin/ccache /usr/local/bin/gcc-12; \
+   ln -s /usr/bin/ccache /usr/local/bin/g++-12
 
 RUN locale-gen en_US.UTF-8
 
@@ -135,11 +115,11 @@ 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")" \
-    "$docker_user"
+   groupadd -g "$docker_uid" "$docker_user" \
+   && useradd \
+   -m \
+   -u "$docker_uid" \
+   -g "$docker_uid" \
+   -G sudo \
+   --password "$(openssl passwd -1 "$docker_pass")" \
+   "$docker_user"

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/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/Bts.DataStream.Websocket/Bts.DataStream.Websocket.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>

src/DataStreamSuite/Bts.DataStream.Websocket/DataSync.cs

@@ -1,229 +1,301 @@
-namespace Bts.DataStream.Websocket;
-
-using BCG;
-
-using bts;
-using bts.api.core;
-using bts.collections;
-
-using Bts.DataStreamExpressions;
-using Bts.Websocket;
-
-using mbts.utils;
-
-using Spark.Core.Disposables;
-
-using System.Reactive.Subjects;
-using System.Text.Json;
-using System.Text.Json.Nodes;
-
-/// <summary>
-/// Represents an I/O model (<see cref="ISubject{TSource, TResult}"/>), that accepts websocket
-/// requests (from clients) as input, and emits data/notifications (to clients) as output.
-/// This class's chief role is managing data subscriptions to sparkd on the clients' behalf.
-/// </summary>
-public class DataSync(ServiceContext serviceCtx, JsonSerializerOptions? serializerOpts = null) :
-   ISubject<WebsocketConnectionUpdate, IEnumerable<WebsocketOutgoingMessage>> {
-   readonly ServiceContext serviceCtx = serviceCtx;
-   readonly JsonSerializerOptions serializerOpts = serializerOpts ?? JsonSerializerOptions.Default;
-   readonly Dictionary<WebsocketClientID, List<ClientSubscription>> clients = [];
-   readonly object lockObj = new();
-
-   event Action<IEnumerable<WebsocketOutgoingMessage>>? requestSend;
-
-   public void OnCompleted() =>
-      Log.Api.info("DataSync incoming request stream has completed.");
-
-   public void OnError(Exception error) =>
-      Log.Api.error($"DataSync error: {error}");
-
-   public void OnNext(WebsocketConnectionUpdate value) {
-      switch (value.Type) {
-         case WebsocketConnectionUpdateType.IncomingMessage:
-            onIncomingMessage(value.IncomingMessage);
-            break;
-         case WebsocketConnectionUpdateType.Connect:
-            onConnect(value.Connect);
-            break;
-         case WebsocketConnectionUpdateType.Disconnect:
-            onDisconnect(value.Disconnect);
-            break;
-         default:
-            Log.assert(false, $"Unexpected WebsocketConnectionUpdate type: {value.Type}");
-            break;
-      }
-   }
-
-   public IDisposable Subscribe(IObserver<IEnumerable<WebsocketOutgoingMessage>> observer) {
-      lock (lockObj) {
-         requestSend += observer.OnNext;
-         return Disposable.Create(dispose);
-      }
-      void dispose() {
-         lock (lockObj) {
-            requestSend -= observer.OnNext;
-         }
-      }
-   }
-
-   static JsonRpcId? extractRpcId(string messageBody) {
-      try {
-         return JsonNode.Parse(messageBody)
-            ?.AsObject()
-            ?.GetValueOrDefault("id")
-            ?.Deserialize<JsonRpcId>();
-      } catch {
-         return null;
-      }
-   }
-
-   void onConnect(WebsocketConnectNotification notification) {
-      var id = notification.Id;
-      lock (lockObj) {
-         clients.Add(id, new());
-      }
-      Log.Api.info($"DataStreamWebsocketDataSync client connected. clientId: {notification.Id}");
-      if (notification.Message is not null) {
-         onIncomingMessage(notification.Message);
-      }
-   }
-
-   void onDisconnect(WebsocketDisconnectNotification notification) {
-      Log.Api.warn($"DataStreamWebsocketDataSync client disconnected. clientId: {notification.Id}");
-      unsubscribeAll(notification.Id);
-      clients.Remove(notification.Id);
-   }
-
-   void onIncomingMessage(WebsocketIncomingMessage message) {
-      var id = message.sender_client_id;
-      if (!JsonRpcRequest.TryDeserialize(message, out var req, out var err)) {
-         onBadRequest(message, err);
-         return;
-      }
-      switch (req.Method!.ToLower()) {
-         case "subscribe":
-            subscribe(id, req);
-            break;
-         case "unsubscribe":
-            unsubscribe(id, req);
-            break;
-         case "unsubscribe_all":
-            unsubscribeAll(id);
-            break;
-         default:
-            Log.Api.error($"Received request of unknown type: {req}");
-            break;
-      }
-   }
-
-   void sendNotification<T>(WebsocketClientID id, string method, T rpcParams) {
-      var rpcNotification = JsonRpcRequest.CreateNotification(method, rpcParams);
-      var rpcNotificationStr = JsonSerializer.Serialize(rpcNotification, serializerOpts);
-      send(new WebsocketOutgoingMessage[] { new(id, rpcNotificationStr) });
-   }
-
-   void sendResponse<T>(WebsocketClientID id, JsonRpcId rpcId, T rpcParams) {
-      var rpcRes = JsonRpcResponse.Create(rpcId, rpcParams);
-      var rpcResStr = JsonSerializer.Serialize(rpcRes, serializerOpts);
-      send(new WebsocketOutgoingMessage[] { new(id, rpcResStr )});
-   }
-
-   void sendError<T>(WebsocketClientID id, JsonRpcId rpcId, JsonRpcError<T> error) {
-      var rpcRes = JsonRpcResponse.CreateError(rpcId, error);
-      var rpcResStr = JsonSerializer.Serialize(rpcRes, serializerOpts);
-      send(new WebsocketOutgoingMessage[] { new(id, rpcResStr) });
-   }
-
-   bool send(IEnumerable<WebsocketOutgoingMessage> messages) {
-      lock (lockObj) {
-         if (requestSend is null) {
-            Log.Api.warn(
-               $"Unable to send message(s) because '{nameof(requestSend)}' handler is null");
-            return false;
-         }
-         requestSend(messages);
-         return true;
-      }
-   }
-
-   void subscribe(WebsocketClientID id, JsonRpcRequest<JsonObject?> req) {
-      var subParams = req.Params!.Deserialize<SubscriptionParams>()!;
-      var exp = DataStreamExpressionsInterpreter.Evaluate(subParams.Query!);
-      var stream = exp.getView(new Dictionary<string, StatementExpression>(0));
-      var sub = new ClientSubscription(id, subParams, Disposable.Create(dispose));
-      lock (lockObj) {
-         clients[id].Add(sub);
-         sendResponse(id, req.Id!.Value, req.Params);
-         stream.onChange += onChange;
-      }
-
-      void onChange(object? newValue) {
-         var dp = ExceptionAssert.of_type<DataPacket>(newValue);
-         var rpcParams = new {
-            addedRows = dp.addedRows,
-            deletedRows = dp.deletedRows
-         };
-         sendNotification(id, "subscription", rpcParams);
-      }
-
-      void dispose() =>
-         stream.onChange -= onChange;
-   }
-
-   void unsubscribe(WebsocketClientID id, JsonRpcRequest<JsonObject?> req) {
-      var subParams = req.Params!.Deserialize<SubscriptionParams>();
-      var subParamsStr = JsonSerializer.Serialize(subParams, serializerOpts);
-      // Minimize amount of code inside lock (just need it to find/remove the subscription)
-      List<ClientSubscription>? subs = null;
-      ClientSubscription? sub = null;
-      lock (lockObj) {
-         subs = clients.GetValueOrDefault(id);
-         subs?.TryRemoveFirst(s => s!.Params.Equals(subParams), out sub);
-      }
-      if (subs is null) {
-         // Didn't find client (log/throw).
-         var msg = $"Unable to unsubscribe: did not find client. Id: {id}.\nParams:\n{subParamsStr}";
-         Log.Api.error(msg);
-         throw new Exception(msg);
-      }
-      if (sub is null) {
-         // Found client, but didn't find subscription (log/throw).
-         var msg = $"Unable to unsubscribe: did not find the specified subscription. " +
-            $"Id: {id}. Request:\n{subParams}";
-         Log.Api.error(msg);
-         throw new Exception(msg);
-      }
-      // Found client and subscription (dispose/remove subscription).
-      Log.Api.info($"Unsubscribing client. Id: {id}.\nParams:\n{subParamsStr}");
-      sub.Dispose();
-   }
-
-   void unsubscribeAll(WebsocketClientID id) {
-      lock (lockObj) {
-         if (!clients.TryGetValue(id, out var subs)) {
-            throw new Exception(
-               $"Unable to unsubscribe: did not find client with id {id}");
-         }
-         subs.DisposeAll();
-         subs.Clear();
-      }
-   }
-
-   void onBadRequest(WebsocketIncomingMessage req, string? errorMsg) {
-      var rpcId = extractRpcId(req.message_body);
-      var logMsg = $"Recieved invalid request:\n{req.message_body}";
-      if (errorMsg is not null) {
-         logMsg += $"\n\n**Exception**\n{errorMsg}";
-      }
-      Log.Api.error(logMsg);
-      if (rpcId is null) {
-         return;
-      }
-      // Send error back to client
-      var rpcErr = JsonRpcError.Create(
-         (long)JsonRpcErrorCode.InvalidRequest,
-         $"Received invalid request: {errorMsg ?? "unknown error"}",
-         req.message_body);
-      sendError(req.sender_client_id, rpcId.Value, rpcErr);
-   }
-}
+namespace Bts.DataStream.Websocket;
+
+using BCG;
+
+using bts;
+using bts.api.core;
+using bts.collections;
+
+using Bts.DataStreamExpressions;
+using Bts.Websocket;
+
+using mbts.utils;
+
+using Spark.Core.Disposables;
+using Spark.Core.Json;
+
+using System.Buffers;
+using System.Reactive.Subjects;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+/// <summary>
+/// Represents an I/O model (<see cref="ISubject{TSource, TResult}"/>), that accepts websocket
+/// requests (from clients) as input, and emits data/notifications (to clients) as output.
+/// This class's chief role is managing data subscriptions to sparkd on the clients' behalf.
+/// </summary>
+public class DataSync(JsonSerializerOptions? serializerOpts = null) :
+   ISubject<WebsocketConnectionUpdate, IEnumerable<WebsocketOutgoingMessage>> {
+   protected readonly object lockObj = new();
+   readonly JsonSerializerOptions serializerOpts = serializerOpts ?? JsonSerializerOptions.Default;
+   readonly Dictionary<WebsocketClientID, List<ClientSubscription>> clients = [];
+
+   event Action<IEnumerable<WebsocketOutgoingMessage>>? requestSend;
+
+   public void OnCompleted() =>
+      Log.Api.info("DataSync incoming request stream has completed.");
+
+   public void OnError(Exception error) =>
+      Log.Api.error($"DataSync error: {error}");
+
+   public void OnNext(WebsocketConnectionUpdate value) {
+      switch (value.Type) {
+         case WebsocketConnectionUpdateType.IncomingMessage:
+            onIncomingMessage(value.IncomingMessage);
+            break;
+         case WebsocketConnectionUpdateType.Connect:
+            onConnect(value.Connect);
+            break;
+         case WebsocketConnectionUpdateType.Disconnect:
+            onDisconnect(value.Disconnect);
+            break;
+         default:
+            Log.assert(false, $"Unexpected WebsocketConnectionUpdate type: {value.Type}");
+            break;
+      }
+   }
+
+   public IDisposable Subscribe(IObserver<IEnumerable<WebsocketOutgoingMessage>> observer) {
+      lock (lockObj) {
+         requestSend += observer.OnNext;
+         return Disposable.Create(Dispose);
+      }
+      void Dispose() {
+         lock (lockObj) {
+            requestSend -= observer.OnNext;
+         }
+      }
+   }
+
+   static JsonRpcId? extractRpcId(string messageBody) {
+      try {
+         return JsonNode.Parse(messageBody)
+            ?.AsObject()
+            ?.GetValueOrDefault("id")
+            ?.Deserialize<JsonRpcId>();
+      } catch {
+         return null;
+      }
+   }
+
+   static string getRpcNotification(DataPacket dp) {
+      using (var buffer = new MemoryStream())
+      using (var writer = new Utf8JsonWriter(buffer))
+      using (writer.WriteObject()) {
+         writer.WriteString("method", "subscription");
+         using (writer.WriteObject("params")) {
+            writer.Write("tableName", dp.schema.tableName);
+            writer.Write("columns", dp.schema.columnInfo);
+            var cellJsonFactories = dp.schema.columnInfo.Select(getCellJsonFactory).ToList();
+            using (writer.WriteArray("added")) {
+               foreach (IBlueRow row in (dp.addedRows?.Cast<IBlueRow>()).empty_if_null()) {
+                  using (writer.WriteObject()) {
+                     for (int i = 0; i < cellJsonFactories.Count; i++) {
+                        writer.Write(dp.schema.columnInfo[i].colName, cellJsonFactories[i](row));
+                     }
+                  }
+               }
+            }
+            using (writer.WriteArray("deleted")) {
+               foreach (IBlueRow row in (dp.deletedRows?.Cast<IBlueRow>()).empty_if_null()) {
+                  using (writer.WriteObject()) {
+                     for (int i = 0; i < cellJsonFactories.Count; i++) {
+                        writer.Write(dp.schema.columnInfo[i].colName, cellJsonFactories[i](row));
+                     }
+                  }
+               }
+            }
+         }
+         writer.WriteString("jsonrpc", "2.0");
+         writer.Flush();
+         return Encoding.UTF8.GetString(buffer.ToArray());
+      }
+   }
+
+   static Func<IBlueRow, JsonNode?> getCellJsonFactory(ColumnInfo colInfo) {
+      var t = colInfo.colType;
+      if (t == typeof(int)) {
+         return NullCheckWrapper(v => (int)v);
+      }
+      if (t == typeof(uint)) {
+         return NullCheckWrapper(v => (uint)v);
+      }
+      if (t == typeof(long)) {
+         return NullCheckWrapper(v => (long)v);
+      }
+      if (t == typeof(ulong)) {
+         return NullCheckWrapper(v => (ulong)v);
+      }
+      if (t == typeof(short)) {
+         return NullCheckWrapper(v => (short)v);
+      }
+      if (t == typeof(ushort)) {
+         return NullCheckWrapper(v => (ushort)v);
+      }
+      if (t == typeof(double)) {
+         return NullCheckWrapper(v => (double)v);
+      }
+      if (t == typeof(float)) {
+         return NullCheckWrapper(v => (float)v);
+      }
+      if (t == typeof(bool)) {
+         return NullCheckWrapper(v => (bool)v);
+      }
+      return NullCheckWrapper(v => (string)v);
+
+      Func<IBlueRow, JsonNode?> NullCheckWrapper(Func<object, JsonNode> toJson) =>
+         r => {
+            var obj = r[colInfo.colNo];
+            if (obj is null) {
+               return null;
+            }
+            return toJson(obj);
+         };
+   }
+
+   void onConnect(WebsocketConnectNotification notification) {
+      var id = notification.Id;
+      lock (lockObj) {
+         clients.Add(id, []);
+      }
+      Log.Api.info($"DataStreamWebsocketDataSync client connected. clientId: {notification.Id}");
+      if (notification.Message is not null) {
+         onIncomingMessage(notification.Message);
+      }
+   }
+
+   void onDisconnect(WebsocketDisconnectNotification notification) {
+      Log.Api.warn($"DataStreamWebsocketDataSync client disconnected. clientId: {notification.Id}");
+      unsubscribeAll(notification.Id);
+      clients.Remove(notification.Id);
+   }
+
+   void onIncomingMessage(WebsocketIncomingMessage message) {
+      var id = message.sender_client_id;
+      if (!JsonRpcRequest.TryDeserialize(message, out var req, out var err)) {
+         onBadRequest(message, err);
+         return;
+      }
+      switch (req.Method!.ToLower()) {
+         case "subscribe":
+            subscribe(id, req);
+            break;
+         case "publish":
+            Log.Api.error("DataStreamWebsocket api 'publish' not implemented.");
+            // TODO
+            break;
+         case "unsubscribe":
+            unsubscribe(id, req);
+            break;
+         case "unsubscribe_all":
+            unsubscribeAll(id);
+            break;
+         default:
+            Log.Api.error($"Received request of unknown type: {req}");
+            break;
+      }
+   }
+
+   void sendResponse<T>(WebsocketClientID id, JsonRpcId rpcId, T rpcParams) {
+      var rpcRes = JsonRpcResponse.Create(rpcId, rpcParams);
+      var rpcResStr = JsonSerializer.Serialize(rpcRes, serializerOpts);
+      send([new(id, rpcResStr)]);
+   }
+
+   void sendError<T>(WebsocketClientID id, JsonRpcId rpcId, JsonRpcError<T> error) {
+      var rpcRes = JsonRpcResponse.CreateError(rpcId, error);
+      var rpcResStr = JsonSerializer.Serialize(rpcRes, serializerOpts);
+      send([new(id, rpcResStr)]);
+   }
+
+   bool send(IEnumerable<WebsocketOutgoingMessage> messages) {
+      lock (lockObj) {
+         if (requestSend is null) {
+            Log.Api.warn(
+               $"Unable to send message(s) because '{nameof(requestSend)}' handler is null");
+            return false;
+         }
+         requestSend(messages);
+         return true;
+      }
+   }
+
+   void subscribe(WebsocketClientID id, JsonRpcRequest<JsonObject?> req) {
+      var subParams = req.Params!.Deserialize<SubscriptionParams>()!;
+      var exp = DataStreamExpressionsInterpreter.Evaluate(subParams.Query!);
+      var stream = exp.getView(new Dictionary<string, StatementExpression>(0));
+      var sub = new ClientSubscription(id, subParams, Disposable.Create(Dispose));
+      lock (lockObj) {
+         clients[id].Add(sub);
+         sendResponse(id, req.Id!.Value, req.Params);
+         stream.onChange += OnChange;
+      }
+
+      void OnChange(object? newValue) {
+         var dp = ExceptionAssert.of_type<DataPacket>(newValue);
+         var notif = getRpcNotification(dp);
+         send([new(id, notif)]);
+      }
+
+      void Dispose() =>
+         stream.onChange -= OnChange;
+   }
+
+   void unsubscribe(WebsocketClientID id, JsonRpcRequest<JsonObject?> req) {
+      var subParams = req.Params!.Deserialize<SubscriptionParams>();
+      var subParamsStr = JsonSerializer.Serialize(subParams, serializerOpts);
+      // Minimize amount of code inside lock (just need it to find/remove the subscription)
+      List<ClientSubscription>? subs = null;
+      ClientSubscription? sub = null;
+      lock (lockObj) {
+         subs = clients.GetValueOrDefault(id);
+         subs?.TryRemoveFirst(s => s!.Params.Equals(subParams), out sub);
+      }
+      if (subs is null) {
+         // Didn't find client (log/throw).
+         var msg = $"Unable to unsubscribe: did not find client. Id: {id}.\nParams:\n{subParamsStr}";
+         Log.Api.error(msg);
+         throw new Exception(msg);
+      }
+      if (sub is null) {
+         // Found client, but didn't find subscription (log/throw).
+         var msg = $"Unable to unsubscribe: did not find the specified subscription. " +
+            $"Id: {id}. Request:\n{subParams}";
+         Log.Api.error(msg);
+         throw new Exception(msg);
+      }
+      // Found client and subscription (dispose/remove subscription).
+      Log.Api.info($"Unsubscribing client. Id: {id}.\nParams:\n{subParamsStr}");
+      sub.Dispose();
+   }
+
+   void unsubscribeAll(WebsocketClientID id) {
+      lock (lockObj) {
+         if (!clients.TryGetValue(id, out var subs)) {
+            throw new Exception(
+               $"Unable to unsubscribe: did not find client with id {id}");
+         }
+         subs.DisposeAll();
+         subs.Clear();
+      }
+   }
+
+   void onBadRequest(WebsocketIncomingMessage req, string? errorMsg) {
+      var rpcId = extractRpcId(req.message_body);
+      var logMsg = $"Recieved invalid request:\n{req.message_body}";
+      if (errorMsg is not null) {
+         logMsg += $"\n\n**Exception**\n{errorMsg}";
+      }
+      Log.Api.error(logMsg);
+      if (rpcId is null) {
+         return;
+      }
+      // Send error back to client
+      var rpcErr = JsonRpcError.Create(
+         (long)JsonRpcErrorCode.InvalidRequest,
+         $"Received invalid request: {errorMsg ?? "unknown error"}",
+         req.message_body);
+      sendError(req.sender_client_id, rpcId.Value, rpcErr);
+   }
+}

src/DataStreamSuite/Bts.DataStream.Websocket/MultilineStringJsonConverter.cs

@@ -1,48 +1,48 @@
-namespace Bts.DataStream.Websocket;
-
-using Spark.Core;
-
-using System;
-using System.Text.Json;
-using System.Text.Json.Serialization;
-
-class MultilineStringJsonConverter : JsonConverter<string> {
-   public override string? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
-      if (typeToConvert != typeof(string)) {
-         throw new ArgumentException($"Unable to parse {typeToConvert}", nameof(typeToConvert));
-      }
-      return reader.TokenType switch {
-         JsonTokenType.String => stringImpl(ref reader),
-         JsonTokenType.StartArray => arrayImpl(ref reader),
-         _ => throw new ArgumentException(
-            $"Unable to parse {typeof(SubscriptionParams)} from {reader.TokenType}"),
-      };
-
-      static string? stringImpl(ref Utf8JsonReader reader) =>
-         new(reader.GetString()!);
-
-      static string? arrayImpl(ref Utf8JsonReader reader) {
-         var lines = new List<string>(2);
-         while (reader.Read()) {
-            switch (reader.TokenType) {
-               case JsonTokenType.String:
-                  lines.Add(reader.GetString()!);
-                  break;
-               case JsonTokenType.EndArray:
-                  return string.Join("\n", lines);
-            }
-         }
-         throw new JsonException(
-            $"Failed to parse {typeof(SubscriptionParams)} (did not reach end of array)");
-      }
-   }
-
-   public override void Write(Utf8JsonWriter writer, string value, JsonSerializerOptions options) {
-      var lines = value.Split("\n");
-      if (lines.Length < 2) {
-         writer.WriteRawValue(value);
-         return;
-      }
-      writer.WriteRawValue($"[{", ".join(lines)}]");
-   }
-}
+namespace Bts.DataStream.Websocket;
+
+using Spark.Core;
+
+using System;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+class MultilineStringJsonConverter : JsonConverter<string> {
+   public override string? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+      if (typeToConvert != typeof(string)) {
+         throw new ArgumentException($"Unable to parse {typeToConvert}", nameof(typeToConvert));
+      }
+      return reader.TokenType switch {
+         JsonTokenType.String => StringImpl(ref reader),
+         JsonTokenType.StartArray => ArrayImpl(ref reader),
+         _ => throw new ArgumentException(
+            $"Unable to parse {typeof(SubscriptionParams)} from {reader.TokenType}"),
+      };
+
+      static string? StringImpl(ref Utf8JsonReader reader) =>
+         new(reader.GetString()!);
+
+      static string? ArrayImpl(ref Utf8JsonReader reader) {
+         var lines = new List<string>(2);
+         while (reader.Read()) {
+            switch (reader.TokenType) {
+               case JsonTokenType.String:
+                  lines.Add(reader.GetString()!);
+                  break;
+               case JsonTokenType.EndArray:
+                  return string.Join("\n", lines);
+            }
+         }
+         throw new JsonException(
+            $"Failed to parse {typeof(SubscriptionParams)} (did not reach end of array)");
+      }
+   }
+
+   public override void Write(Utf8JsonWriter writer, string value, JsonSerializerOptions options) {
+      var lines = value.Split("\n");
+      if (lines.Length < 2) {
+         writer.WriteRawValue(value);
+         return;
+      }
+      writer.WriteRawValue($"[{", ".join(lines)}]");
+   }
+}

src/DataStreamSuite/Bts.DataStream.Websocket/Session.cs

@@ -1,27 +1,27 @@
-namespace Bts.DataStream.Websocket;
-
-using bts;
-using bts.api.core;
-
-using Bts.Websocket;
-
-using Google.Protobuf;
-
-using System.Text.Json;
-
-public static class Session {
-   static int sessionIdCounter;
-
-   public static async Task Start(
-      ServiceContext context, WebsocketServerConfig config, JsonSerializerOptions? opts) {
-      opts ??= JsonSerializerOptions.Default;
-      var sessionId = Interlocked.Increment(ref sessionIdCounter);
-      var gateway = new WebsocketGatewayObservable(config);
-      var sync = new DataSync(context, opts);
-      using var syncSub = gateway.Subscribe(sync);
-      using var gwSub = sync.Subscribe(gateway);
-      Log.Api.info($"Starting DataStream Websocket Session {sessionId}");
-      Log.Api.info($"DataStream Websocket Session {sessionId} config:\n{JsonFormatter.Default.Format(config)}");
-      await gateway.ConnectAsync();
-   }
-}
+namespace Bts.DataStream.Websocket;
+
+using bts;
+
+using Bts.Websocket;
+
+using Google.Protobuf;
+
+using System.Text.Json;
+
+public static class Session {
+   static int sessionIdCounter;
+
+   public static async Task Start(
+      WebsocketServerConfig config, JsonSerializerOptions? opts) {
+      opts ??= JsonSerializerOptions.Default;
+      var sessionId = Interlocked.Increment(ref sessionIdCounter);
+      var gateway = new WebsocketGatewayObservable(config);
+      var sync = new DataSync(opts);
+      using (gateway.Subscribe(sync))
+      using (sync.Subscribe(gateway)) {
+         Log.Api.info($"Starting DataStream Websocket Session {sessionId}");
+         Log.Api.info($"DataStream Websocket Session {sessionId} config:\n{JsonFormatter.Default.Format(config)}");
+         await gateway.ConnectAsync();
+      }
+   }
+}

src/DataStreamSuite/Bts.DataStream.Websocket/SubscriptionParams.cs

@@ -1,110 +1,110 @@
-namespace Bts.DataStream.Websocket;
-
-using Spark.Core;
-
-using System;
-using System.Diagnostics.CodeAnalysis;
-using System.Text.Json;
-using System.Text.Json.Serialization;
-
-public class SubscriptionParams : IEquatable<SubscriptionParams> {
-   static class PropNames {
-      public const string QUERY = "query";
-   }
-
-   public SubscriptionParams(string? query) {
-      Query = query;
-   }
-
-   // Serializer supports plain string, or an array of lines for convenience
-   [MaybeNull]
-   [JsonPropertyName(PropNames.QUERY)]
-   [JsonConverter(typeof(MultilineStringJsonConverter))]
-   public string? Query { get; set; }
-
-   public bool Equals(SubscriptionParams? other) =>
-      other is not null &&
-      Query == other.Query;
-
-   class SubscriptionParamsConverter : JsonConverter<SubscriptionParams> {
-      public override bool CanConvert(Type typeToConvert) =>
-         typeToConvert == typeof(SubscriptionParams);
-
-      public override SubscriptionParams Read(
-         ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
-         if (typeToConvert != typeof(SubscriptionParams)) {
-            throw new ArgumentException($"Unable to parse {typeToConvert}", nameof(typeToConvert));
-         }
-         return read(ref reader);
-      }
-
-      SubscriptionParams read(ref Utf8JsonReader reader) {
-         return reader.TokenType switch {
-            JsonTokenType.String => stringImpl(ref reader),
-            JsonTokenType.StartArray => arrayImpl(ref reader),
-            JsonTokenType.StartObject => objectImpl(ref reader),
-            _ => throw new ArgumentException(
-               $"Unable to parse {typeof(SubscriptionParams)} from {reader.TokenType}"),
-         };
-
-         static SubscriptionParams stringImpl(ref Utf8JsonReader reader) =>
-            new(reader.GetString()!);
-
-         static SubscriptionParams arrayImpl(ref Utf8JsonReader reader) {
-            var lines = new List<string>(2);
-            while (reader.Read()) {
-               switch (reader.TokenType) {
-                  case JsonTokenType.String:
-                     lines.Add(reader.GetString()!);
-                     break;
-                  case JsonTokenType.EndArray:
-                     return new("\n".join(lines));
-               }
-            }
-            throw new JsonException(
-               $"Failed to parse {typeof(SubscriptionParams)} (did not reach end of array)");
-         }
-
-         static SubscriptionParams objectImpl(ref Utf8JsonReader reader) {
-            var lines = new List<string>(2);
-            while (reader.Read()) {
-               switch (reader.TokenType) {
-                  case JsonTokenType.PropertyName:
-                     var propName = reader.GetString()!;
-                     if (propName == PropNames.QUERY) {
-                        switch (reader.TokenType) {
-                           case JsonTokenType.StartArray:
-                              return arrayImpl(ref reader);
-                           case JsonTokenType.String:
-                              return stringImpl(ref reader);
-                        }
-                     }
-                     break;
-                  case JsonTokenType.String:
-                     lines.Add(reader.GetString()!);
-                     break;
-                  case JsonTokenType.EndArray:
-                     return new("\n".join(lines));
-               }
-            }
-            throw new JsonException(
-               $"Failed to parse {typeof(SubscriptionParams)} (did not reach end of array)");
-         }
-      }
-
-      public override void Write(
-         Utf8JsonWriter writer, SubscriptionParams value, JsonSerializerOptions options) {
-         var q = value.Query;
-         var lines = q?.Split("\n");
-         if (lines is null || lines.Length < 2) {
-            writer.WriteString(PropNames.QUERY, value.Query);
-            return;
-         }
-         writer.WriteStartArray(PropNames.QUERY);
-         foreach (var l in lines) {
-            writer.WriteStringValue(l);
-         }
-         writer.WriteEndArray();
-      }
-   }
-}
+namespace Bts.DataStream.Websocket;
+
+using Spark.Core;
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+public class SubscriptionParams : IEquatable<SubscriptionParams> {
+   static class PropNames {
+      public const string QUERY = "query";
+   }
+
+   public SubscriptionParams(string? query) {
+      Query = query;
+   }
+
+   // Serializer supports plain string, or an array of lines for convenience
+   [MaybeNull]
+   [JsonPropertyName(PropNames.QUERY)]
+   [JsonConverter(typeof(MultilineStringJsonConverter))]
+   public string? Query { get; set; }
+
+   public bool Equals(SubscriptionParams? other) =>
+      other is not null &&
+      Query == other.Query;
+
+   class SubscriptionParamsConverter : JsonConverter<SubscriptionParams> {
+      public override bool CanConvert(Type typeToConvert) =>
+         typeToConvert == typeof(SubscriptionParams);
+
+      public override SubscriptionParams Read(
+         ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+         if (typeToConvert != typeof(SubscriptionParams)) {
+            throw new ArgumentException($"Unable to parse {typeToConvert}", nameof(typeToConvert));
+         }
+         return read(ref reader);
+      }
+
+      SubscriptionParams read(ref Utf8JsonReader reader) {
+         return reader.TokenType switch {
+            JsonTokenType.String => stringImpl(ref reader),
+            JsonTokenType.StartArray => arrayImpl(ref reader),
+            JsonTokenType.StartObject => objectImpl(ref reader),
+            _ => throw new ArgumentException(
+               $"Unable to parse {typeof(SubscriptionParams)} from {reader.TokenType}"),
+         };
+
+         static SubscriptionParams stringImpl(ref Utf8JsonReader reader) =>
+            new(reader.GetString()!);
+
+         static SubscriptionParams arrayImpl(ref Utf8JsonReader reader) {
+            var lines = new List<string>(2);
+            while (reader.Read()) {
+               switch (reader.TokenType) {
+                  case JsonTokenType.String:
+                     lines.Add(reader.GetString()!);
+                     break;
+                  case JsonTokenType.EndArray:
+                     return new("\n".join(lines));
+               }
+            }
+            throw new JsonException(
+               $"Failed to parse {typeof(SubscriptionParams)} (did not reach end of array)");
+         }
+
+         static SubscriptionParams objectImpl(ref Utf8JsonReader reader) {
+            var lines = new List<string>(2);
+            while (reader.Read()) {
+               switch (reader.TokenType) {
+                  case JsonTokenType.PropertyName:
+                     var propName = reader.GetString()!;
+                     if (propName == PropNames.QUERY) {
+                        switch (reader.TokenType) {
+                           case JsonTokenType.StartArray:
+                              return arrayImpl(ref reader);
+                           case JsonTokenType.String:
+                              return stringImpl(ref reader);
+                        }
+                     }
+                     break;
+                  case JsonTokenType.String:
+                     lines.Add(reader.GetString()!);
+                     break;
+                  case JsonTokenType.EndArray:
+                     return new("\n".join(lines));
+               }
+            }
+            throw new JsonException(
+               $"Failed to parse {typeof(SubscriptionParams)} (did not reach end of array)");
+         }
+      }
+
+      public override void Write(
+         Utf8JsonWriter writer, SubscriptionParams value, JsonSerializerOptions options) {
+         var q = value.Query;
+         var lines = q?.Split("\n");
+         if (lines is null || lines.Length < 2) {
+            writer.WriteString(PropNames.QUERY, value.Query);
+            return;
+         }
+         writer.WriteStartArray(PropNames.QUERY);
+         foreach (var l in lines) {
+            writer.WriteStringValue(l);
+         }
+         writer.WriteEndArray();
+      }
+   }
+}

src/DataStreamSuite/Bts.DataStream.WebsocketClient/Bts.DataStream.WebsocketClient.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk.Web">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <Nullable>enable</Nullable>
     <ImplicitUsings>enable</ImplicitUsings>
     <EnableDefaultContentItems>True</EnableDefaultContentItems>

src/DataStreamSuite/Bts.DataStream.WebsocketServer/Bts.DataStream.WebsocketServer.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>

src/DataStreamSuite/Bts.DataStream.WebsocketServer/Program.cs

@@ -39,7 +39,7 @@ static async Task run(
    Console.WriteLine("Starting DataStreamWebsocketServer...");
    var serviceCtx = ServiceContext.create(sparkdConfigSource);
    await serviceCtx.login(user, password);
-   await Session.Start(serviceCtx, wssConfig, opts);
+   await Session.Start(wssConfig, opts);
    // if (sparkdConfigSource is not null && sparkdConfigSource.Length > 9999) {
    // } else {
    //    await ChatGptSession.Start();

src/DataStreamSuite/Bts.DataStreamWebApp.Client/package-lock.json

@@ -9,7 +9,8 @@
       "version": "0.0.0",
       "dependencies": {
         "react": "^18.2.0",
-        "react-dom": "^18.2.0"
+        "react-dom": "^18.2.0",
+        "react-use-websocket": "^4.5.0"
       },
       "devDependencies": {
         "@types/react": "^18.2.43",
@@ -3325,6 +3326,15 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/react-use-websocket": {
+      "version": "4.5.0",
+      "resolved": "https://registry.npmjs.org/react-use-websocket/-/react-use-websocket-4.5.0.tgz",
+      "integrity": "sha512-oxYVLWM3Lv0InCfjW7hG/Hk0hkE0P1SiLd5/I3d5x0W4riAnDUkD4VEu7qNVAqxNjBF3nU7k0jLMOetLXpwfsA==",
+      "peerDependencies": {
+        "react": ">= 18.0.0",
+        "react-dom": ">= 18.0.0"
+      }
+    },
     "node_modules/reflect.getprototypeof": {
       "version": "1.0.4",
       "resolved": "https://registry.npmjs.org/reflect.getprototypeof/-/reflect.getprototypeof-1.0.4.tgz",

src/DataStreamSuite/Bts.DataStreamWebApp.Client/package.json

@@ -11,7 +11,8 @@
   },
   "dependencies": {
     "react": "^18.2.0",
-    "react-dom": "^18.2.0"
+    "react-dom": "^18.2.0",
+    "react-use-websocket": "^4.5.0"
   },
   "devDependencies": {
     "@types/react": "^18.2.43",

src/DataStreamSuite/Bts.DataStreamWebApp.Client/src/App.css

@@ -21,3 +21,24 @@ th, td {
     background-color: var(--cell-background-color);
     color: var(--cell-color);
 }
+
+textarea#query-input {
+  height: 5em;
+  width: 50em;
+}
+
+button#query-button {
+  height: 5em;
+  vertical-align: top;
+}
+
+table#query-output {
+  float: none;
+  clear: both;
+}
+
+p#footer {
+  float: none;
+  clear: both;
+  vertical-align: bottom;
+}

src/DataStreamSuite/Bts.DataStreamWebApp.Client/src/App.jsx

@@ -1,75 +1,28 @@
-import { useEffect, useState, Component } from 'react';
-import './App.css';
-
-function App() {
-    const [forecasts, setForecasts] = useState();
-
-    useEffect(() => {
-        populateWeatherData();
-    }, []);
-
-    const contents = forecasts === undefined
-        ? <p><em>Loading... Please refresh once the ASP.NET backend has started. See <a href="https://aka.ms/jspsintegrationreact">https://aka.ms/jspsintegrationreact</a> for more details.</em></p>
-        : <table className="table table-striped" aria-labelledby="tabelLabel">
-            <thead>
-                <tr>
-                    <th>Date</th>
-                    <th>Temp. (C)</th>
-                    <th>Temp. (F)</th>
-                    <th>Summary</th>
-                </tr>
-            </thead>
-            <tbody>
-                {forecasts.map(forecast =>
-                    <tr key={forecast.date}>
-                        <td>{forecast.date}</td>
-                        <td>{forecast.temperatureC}</td>
-                        <td>{forecast.temperatureF}</td>
-                        <td>{forecast.summary}</td>
-                    </tr>
-                )}
-            </tbody>
-        </table>;
-
-    return (
-        <div>
-            <h1 id="tabelLabel">Weather forecast</h1>
-            <p>This component demonstrates fetching data from the server.</p>
-            {contents}
-        </div>
-    );
-    
-    async function populateWeatherData() {
-        const response = await fetch('weatherforecast');
-        const data = await response.json();
-        setForecasts(data);
-    }
-}
-
-export default App;
+import { useEffect, useState, Component } from "react";
+import { useWebSocket } from "react-use-websocket";
+import "./App.css";
 
 export class Home extends Component {
   static displayName = Home.name;
   // static sparkdHost = '192.168.50.94';
-  static sparkdHost = 'localhost';
+  static sparkdHost = "localhost";
 
   // static websocket_url = 'wss://markets.api.uat.cmegroup.com/marketdatastream/v1';
   // static access_token = 'eyJhbGciOiJSUzI1NiIsImtpZCI6IjF0al9MTVFrT2pGVzJWQTZvdkZzOEZHUWViMCIsInBpLmF0bSI6IjEifQ.eyJzY29wZSI6W10sImNsaWVudF9pZCI6ImFwaV90aGlua2FscGhhMzIxIiwiYXVkIjoiTnIiLCJqdGkiOiIweERtb3NnU2NHcE5GUEFaIiwic3ViIjoiYXBpX3RoaW5rYWxwaGEzMjEiLCJleHAiOjE2OTgzNTY5OTJ9.uJJEhWpujGiyJ5_lypiIPB8xR0GkuXqydtCugp5xD0hyTuX6VkQdNoY_oaRXXGRCUPCvfsXpU-HfL7pRkcXCjMLTrVIqf3RjD4_gar_ExbIb180nbYMG87E4rOILi5bIin51KOcMNBdHW7pTKwsS221XGyIAKIj65WxD-K8QSVr1HN6s7KDfYdez5dstWWC6xGg_3IZkrJjx8Df1HNT73K9PwUaAl7gcK4_2RSr8L636QbF3_y4Tv26g5IEv90Mc1mnAFPvUGI-nDR4s5Vso0398DlYl_tw-zbQQmn-QuQ6rS_ZIcZKgyoHKwD-3lgV-J1_--ndHdh8qwJC7Hk8ZKg'
 
   render() {
     let socket = null;
-
+    const wsUrl = `ws://localhost:5268/ws`;
     function connectToSparkd() {
-      const wsUrl = `ws://${Home.sparkdHost}:8080`;
       // const wsUrl = Home.websocket_url;
       if (socket == null) {
-        socket = new WebSocket(wsUrl)
+        socket = new WebSocket(wsUrl);
       }
       if (socket && socket.readyState === WebSocket.OPEN) {
         return;
       }
 
-      const output = document.getElementById('query-output');
+      const output = document.getElementById("query-output");
       socket.onopen = (event) => {
         console.log(`Connected to ${wsUrl}`);
       };
@@ -99,31 +52,16 @@ export class Home extends Component {
         connectToSparkd();
       }
       if (socket == null || !socket) {
-        console.log('Failed to connect to websocket server');
+        console.log("Failed to connect to websocket server");
         return;
       }
       if (socket.readyState === WebSocket.OPEN) {
-        const queryInput = document.getElementById('query-input');
-        // const req = {
-        //   header: {
-        //     messageType: "subscribe",
-        //     sentTime: "",
-        //     version: "",
-        //     requestId: "1",
-        //     token: ""
-        //   },
-        //   payload: {
-        //     subscriptionMessageTypes: ["TRD"],
-        //     subscriptions: [{
-        //       exchangeMic: "XCME", productType: "FUT", productCode: "BTC"
-        //     }]
-        //   }
-        // };
+        const queryInput = document.getElementById("query-input");
         const rpcReq = {
-          jsonrpc: '2.0',
-          method: 'subscribe',
+          jsonrpc: "2.0",
+          method: "subscribe",
           params: {
-            query: queryInput.value
+            query: queryInput.value,
           },
           id: 1,
         };
@@ -136,19 +74,19 @@ export class Home extends Component {
         <h1>Data Stream Query Analyzer</h1>
         <p>Run queries against the BTS Cloud</p>
         <div>
-          <textarea id="query-input" placeholder='Enter Query'></textarea>
+          <textarea id="query-input" placeholder="Enter Query"></textarea>
+          <button id="query-button" onClick={executeQuery}>
+            Execute
+          </button>
         </div>
-        <div>
-          <button id="query-button" onClick={executeQuery}>Execute</button>
-        </div>
-        <table id="query-output">
-        </table>
-        <ul>
-          <li><strong>Client-side navigation</strong>. For example, click <em>Counter</em> then <em>Back</em> to return here.</li>
-          <li><strong>Development server integration</strong>. In development mode, the development server from <code>create-react-app</code> runs in the background automatically, so your client-side resources are dynamically built on demand and the page refreshes when you modify any file.</li>
-          <li><strong>Efficient production builds</strong>. In production mode, development-time features are disabled, and your <code>dotnet publish</code> configuration produces minified, efficiently bundled JavaScript files.</li>
-        </ul>
-        <p>The <code>ClientApp</code> subdirectory is a standard React application based on the <code>create-react-app</code> template. If you open a command prompt in that directory, you can run <code>npm</code> commands such as <code>npm test</code> or <code>npm install</code>.</p>
+        <table id="query-output"></table>
+        <p id="footer">
+          The <code>ClientApp</code> subdirectory is a standard React
+          application based on the <code>create-react-app</code> template. If
+          you open a command prompt in that directory, you can run{" "}
+          <code>npm</code> commands such as <code>npm test</code> or{" "}
+          <code>npm install</code>.
+        </p>
       </div>
     );
   }

src/DataStreamSuite/Bts.DataStreamWebApp.Client/src/main.jsx

@@ -1,10 +1,10 @@
 import React from 'react'
 import ReactDOM from 'react-dom/client'
-import App from './App.jsx'
+import {Home} from './App.jsx'
 import './index.css'
 
 ReactDOM.createRoot(document.getElementById('root')).render(
   <React.StrictMode>
-    <App />
+    <Home />
   </React.StrictMode>,
 )

src/DataStreamSuite/Bts.DataStreamWebApp.Server/Bts.DataStreamWebApp.Server.csproj

@@ -11,9 +11,11 @@
   </PropertyGroup>
 
   <ItemGroup>
+    <PackageReference Include="CommandLineParser" Version="2.9.1" />
     <PackageReference Include="Microsoft.AspNetCore.SpaProxy">
       <Version>8.*-*</Version>
     </PackageReference>
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
     <PackageReference Include="Swashbuckle.AspNetCore" Version="6.4.0" />
   </ItemGroup>
 
@@ -23,6 +25,11 @@
     </ProjectReference>
     <ProjectReference Include="..\DataStream\DataStream.csproj" />
     <ProjectReference Include="..\SharedStreams\SharedStreams.csproj" />
+    <ProjectReference Include="..\..\client\spark_api\spark_api.csproj" />
+    <ProjectReference Include="..\..\client\spark_websocket\spark_websocket.csproj" />
   </ItemGroup>
 
+  <!-- <ItemGroup>
+    <Content Update="wwwroot\alt-index.html" CopyToPublishDirectory="Never" />
+  </ItemGroup> -->
 </Project>

src/DataStreamSuite/Bts.DataStreamWebApp.Server/Controllers/DataStreamSubscriptionController.cs

@@ -1,25 +1,117 @@
 namespace Bts.DataStreamWebApp.Server.Controllers;
+
+using BCG;
+
+using bts.api.core;
+
+using Bts.DataStreamExpressions;
+
 using Microsoft.AspNetCore.Mvc;
 
-[ApiController]
-[Route("[controller]")]
-public class DataStreamSubscriptionController : ControllerBase {
-   private static readonly string[] Summaries = new[]
-   {
-        "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
-    };
+using Spark.Core.Disposables;
 
-   private readonly ILogger<DataStreamSubscriptionController> _logger;
+using System.Net.WebSockets;
+using System.Text;
+using System.Text.Json;
 
-   public DataStreamSubscriptionController(ILogger<DataStreamSubscriptionController> logger) {
-      _logger = logger;
+// [Route("[controller]")]
+[Route("/ws")]
+public class DataStreamSubscriptionController(ILogger<DataStreamSubscriptionController> logger) : ControllerBase {
+   readonly ILogger<DataStreamSubscriptionController> _logger = logger;
+   IDisposable? streamSubscription;
+
+   [Route("/ws")]
+   public async Task Get() {
+      if (!HttpContext.WebSockets.IsWebSocketRequest) {
+         _logger.LogError("Expected websocket request on path '{}'", HttpContext.Request.Path);
+         return;
+      }
+      Console.WriteLine("Establishing websocket connection...");
+      using var webSocket = await HttpContext.WebSockets.AcceptWebSocketAsync();
+      Console.WriteLine($"Websocket connection established.");
+      await runWebSocketServer(null, "bts", string.Empty, webSocket);
    }
 
-   [HttpGet(Name = "GetDataStreamSubscription")]
-   public IEnumerable<DataStreamSubscription> Get() {
-      return Enumerable.Range(1, 5).Select(index => new DataStreamSubscription {
-         Query = "fake queronious"
-      })
-      .ToArray();
+   public static async Task Echo(WebSocket webSocket) {
+      var buffer = new byte[1024 * 4];
+      var receiveResult = await webSocket.ReceiveAsync(
+          new ArraySegment<byte>(buffer), CancellationToken.None);
+
+      while (!receiveResult.CloseStatus.HasValue) {
+         await webSocket.SendAsync(
+             new ArraySegment<byte>(buffer, 0, receiveResult.Count),
+             receiveResult.MessageType,
+             receiveResult.EndOfMessage,
+             CancellationToken.None);
+
+         receiveResult = await webSocket.ReceiveAsync(
+             new ArraySegment<byte>(buffer), CancellationToken.None);
+      }
+
+      await webSocket.CloseAsync(
+          receiveResult.CloseStatus.Value,
+          receiveResult.CloseStatusDescription,
+          CancellationToken.None);
+   }
+
+   async Task<int> runWebSocketServer(string? sparkd, string user, string password, WebSocket webSocket) {
+      var context = ServiceContext.create(sparkd);
+      await context.login(user, password);
+      var buffer = new byte[1024 * 4];
+      var receiveResult = await webSocket.ReceiveAsync(
+          new ArraySegment<byte>(buffer), CancellationToken.None);
+
+      try {
+         while (!receiveResult.CloseStatus.HasValue) {
+            receiveResult = await webSocket.ReceiveAsync(
+                new ArraySegment<byte>(buffer), CancellationToken.None);
+            var msg = Encoding.UTF8.GetString(buffer, 0, receiveResult.Count);
+            // var queryArgs = new QueryArguments { Query = msg };
+            var rpcReq = JsonSerializer.Deserialize<Bts.Websocket.JsonRpcRequest<DataStreamSubscription>>(msg);
+            var queryArgs = rpcReq!.Params;
+            // if (queryArgs is null) {
+            //    Console.WriteLine("Invalid queryArgs.");
+            //    continue;
+            // }
+            var exp = DataStreamExpressionsInterpreter.Evaluate(queryArgs.Query!);
+            if (exp is null) {
+               Console.WriteLine($"Invalid query expression: {queryArgs.Query}.");
+               continue;
+            }
+            var vs = exp.getView(new Dictionary<string, StatementExpression>(0));
+            Disposable.dispose(ref streamSubscription);
+            vs.onChange += onStreamChanged;
+            streamSubscription = Disposable.Create(() => vs.onChange -= onStreamChanged);
+            // await webSocket.SendAsync(
+            //     new ArraySegment<byte>(buffer, 0, receiveResult.Count),
+            //     receiveResult.MessageType,
+            //     receiveResult.EndOfMessage,
+            //     CancellationToken.None);
+         }
+      } catch (Exception ex) {
+         Console.WriteLine($"Exception on WebsocketServer thread: {ex}");
+         return 1;
+      }
+
+      return 0;
+
+      async void onStreamChanged(object newValue) {
+         if (newValue is not DataPacket dp) {
+            Console.WriteLine(
+               $"OnStreamChanged delegate expected DataPacket (actually received {newValue?.GetType()}.");
+            return;
+         }
+         Console.WriteLine("Received stream update.");
+         var added_rows_str = dp.addedRows.get_printed_rows(val => val.Length);
+         var msg = $"Received new rows:\n{added_rows_str}";
+         // var payload = new ReadOnlyMemory<byte>([.. msg]);
+         var encoded = Encoding.UTF8.GetBytes(msg);
+         var payload = new ArraySegment<byte>(encoded, 0, encoded.Length);
+         await webSocket.SendAsync(
+             payload,
+             receiveResult.MessageType,
+             receiveResult.EndOfMessage,
+             CancellationToken.None);
+      }
    }
 }

src/DataStreamSuite/Bts.DataStreamWebApp.Server/Controllers/WeatherForecastController.cs

@@ -3,25 +3,16 @@ using Microsoft.AspNetCore.Mvc;
 
 [ApiController]
 [Route("[controller]")]
-public class WeatherForecastController : ControllerBase
-{
-   private static readonly string[] Summaries = new[]
-   {
-        "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
-    };
+public class WeatherForecastController(ILogger<WeatherForecastController> logger) : ControllerBase {
+   static readonly string[] Summaries = [
+      "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
+   ];
 
-   private readonly ILogger<WeatherForecastController> _logger;
-
-   public WeatherForecastController(ILogger<WeatherForecastController> logger)
-   {
-      _logger = logger;
-   }
+   readonly ILogger<WeatherForecastController> _logger = logger;
 
    [HttpGet(Name = "GetWeatherForecast")]
-   public IEnumerable<WeatherForecast> Get()
-   {
-      return Enumerable.Range(1, 5).Select(index => new WeatherForecast
-      {
+   public IEnumerable<WeatherForecast> Get() {
+      return Enumerable.Range(1, 5).Select(index => new WeatherForecast {
          Date = DateOnly.FromDateTime(DateTime.Now.AddDays(index)),
          TemperatureC = Random.Shared.Next(-20, 55),
          Summary = Summaries[Random.Shared.Next(Summaries.Length)]

src/DataStreamSuite/Bts.DataStreamWebApp.Server/DataStreamSubscription.cs

@@ -1,5 +1,8 @@
 namespace Bts.DataStreamWebApp.Server;
 
+using System.Text.Json.Serialization;
+
 public class DataStreamSubscription {
+   [JsonPropertyName("query")]
    public string? Query { get; set; }
 }

src/DataStreamSuite/Bts.DataStreamWebApp.Server/DataStreamUpdate.cs

@@ -0,0 +1,8 @@
+namespace Bts.DataStreamWebApp.Server;
+
+using BCG;
+
+class DataStreamUpdate {
+   public List<IBlueRow> addedRows { get; set; } = new(0);
+   public List<IBlueRow> deletedRows { get; set; } = new(0);
+}

src/DataStreamSuite/Bts.DataStreamWebApp.Server/DataStreamWebAppServerOptions.cs

@@ -0,0 +1,14 @@
+namespace Bts.DataStreamWebApp.Server;
+
+using CommandLine;
+
+class DataStreamWebAppServerOptions {
+   [Option("sparkd")]
+   public string? sparkd { get; set; }
+
+   [Option("user", Default = "bts")]
+   public string? user { get; set; }
+
+   [Option("password", Default = "")]
+   public string? password { get; set; }
+}

src/DataStreamSuite/Bts.DataStreamWebApp.Server/DataStreamWebsocketHandler.cs

@@ -0,0 +1,58 @@
+using Microsoft.AspNetCore.Http;
+using Microsoft.Extensions.Logging;
+
+using System;
+using System.Net.WebSockets;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Bts.DataStreamWebApp.Server {
+   // public class DataStreamWebSocketHandler {
+   //    readonly WebSocketConnectionManager _connectionManager = new();
+   //    readonly ILogger<DataStreamWebSocketHandler> _logger;
+
+   //    public DataStreamWebSocketHandler(
+   //       WebSocketConnectionManager connectionManager,
+   //       ILogger<DataStreamWebSocketHandler> logger
+   //    ) {
+   //       _connectionManager = connectionManager;
+   //       _logger = logger;
+   //    }
+
+   //    public async Task HandleWebSocket(HttpContext context, WebSocket webSocket) {
+   //       var socketId = _connectionManager.AddSocket(webSocket);
+
+   //       _logger.LogInformation($"WebSocket connection established with ID {socketId}");
+
+   //       while (webSocket.State == WebSocketState.Open) {
+   //          var message = await ReceiveMessageAsync(webSocket);
+   //          if (message != null) {
+   //             _logger.LogInformation($"Received message from ID {socketId}: {message}");
+   //             await BroadcastMessageAsync(message);
+   //          }
+   //       }
+
+   //       _connectionManager.RemoveSocket(socketId);
+   //       _logger.LogInformation($"WebSocket connection closed with ID {socketId}");
+   //    }
+
+   //    async Task<string?> ReceiveMessageAsync(WebSocket webSocket) {
+   //       var buffer = new byte[1024];
+   //       var result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);
+
+   //       if (result.CloseStatus.HasValue) {
+   //          return null;
+   //       }
+
+   //       return System.Text.Encoding.UTF8.GetString(buffer, 0, result.Count);
+   //    }
+
+   //    async Task BroadcastMessageAsync(string message) {
+   //       foreach (var socket in _connectionManager.GetAllSockets()) {
+   //          if (socket.Value.State == WebSocketState.Open) {
+   //             await socket.Value.SendAsync(System.Text.Encoding.UTF8.GetBytes(message), WebSocketMessageType.Text, true, CancellationToken.None);
+   //          }
+   //       }
+   //    }
+   // }
+}

src/DataStreamSuite/Bts.DataStreamWebApp.Server/Program.cs

@@ -1,30 +1,166 @@
-var builder = WebApplication.CreateBuilder(args);
+using BCG;
 
-// Add services to the container.
+using bts;
+using bts.api.core;
+using bts.utils;
 
-builder.Services.AddControllers();
-// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
-builder.Services.AddEndpointsApiExplorer();
-builder.Services.AddSwaggerGen();
+using Bts.DataStreamExpressions;
+using Bts.DataStreamWebApp.Server;
+using Bts.DataStreamWebApp.Server.Controllers;
 
-var app = builder.Build();
+using CommandLine;
 
-app.UseDefaultFiles();
-app.UseStaticFiles();
+using mbts.config;
 
-// Configure the HTTP request pipeline.
-if (app.Environment.IsDevelopment())
-{
-   app.UseSwagger();
-   app.UseSwaggerUI();
+using System.Net.WebSockets;
+using System.Reactive.Disposables;
+using System.Reactive.Linq;
+using System.Text;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+static string fmtReq(HttpRequest req) =>
+   $"{req.Protocol}://{req.Host}/{req.Path}?{req.QueryString}";
+
+static string fmtDataPacket(DataPacket dp) {
+   var sb = new StringBuilder();
+   var rows = dp.addedRows.Cast<IBlueRow>().ToList();
+   var colWidths = dp.schema.columnInfo.Select(c => rows.Max(r => r[c.colNo]?.ToString()?.Length ?? 0)).ToArray();
+   foreach (IBlueRow r in dp.addedRows) {
+      for (int i = 0; i < colWidths.Length; i++) {
+         var str = r[i]?.ToString() ?? string.Empty;
+         if (i > 0) {
+            sb.Append(" | ");
+         }
+         sb.Append(str);
+         var width = colWidths[i];
+         if (str.Length < width) {
+            sb.Append(new string(' ', width - str.Length));
+         }
+      }
+      sb.AppendLine();
+   }
+   return sb.ToString();
+   // var upd = new DataStreamUpdate();
+   // upd.addedRows.AddRange(dp.addedRows.Cast<IBlueRow>());
+   // upd.deletedRows.AddRange(dp.deletedRows.Cast<IBlueRow>());
+   // return fmtDataStreamUpdate(upd);
 }
 
-app.UseHttpsRedirection();
+static string fmtDataStreamUpdate(DataStreamUpdate rows) {
+   return JsonSerializer.Serialize(rows);
+}
 
-app.UseAuthorization();
+var parser = new Parser(ps => {
+   ps.CaseInsensitiveEnumValues = true;
+   ps.HelpWriter = Console.Out;
+});
 
-app.MapControllers();
+await parser.ParseArguments<DataStreamWebAppServerOptions>(args).
+   MapResult(run, errors => Task.FromResult(1));
 
-app.MapFallbackToFile("/index.html");
+async Task<int> run(DataStreamWebAppServerOptions opts) {
+   BTSNativeMethods.provide_command_line(args, args.Length);
+   Configuration.initialize();
+   var context = ServiceContext.create(opts.sparkd);
+   await context.login(opts.user!, opts.password!);
+   var vsWorkLoop = Observable.Interval(TimeSpan.FromMilliseconds(200)).Subscribe(_ => {
+      ViewStreamDatabase.instance.doWork();
+      MasterWorker.getInstance(false).doWork();
+   });
+   var builder = WebApplication.CreateBuilder(args);
+   builder.Services.AddDirectoryBrowser();
+   var app = builder.Build();
+   var wsOpts = new WebSocketOptions {
+      KeepAliveInterval = TimeSpan.FromMinutes(2)
+   };
+   app.UseWebSockets(wsOpts);
+   app.UseDefaultFiles();
+   app.UseStaticFiles();
+   app.MapFallbackToFile("/index.html");
 
-app.Run();
+   app.Use(async (context, next) => {
+      var reqDesc = fmtReq(context.Request);
+      Console.WriteLine($"Webserver received: {reqDesc}");
+      if (context.Request.Path == "/ws") {
+         if (context.WebSockets.IsWebSocketRequest) {
+            Console.WriteLine("Accepting websocket connection...");
+            using var webSocket = await context.WebSockets.AcceptWebSocketAsync();
+            Console.WriteLine("Websocket connection accepted.");
+            await runWebSocketServer(
+               opts.sparkd, opts.user!, opts.password!, webSocket);
+         } else {
+            context.Response.StatusCode = StatusCodes.Status400BadRequest;
+         }
+      } else {
+         Console.WriteLine($"Webserver ignoring req: {reqDesc}");
+         await next(context);
+      }
+   });
+
+   try {
+      await app.RunAsync();
+   } catch (Exception ex) {
+      Console.WriteLine($"Exception on DataStreamWebsocketServer thread: {ex}");
+      return 1;
+   }
+   Spark.Core.Disposables.Disposable.dispose(ref vsWorkLoop);
+   return 0;
+}
+
+async Task<int> runWebSocketServer(string? sparkd, string user, string password, WebSocket webSocket) {
+   var buffer = new byte[1024 * 4];
+   var receiveResult = await webSocket.ReceiveAsync(
+       new ArraySegment<byte>(buffer), CancellationToken.None);
+
+   try {
+      while (!receiveResult.CloseStatus.HasValue) {
+         Console.WriteLine("Awaiting websocket message from client");
+         receiveResult = await webSocket.ReceiveAsync(
+             new ArraySegment<byte>(buffer), CancellationToken.None);
+         var msg = Encoding.UTF8.GetString(buffer, 0, receiveResult.Count);
+         var rpcReq = JsonSerializer.Deserialize<Bts.Websocket.JsonRpcRequest<DataStreamSubscription>>(msg);
+         var queryArgs = rpcReq!.Params!;
+         // var queryArgs = new DataStreamSubscription { Query = msg };
+         var exp = DataStreamExpressionsInterpreter.Evaluate(queryArgs.Query!);
+         if (exp is null) {
+            Console.WriteLine($"Invalid query expression: {queryArgs.Query}.");
+            continue;
+         }
+         var vs = exp.getView(new Dictionary<string, StatementExpression>(0));
+         Console.WriteLine("Subscribing to stream...");
+         vs.onChange += onStreamChanged;
+
+         await webSocket.SendAsync(
+             new ArraySegment<byte>(buffer, 0, receiveResult.Count),
+             receiveResult.MessageType,
+             receiveResult.EndOfMessage,
+             CancellationToken.None);
+      }
+   } catch (Exception ex) {
+      Console.WriteLine($"Exception on WebsocketServer thread: {ex}");
+      return 1;
+   }
+
+   return 0;
+
+   async void onStreamChanged(object newValue) {
+      if (newValue is not DataPacket dp) {
+         Console.WriteLine(
+            $"OnStreamChanged delegate expected DataPacket (actually received {newValue?.GetType()}.");
+         return;
+      }
+      Console.WriteLine("Received stream update.");
+      var sb = new StringBuilder();
+      var updateDesc = fmtDataPacket(dp);
+      var msg = $"Received new rows:\n{updateDesc}";
+      // var payload = new ReadOnlyMemory<byte>([.. msg]);
+      var encoded = Encoding.UTF8.GetBytes(msg);
+      var payload = new ArraySegment<byte>(encoded, 0, encoded.Length);
+      await webSocket.SendAsync(
+          payload,
+          receiveResult.MessageType,
+          receiveResult.EndOfMessage,
+          CancellationToken.None);
+   }
+}

src/DataStreamSuite/Bts.DataStreamWebApp.Server/Properties/launchSettings.json

@@ -1,5 +1,10 @@
 {
   "profiles": {
+    "default": {
+      "commandName": "Project",
+      "launchBrowser": true,
+      "applicationUrl": "http://localhost:5400"
+    },
     "http": {
       "commandName": "Project",
       "launchBrowser": true,
@@ -40,4 +45,4 @@
       "sslPort": 44383
     }
   }
-}
+}

src/DataStreamSuite/Bts.DataStreamWebApp.Server/WebsocketConnectionManager.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Collections.Concurrent;
+using System.Net.WebSockets;
+
+namespace Bts.DataStreamWebApp.Server {
+   // public class WebSocketConnectionManager {
+   //    private readonly ConcurrentDictionary<Guid, WebSocket> _sockets = new ConcurrentDictionary<Guid, WebSocket>();
+
+   //    public Guid AddSocket(WebSocket socket) {
+   //       var socketId = Guid.NewGuid();
+   //       _sockets.TryAdd(socketId, socket);
+   //       return socketId;
+   //    }
+
+   //    public WebSocket? GetSocket(Guid socketId) {
+   //       _sockets.TryGetValue(socketId, out var socket);
+   //       return socket;
+   //    }
+
+   //    public ConcurrentDictionary<Guid, WebSocket>.ValueCollection GetAllSockets() {
+   //       return _sockets.Values;
+   //    }
+
+   //    public Guid? GetSocketId(WebSocket socket) {
+   //       foreach (var (key, value) in _sockets) {
+   //          if (value == socket) {
+   //             return key;
+   //          }
+   //       }
+   //       return null;
+   //    }
+
+   //    public void RemoveSocket(Guid socketId) {
+   //       _sockets.TryRemove(socketId, out _);
+   //    }
+   // }
+}

src/DataStreamSuite/Bts.DataStreamWebApp.Server/wwwroot/alt-index.html

@@ -0,0 +1,168 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8" />
+    <title></title>
+    <style>
+        table {
+            border: 0
+        }
+
+        .commslog-data {
+            font-family: Consolas, Courier New, Courier, monospace;
+        }
+
+        .commslog-server {
+            background-color: red;
+            color: white
+        }
+
+        .commslog-client {
+            background-color: green;
+            color: white
+        }
+    </style>
+</head>
+<body>
+    <h1>ALT WebSocket Sample Application</h1>
+    <p id="stateLabel">Ready to connect...</p>
+    <div>
+        <label for="connectionUrl">WebSocket Server URL:</label>
+        <input id="connectionUrl" />
+        <button id="connectButton" type="submit">Connect</button>
+    </div>
+    <p></p>
+    <div>
+        <label for="sendMessage">Message to send:</label>
+        <input id="sendMessage" disabled />
+        <button id="sendButton" type="submit" disabled>Send</button>
+        <button id="closeButton" disabled>Close Socket</button>
+    </div>
+
+    <h2>Communication Log</h2>
+    <table style="width: 800px">
+        <thead>
+            <tr>
+                <td style="width: 100px">From</td>
+                <td style="width: 100px">To</td>
+                <td>Data</td>
+            </tr>
+        </thead>
+        <tbody id="commsLog">
+        </tbody>
+    </table>
+
+    <script>
+        var connectionUrl = document.getElementById("connectionUrl");
+        var connectButton = document.getElementById("connectButton");
+        var stateLabel = document.getElementById("stateLabel");
+        var sendMessage = document.getElementById("sendMessage");
+        var sendButton = document.getElementById("sendButton");
+        var commsLog = document.getElementById("commsLog");
+        var closeButton = document.getElementById("closeButton");
+        var socket;
+
+        var scheme = document.location.protocol === "https:" ? "wss" : "ws";
+        var port = document.location.port ? (":" + document.location.port) : "";
+
+        connectionUrl.value = scheme + "://" + document.location.hostname + port + "/ws" ;
+
+        function updateState() {
+            function disable() {
+                sendMessage.disabled = true;
+                sendButton.disabled = true;
+                closeButton.disabled = true;
+            }
+            function enable() {
+                sendMessage.disabled = false;
+                sendButton.disabled = false;
+                closeButton.disabled = false;
+            }
+
+            connectionUrl.disabled = true;
+            connectButton.disabled = true;
+
+            if (!socket) {
+                disable();
+            } else {
+                switch (socket.readyState) {
+                    case WebSocket.CLOSED:
+                        stateLabel.innerHTML = "Closed";
+                        disable();
+                        connectionUrl.disabled = false;
+                        connectButton.disabled = false;
+                        break;
+                    case WebSocket.CLOSING:
+                        stateLabel.innerHTML = "Closing...";
+                        disable();
+                        break;
+                    case WebSocket.CONNECTING:
+                        stateLabel.innerHTML = "Connecting...";
+                        disable();
+                        break;
+                    case WebSocket.OPEN:
+                        stateLabel.innerHTML = "Open";
+                        enable();
+                        break;
+                    default:
+                        stateLabel.innerHTML = "Unknown WebSocket State: " + htmlEscape(socket.readyState);
+                        disable();
+                        break;
+                }
+            }
+        }
+
+        closeButton.onclick = function () {
+            if (!socket || socket.readyState !== WebSocket.OPEN) {
+                alert("socket not connected");
+            }
+            socket.close(1000, "Closing from client");
+        };
+
+        sendButton.onclick = function () {
+            if (!socket || socket.readyState !== WebSocket.OPEN) {
+                alert("socket not connected");
+            }
+            var data = sendMessage.value;
+            socket.send(data);
+            commsLog.innerHTML += '<tr>' +
+                '<td class="commslog-client">Client</td>' +
+                '<td class="commslog-server">Server</td>' +
+                '<td class="commslog-data">' + htmlEscape(data) + '</td></tr>';
+        };
+
+        connectButton.onclick = function() {
+            stateLabel.innerHTML = "Connecting";
+            socket = new WebSocket(connectionUrl.value);
+            socket.onopen = function (event) {
+                updateState();
+                commsLog.innerHTML += '<tr>' +
+                    '<td colspan="3" class="commslog-data">Connection opened</td>' +
+                '</tr>';
+            };
+            socket.onclose = function (event) {
+                updateState();
+                commsLog.innerHTML += '<tr>' +
+                    '<td colspan="3" class="commslog-data">Connection closed. Code: ' + htmlEscape(event.code) + '. Reason: ' + htmlEscape(event.reason) + '</td>' +
+                '</tr>';
+            };
+            socket.onerror = updateState;
+            socket.onmessage = function (event) {
+                commsLog.innerHTML += '<tr>' +
+                    '<td class="commslog-server">Server</td>' +
+                    '<td class="commslog-client">Client</td>' +
+                    '<td class="commslog-data">' + htmlEscape(event.data) + '</td></tr>';
+            };
+        };
+
+        function htmlEscape(str) {
+            return str.toString()
+                .replace(/&/g, '&amp;')
+                .replace(/"/g, '&quot;')
+                .replace(/'/g, '&#39;')
+                .replace(/</g, '&lt;')
+                .replace(/>/g, '&gt;');
+        }
+    </script>
+</body>
+</html>

src/DataStreamSuite/Bts.DataStreamWebApp.Server/wwwroot/index.html

@@ -0,0 +1,176 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8" />
+    <title></title>
+    <style>
+        table {
+            border: 0
+        }
+
+        .commslog-data {
+            font-family: Consolas, Courier New, Courier, monospace;
+        }
+
+        .commslog-server {
+            background-color: red;
+            color: white
+        }
+
+        .commslog-client {
+            background-color: green;
+            color: white
+        }
+    </style>
+</head>
+<body>
+    <h1>DataStreams via WebSocket</h1>
+    <p id="stateLabel">Ready to connect...</p>
+    <div>
+        <label for="connectionUrl">WebSocket Server URL:</label>
+        <input id="connectionUrl" />
+        <button id="connectButton" type="submit">Connect</button>
+    </div>
+    <p></p>
+    <div>
+        <label for="sendMessage">Query:</label>
+        <input id="sendMessage" disabled />
+        <button id="sendButton" type="submit" disabled>Send</button>
+        <button id="closeButton" disabled>Close Socket</button>
+    </div>
+
+    <h2>Communication Log</h2>
+    <table style="width: 800px">
+        <thead>
+            <tr>
+                <td style="width: 100px">From</td>
+                <td style="width: 100px">To</td>
+                <td>Data</td>
+            </tr>
+        </thead>
+        <tbody id="commsLog">
+        </tbody>
+    </table>
+
+    <script>
+        var connectionUrl = document.getElementById("connectionUrl");
+        var connectButton = document.getElementById("connectButton");
+        var stateLabel = document.getElementById("stateLabel");
+        var sendMessage = document.getElementById("sendMessage");
+        var sendButton = document.getElementById("sendButton");
+        var commsLog = document.getElementById("commsLog");
+        var closeButton = document.getElementById("closeButton");
+        var socket;
+
+        var scheme = document.location.protocol === "https:" ? "wss" : "ws";
+        var port = document.location.port ? (":" + document.location.port) : "";
+
+        connectionUrl.value = scheme + "://" + document.location.hostname + port + "/ws" ;
+
+        function updateState() {
+            function disable() {
+                sendMessage.disabled = true;
+                sendButton.disabled = true;
+                closeButton.disabled = true;
+            }
+            function enable() {
+                sendMessage.disabled = false;
+                sendButton.disabled = false;
+                closeButton.disabled = false;
+            }
+
+            connectionUrl.disabled = true;
+            connectButton.disabled = true;
+
+            if (!socket) {
+                disable();
+            } else {
+                switch (socket.readyState) {
+                    case WebSocket.CLOSED:
+                        stateLabel.innerHTML = "Closed";
+                        disable();
+                        connectionUrl.disabled = false;
+                        connectButton.disabled = false;
+                        break;
+                    case WebSocket.CLOSING:
+                        stateLabel.innerHTML = "Closing...";
+                        disable();
+                        break;
+                    case WebSocket.CONNECTING:
+                        stateLabel.innerHTML = "Connecting...";
+                        disable();
+                        break;
+                    case WebSocket.OPEN:
+                        stateLabel.innerHTML = "Open";
+                        enable();
+                        break;
+                    default:
+                        stateLabel.innerHTML = "Unknown WebSocket State: " + htmlEscape(socket.readyState);
+                        disable();
+                        break;
+                }
+            }
+        }
+
+        closeButton.onclick = function () {
+            if (!socket || socket.readyState !== WebSocket.OPEN) {
+                alert("socket not connected");
+            }
+            socket.close(1000, "Closing from client");
+        };
+
+        sendButton.onclick = function () {
+            if (!socket || socket.readyState !== WebSocket.OPEN) {
+                alert("socket not connected");
+            }
+            const rpcReq = {
+              jsonrpc: "2.0",
+              method: "subscribe",
+              params: {
+                query: sendMessage.value,
+              },
+              id: 1,
+            };
+            const rpcReqStr = JSON.stringify(rpcReq);
+            socket.send(rpcReqStr);
+            commsLog.innerHTML += '<tr>' +
+                '<td class="commslog-client">Client</td>' +
+                '<td class="commslog-server">Server</td>' +
+                '<td class="commslog-data">' + htmlEscape(rpcReqStr) + '</td></tr>';
+        };
+
+        connectButton.onclick = function() {
+            stateLabel.innerHTML = "Connecting";
+            socket = new WebSocket(connectionUrl.value);
+            socket.onopen = function (event) {
+                updateState();
+                commsLog.innerHTML += '<tr>' +
+                    '<td colspan="3" class="commslog-data">Connection opened</td>' +
+                '</tr>';
+            };
+            socket.onclose = function (event) {
+                updateState();
+                commsLog.innerHTML += '<tr>' +
+                    '<td colspan="3" class="commslog-data">Connection closed. Code: ' + htmlEscape(event.code) + '. Reason: ' + htmlEscape(event.reason) + '</td>' +
+                '</tr>';
+            };
+            socket.onerror = updateState;
+            socket.onmessage = function (event) {
+                commsLog.innerHTML += '<tr>' +
+                    '<td class="commslog-server">Server</td>' +
+                    '<td class="commslog-client">Client</td>' +
+                    '<td class="commslog-data">' + htmlEscape(event.data) + '</td></tr>';
+            };
+        };
+
+        function htmlEscape(str) {
+            return str.toString()
+                .replace(/&/g, '&amp;')
+                .replace(/"/g, '&quot;')
+                .replace(/'/g, '&#39;')
+                .replace(/</g, '&lt;')
+                .replace(/>/g, '&gt;');
+        }
+    </script>
+</body>
+</html>

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.Console/DataStream.Console.csproj

@@ -7,7 +7,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>

src/DataStreamSuite/DataStream.Console/Program.cs

@@ -1,4 +1,6 @@
 // See https://aka.ms/new-console-template for more information
+using BCG;
+
 using DataStream.Console;
 
 using ExpressionTests;
@@ -7,26 +9,43 @@ using Spark.Core.Collections;
 
 using System.Reactive.Disposables;
 
+var schema = new BlueTableSchema([
+      new("id", 0, typeof(int)),
+      new("name", 1, typeof(string)),
+      new("value", 2, typeof(int)),
+   ],
+   "MyTable"
+);
+var rows = new BlueTable(schema);
+var mbr = new MutableBlueRow(schema);
+mbr.setValue("id", 1);
+mbr.setValue("name", "Jerry");
+mbr.setValue("value", 13);
+rows.addRow(mbr);
+var serializer = new UniversalSerializer(schema);
+serializer.serialize(StreamOpCode.create, new[] { rows }, out var bytes);
+var bytesDesc = BitConverter.ToString(bytes).Replace("-", "\\x");
+Console.WriteLine(bytesDesc);
 
-try {
-   foreach (var arg in args) {
-      if (File.Exists(arg)) {
-         using var fs = File.OpenRead(arg) ??
-            throw new Exception("File.OpenRead returned null. LIES!");
-         var expressionLines = new StringStreamEnumerable(new(fs));
-         var test = ExpressionTestParser.Parse(expressionLines);
-         TempExpressionTests.Run(test);
-      }
-   }
-   if (args.Length == 0) {
-      TempExpressionTests.Run("rv = 3 + 4", new Dictionary<string, string> { { "rv", "7" } });
-   }
-} catch (Exception ex) {
-   using (ConsoleHelper.PushBg(ConsoleColor.Red)) {
-      Console.WriteLine($"Failed! {ex}");
-   }
-   return;
-}
+// try {
+//    foreach (var arg in args) {
+//       if (File.Exists(arg)) {
+//          using var fs = File.OpenRead(arg) ??
+//             throw new Exception("File.OpenRead returned null. LIES!");
+//          var expressionLines = new StringStreamEnumerable(new(fs));
+//          var test = ExpressionTestParser.Parse(expressionLines);
+//          TempExpressionTests.Run(test);
+//       }
+//    }
+//    if (args.Length == 0) {
+//       TempExpressionTests.Run("rv = 3 + 4", new Dictionary<string, string> { { "rv", "7" } });
+//    }
+// } catch (Exception ex) {
+//    using (ConsoleHelper.PushBg(ConsoleColor.Red)) {
+//       Console.WriteLine($"Failed! {ex}");
+//    }
+//    return;
+// }
 
-using var _ = ConsoleHelper.PushFg(ConsoleColor.Green);
-Console.WriteLine($"Passed!");
+// using var _ = ConsoleHelper.PushFg(ConsoleColor.Green);
+// Console.WriteLine($"Passed!");

src/DataStreamSuite/DataStream/DataStream.csproj

@@ -9,6 +9,8 @@
     <ProjectReference Include="..\ArithmeticExpressions\ArithmeticExpressions.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" />

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/Primitives/AddColumns/AddColumnsStream.cs

@@ -1,11 +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/ColumnAdder.cs

@@ -1,63 +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/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;
-
-
-// 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;
-
-//       public SortStream (ViewStream stream, string sortExpression)
-//       {
-//          myStream = stream;
-//          mySetSortExpression (sortExpression);
-//       }
-
-//       public SortStream (ViewStream vs, string colName, bool isAsc)
-//       {
-//          myStream = vs;
-//          string sortExpression = isAsc ? "+" + colName : "-" + colName;
-//          mySetSortExpression (sortExpression);
-//       }
-
-//       public SortStream (ViewStream vs, IComparer comparer)
-//       {
-//          myStream = vs;
-//          myComparer = comparer;
-//       }
-
-//       public string sortExpression
-//       {
-//          set
-//          {
-//             myComparer = null;
-//             myLastFiredPacket = null;
-//             mySetSortExpression (value);   
-//             myChangeHandler (myLastRecievedPacket);
-//          }
-//       }
-
-//       public IComparer comparer
-//       {
-//          set
-//          {
-//             myComparer = value;
-//             myLastFiredPacket = null;
-//             myChangeHandler(myLastRecievedPacket);
-//          }
-//       }
-
-//       private void mySetSortExpression (string sortExpression)
-//       {
-//          syntax parser = 
-//             new syntax();
-         
-//          mySortCols = ((SortExpression)
-//             parser.Parse (sortExpression)).columns;
-//       }
-
-//       protected override void myOnFirstSubscriber()
-//       {
-//          myStream.onChange += new DataStream.ChangeDelegate (myChangeHandler); 
-//       }
-
-//       protected override void myOnLastSubscriber()
-//       {
-//          myInit ();
-//          myStream.onChange -= new DataStream.ChangeDelegate (myChangeHandler); 
-//       }
-
-//       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());
-//       }
-
-//       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;
-//       }
-// 	}
-// }
+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 {
+   ViewStream stream;
+   IList<ColumnSortExpression> sortCols;
+   IComparer? comparer;
+   DataPacket? lastFiredPacket;
+   DataPacket? lastReceivedPacket;
+
+   public SortStream(ViewStream stream, string sortExpression) {
+      this.stream = stream;
+      SortExpression = sortExpression;
+   }
+
+   public SortStream(ViewStream vs, string colName, bool isAsc) {
+      stream = vs;
+      SortExpression = isAsc ? "+" + colName : "-" + colName;
+   }
+
+   public SortStream(ViewStream stream, IComparer comparer) {
+      this.stream = stream;
+      this.comparer = comparer;
+      sortCols = Array.Empty<ColumnSortExpression>();
+   }
+
+   [MemberNotNull(nameof(sortCols))]
+   public string SortExpression {
+      set {
+         comparer = null;
+         lastFiredPacket = null;
+         sortCols = ColumnSortExpressionInterpreter.Evaluate(value);
+         if (lastReceivedPacket is not null) {
+            myChangeHandler(lastReceivedPacket);
+         }
+      }
+   }
+
+   public IComparer Comparer {
+      set {
+         comparer = value;
+         lastFiredPacket = null;
+         if (lastReceivedPacket is not null) {
+            myChangeHandler(lastReceivedPacket);
+         }
+      }
+   }
+
+   public void myChangeHandlerTest(object o) =>
+      myChangeHandler(o);
+
+   [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());
+   }
+
+   protected override void myOnFirstSubscriber() =>
+      stream.onChange += myChangeHandler;
+
+   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/DataStreamCore/BlueData/BlueDataUtility.cs

@@ -48,6 +48,12 @@ namespace BCG {
             rv.Add(r.get<T>(col));
          return rv;
       }
+      public static IEnumerable<T> get_colvalues<T>(IBlueRowCollection rows, string col) {
+         List<T> rv = new List<T>();
+         foreach (IBlueRow r in rows)
+            rv.Add(r.get<T>(col));
+         return rv;
+      }
 
       public static IDictionary<T, IEnumerable<IBlueRow>> group_by<T>(IBlueRowCollection rows, string gp_col) {
          Dictionary<T, List<IBlueRow>> rv = new Dictionary<T, List<IBlueRow>>();
@@ -241,6 +247,68 @@ namespace BCG {
          return new BlueTableSchema(table_name, cis.ToArray());
       }
 
+      public static TypeCode convert_column_type(IEnumerable<string> col_vals) {
+         // bool
+         bool success = true;
+         foreach (var val in col_vals) {
+            bool parsed_val;
+            success = success && Boolean.TryParse(val, out parsed_val);
+            if (!success)
+               break;
+         }
+         if (success)
+            return TypeCode.Boolean;
+         // int
+         success = true;
+         foreach (var val in col_vals) {
+            int parsed_val;
+            success = success && Int32.TryParse(val, out parsed_val);
+            if (!success)
+               break;
+         }
+         if (success)
+            return TypeCode.Int32;
+         // try double
+         success = true;
+         foreach (var val in col_vals) {
+            double parsed_val;
+            success = success && Double.TryParse(val, out parsed_val);
+            if (!success)
+               break;
+         }
+         if (success)
+            return TypeCode.Double;
+         // try DateTime
+         success = true;
+         foreach (var val in col_vals) {
+            DateTime parsed_val;
+            success = success && DateTime.TryParse(val, out parsed_val);
+            if (!success)
+               break;
+         }
+         if (success)
+            return TypeCode.DateTime;
+         bts.Log.assert(false);
+         return TypeCode.Empty;
+      }
+
+      public static IBlueTableSchema to_typed_schema(IBlueRowCollection rows) {
+         List<ColumnInfo> cis = new List<ColumnInfo>();
+         foreach (var col in rows.schema.columnInfo) {
+            var text_vals = BlueDataUtility.get_colvalues<string>(rows, col.colName);
+            TypeCode type_code = convert_column_type(text_vals);
+            cis.Add(new ColumnInfo(col.colName, cis.Count, _typecode_to_type[type_code]));
+         }
+         return new BlueTableSchema(cis.ToArray(), rows.schema.tableName);
+      }
+
+      // public static IBlueRow convert_string_row(IBlueRow r, IBlueTableSchema out_schema) {
+      //    foreach (var ci in out_schema.columnInfo){
+
+      //    }
+      // }
+
+
       /// <summary>
       /// Gets the Hashcode of the row with the boolean indicating whether the order of the rows should
       /// be alphabetic or not

src/DataStreamSuite/DataStreamCore/BlueData/ColumnInfo.cs

@@ -1,95 +1,103 @@
-using System;
-
-namespace BCG
-{
-   /// <summary>
-   /// Resprsents information about a column schema, ie its ordinal, the type, the name and constant value or expression. where applicable
-   /// </summary>
-   [Serializable]
-   public class ColumnInfo : IComparable
-   {
-      public static bool isAllowedType (Type t)
-      {
-         return 
-            t.Equals (typeof (System.Int32)) ||
-            t.Equals (typeof (System.Int64)) ||
-            t.Equals (typeof (System.Double)) ||
-            t.Equals (typeof (System.String)) ||
-            t.Equals (typeof (System.DateTime)) ? true :
-            false;
-      }
-
-      //the default column info does not cach values in a lookup table, therefore it is in group 0
-      public ColumnInfo(string colName, int colNo, Type colType)
-         : this(colName, colNo, colType, 0)
-      {
-
-
-      }
-
-      public ColumnInfo(string colName, int colNo, Type colType, short colGroup)
-      {
-         myColName = colName;
-         myColNo = colNo;
-         myColType = colType;
-         myLookupTableGroup = colGroup;
-         myColValue = null;
-      }
-
-
-      public ColumnInfo (string colName, int colNo, object colValue)
-         : this (colName, colNo, colValue.GetType())  {myColValue = colValue == null ? DBNull.Value : colValue;}
-
-      public ColumnInfo (string colName, int colNo, Type colType, object colValue)
-         : this (colName, colNo, colType) 
-      {
-
-         myColValue = colValue == null ? DBNull.Value : colValue;
-      
-      }
-
-
-      public int CompareTo (object obj)
-      {
-         int otherColNo = ((ColumnInfo)(obj)).colNo;
-         if (myColNo < otherColNo)
-            return -1;
-         else if (myColNo > otherColNo)
-            return 1;
-         return 0;
-      }
-
-      //public bool isCalculated{get{return myExpression != null;}}
-
-      public bool isConstant {get{return myColValue != null;}}
-
-      private int myColNo;
-      private string myColName;
-      private Type myColType;
-      //private string myExpression;
-      private object myColValue;
-
-      //no table will ever have more than 65,536 columns
-      //if it does, we are in serious trouble
-      private short myLookupTableGroup;
-
-      public int colNo{get{return myColNo;}}
-      public string colName {get{return myColName;}}
-      public Type colType {get{return myColType;}}
-
-
-      //this value corresponds to how the data in the column is serialized. 
-      //if the group number is 0, the values are not stored in a table
-      //if the vlaue is non-zero, all columns with the the same lookup table group are stored in the same lookup table together
-      //are stored together in a lookup table
-
-      
-      public short lookupTableGroup
-      {
-         get { return myLookupTableGroup; }
-         set { myLookupTableGroup = value; }
-      }
-      //public string expression {get{return myExpression;}}
-      public object colValue {get{return myColValue;}}
-   }
-}
+using System;
+using System.Text.Json.Serialization;
+
+namespace BCG
+{
+   /// <summary>
+   /// Resprsents information about a column schema, ie its ordinal, the type, the name and constant value or expression. where applicable
+   /// </summary>
+   [Serializable]
+   public class ColumnInfo : IComparable
+   {
+      public static bool isAllowedType (Type t)
+      {
+         return 
+            t.Equals (typeof (System.Int32)) ||
+            t.Equals (typeof (System.Int64)) ||
+            t.Equals (typeof (System.Double)) ||
+            t.Equals (typeof (System.String)) ||
+            t.Equals (typeof (System.DateTime)) ? true :
+            false;
+      }
+
+      //the default column info does not cach values in a lookup table, therefore it is in group 0
+      public ColumnInfo(string colName, int colNo, Type colType)
+         : this(colName, colNo, colType, 0)
+      {
+
+
+      }
+
+      public ColumnInfo(string colName, int colNo, Type colType, short colGroup)
+      {
+         myColName = colName;
+         myColNo = colNo;
+         myColType = colType;
+         myLookupTableGroup = colGroup;
+         myColValue = null;
+      }
+
+
+      public ColumnInfo (string colName, int colNo, object colValue)
+         : this (colName, colNo, colValue.GetType())  {myColValue = colValue == null ? DBNull.Value : colValue;}
+
+      public ColumnInfo (string colName, int colNo, Type colType, object colValue)
+         : this (colName, colNo, colType) 
+      {
+
+         myColValue = colValue == null ? DBNull.Value : colValue;
+      
+      }
+
+
+      public int CompareTo (object obj)
+      {
+         int otherColNo = ((ColumnInfo)(obj)).colNo;
+         if (myColNo < otherColNo)
+            return -1;
+         else if (myColNo > otherColNo)
+            return 1;
+         return 0;
+      }
+
+      //public bool isCalculated{get{return myExpression != null;}}
+
+      public bool isConstant {get{return myColValue != null;}}
+
+      private int myColNo;
+      private string myColName;
+      private Type myColType;
+      //private string myExpression;
+      private object myColValue;
+
+      //no table will ever have more than 65,536 columns
+      //if it does, we are in serious trouble
+      private short myLookupTableGroup;
+
+      [JsonPropertyName("index")]
+      public int colNo{get{return myColNo;}}
+
+      [JsonPropertyName("name")]
+      public string colName {get{return myColName;}}
+
+      [JsonPropertyName("type")]
+      public Type colType {get{return myColType;}}
+
+
+      //this value corresponds to how the data in the column is serialized. 
+      //if the group number is 0, the values are not stored in a table
+      //if the vlaue is non-zero, all columns with the the same lookup table group are stored in the same lookup table together
+      //are stored together in a lookup table
+
+      
+      [JsonIgnore]
+      public short lookupTableGroup
+      {
+         get { return myLookupTableGroup; }
+         set { myLookupTableGroup = value; }
+      }
+      //public string expression {get{return myExpression;}}
+      [JsonIgnore]
+      public object colValue {get{return myColValue;}}
+   }
+}

src/DataStreamSuite/DataStreamCore/BlueRowJsonConverter.cs

@@ -0,0 +1,63 @@
+// #nullable enable
+// using BCG;
+
+// using Spark.Core.Json;
+
+// using System;
+// using System.Text.Json;
+// using System.Text.Json.Nodes;
+// using System.Text.Json.Serialization;
+
+// namespace Bts.DataStreamCore;
+
+// class BlueRowJsonConverter : JsonConverter<IBlueRow> {
+//    public override IBlueRow Read(
+//       ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+//       var row = JsonSerializer.Deserialize<JsonObject>(ref reader, options)!;
+//       var schemaj = row["schema"]!.GetValue<JsonObject>() ??
+//          throw new InvalidOperationException("Failed to read schema");
+//       // var columns = schemaj["columns"]
+//       var mbr = new MutableBlueRow(schema);
+//       int colNum = 0;
+//       switch (reader.TokenType) {
+//          case JsonTokenType.StartArray:
+//             while (reader.Read() && reader.TokenType != JsonTokenType.EndArray) {
+//                mbr.setValue(colNum++, readCellValue(ref reader));
+//                colNum++;
+//             }
+//             break;
+//          case JsonTokenType.StartObject:
+//             while (reader.Read() && reader.TokenType != JsonTokenType.EndObject) {
+//                if (reader.TokenType != JsonTokenType.PropertyName) {
+//                   throw new InvalidOperationException(
+//                      "Expected 'PropertyName' immediately after 'StartObject' token in row json");
+//                }
+//                var colName = reader.GetString();
+//                if (!reader.Read()) {
+//                   throw new InvalidOperationException(
+//                      "Failed to read token immediately after 'PropertyName' token in row json");
+//                }
+//                mbr.setValue(colName, readCellValue(ref reader));
+//             }
+//             break;
+//       }
+//       if (mbr.Count != schema.columnInfo.Length) {
+//          throw new InvalidOperationException(
+//             $"Row json array length '{mbr.Count}' does not match the schema's " +
+//             $"column length '{schema.columnInfo.Length}'.");
+//       }
+//       return mbr;
+
+//       static object? readCellValue(ref Utf8JsonReader reader) =>
+//          reader.TokenType switch {
+//             JsonTokenType.String => reader.GetString(),
+//             JsonTokenType.Number => reader.GetDouble(),
+//             JsonTokenType.True or JsonTokenType.False => reader.GetBoolean(),
+//             _ => throw new InvalidOperationException("Failed to read cell value"),
+//          };
+//    }
+
+//    public override void Write(Utf8JsonWriter writer, IBlueRow value, JsonSerializerOptions options) {
+//       throw new NotImplementedException();
+//    }
+// }

src/DataStreamSuite/DataStreamCore/DataPacketJsonConverter.cs

@@ -0,0 +1,186 @@
+// #nullable enable
+// using BCG;
+
+// using Spark.Core.Json;
+
+// using System;
+// using System.Collections.Generic;
+// using System.Text.Json;
+// using System.Text.Json.Nodes;
+// using System.Text.Json.Serialization;
+
+// namespace Bts.DataStreamCore;
+
+// public class DataStreamUpdateJsonConverter : JsonConverter<DataStreamUpdate> {
+//    /// <summary>
+//    /// Whether or not to include a field for current rows (i.e., snapshot of current state). By
+//    /// default, only incremental changes are included ('added' and 'deleted').
+//    /// </summary>
+//    public bool IncludeCurrent { get; set; }
+
+//    /// <summary>
+//    /// Whether to treat rows as objects (name/value pairs), or arrays (list of values). Arrays
+//    /// result in smaller payloads, but aren't as easy to read as name/value pairs (for mere humans).
+//    /// </summary>
+//    public bool UseObjectRows { get; set; }
+
+//    public override DataStreamUpdate? Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options) {
+//       var dpj = JsonSerializer.Deserialize<JsonObject>(ref reader);
+//       if (dpj is null) {
+//          return null;
+//       }
+//       var tableName = dpj["tableName"]!.AsString();
+//       var columns = dpj["columns"]!.AsArray()
+//          .Select((c, i) => {
+//             var dataType = c!["type"]!.AsEnum<DataStreamDataType>();
+//             return (info: new ColumnInfo(c["name"]!.AsString(), i, dataType.ToType()), dataType);
+//          })
+//          .ToArray();
+//       var schema = new BlueTableSchema(columns.Cut1().ToArray(), tableName);
+//       return new() {
+//          TableName = tableName,
+//          AddedRows = ToRows(dpj.GetArrayOrEmpty("added")).ToList(),
+//          DeletedRows = ToRows(dpj.GetArrayOrEmpty("deleted")).ToList(),
+//          Columns = [.. schema.columnInfo]
+//       };
+
+//       IEnumerable<IBlueRow> ToRows(JsonArray rows) {
+//          foreach (var row in rows) {
+//             var mbr = new MutableBlueRow(schema);
+//             switch (row!.GetValueKind()) {
+//                case JsonValueKind.Object:
+//                   var rowObj = row.AsObject();
+//                   for (int i = 0; i < columns.Length; i++) {
+//                      SetCellValue(mbr, i, rowObj[columns[i].info.colName]!, columns[i].dataType);
+//                   }
+//                   break;
+//                case JsonValueKind.Array:
+//                   var rowArr = row.AsArray();
+//                   for (int i = 0; i < columns.Length; i++) {
+//                      SetCellValue(mbr, i, rowArr[i]!, columns[i].dataType);
+//                   }
+//                   break;
+//             }
+//             yield return mbr;
+//          }
+//       }
+
+//       static void SetCellValue(MutableBlueRow mbr, int i, JsonNode cell, DataStreamDataType dataType) {
+//          switch (dataType) {
+//             case DataStreamDataType.String:
+//                mbr.setValue(i, cell.GetValue<string>());
+//                break;
+//             case DataStreamDataType.Int32:
+//                mbr.setValue(i, cell.GetValue<int>());
+//                break;
+//             case DataStreamDataType.Int64:
+//                mbr.setValue(i, cell.GetValue<long>());
+//                break;
+//             case DataStreamDataType.Single:
+//                mbr.setValue(i, cell.GetValue<float>());
+//                break;
+//             case DataStreamDataType.Double:
+//                mbr.setValue(i, cell.GetValue<double>());
+//                break;
+//          }
+//       }
+//    }
+
+//    public override void Write(Utf8JsonWriter writer, DataStreamUpdate value, JsonSerializerOptions options) {
+//       using var _ = writer.WriteObject();
+//       writer.WriteString("tableName", value.TableName);
+//       using (writer.WriteArray("columns")) {
+//          foreach (var col in value.Columns.empty_if_null()) {
+//             using (writer.WriteObject()) {
+//                writer.WriteString("name", col.colName);
+//                writer.WriteNumber("index", col.colNo);
+//                // TODO: use language agnostic type names (e.g., 'string', 'integer', 'float', 'date' etc.)
+//                writer.WriteString("type", col.colType.ToString());
+//             }
+//          }
+//       }
+
+//       var cellWriters = value.Columns!.Select(getCellWriter).ToList();
+//       using (writer.WriteArray("added")) {
+//          foreach (IBlueRow row in value.AddedRows!) {
+//             using (writer.WriteArray()) {
+//                for (int i = 0; i < cellWriters.Count; i++) {
+//                   cellWriters[i](row[i]);
+//                }
+//             }
+//          }
+//       }
+//       using (writer.WriteArray("deleted")) {
+//          foreach (IBlueRow row in value.DeletedRows!) {
+//             using (writer.WriteArray()) {
+//                for (int i = 0; i < cellWriters.Count; i++) {
+//                   cellWriters[i](row[i]);
+//                }
+//             }
+//          }
+//       }
+//       if (IncludeCurrent) {
+//          using (writer.WriteArray("current")) {
+//             foreach (IBlueRow row in value.newRows) {
+//                using (writer.WriteArray()) {
+//                   for (int i = 0; i < cellWriters.Count; i++) {
+//                      cellWriters[i](row[i]);
+//                   }
+//                }
+//             }
+//          }
+//       }
+
+//       Action<object?> getCellWriter(ColumnInfo colInfo) {
+//          var writeVal = getCellValueWriter(colInfo);
+//          if (!UseObjectRows) {
+//             return writeVal;
+//          }
+//          return v => {
+//             writer.WritePropertyName(colInfo.colName);
+//             writeVal(v);
+//          };
+//       }
+
+//       Action<object?> getCellValueWriter(ColumnInfo colInfo) {
+//          var t = colInfo.colType;
+//          if (t == typeof(int)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((int)v));
+//          }
+//          if (t == typeof(uint)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((uint)v));
+//          }
+//          if (t == typeof(long)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((long)v));
+//          }
+//          if (t == typeof(ulong)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((ulong)v));
+//          }
+//          if (t == typeof(short)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((short)v));
+//          }
+//          if (t == typeof(ushort)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((ushort)v));
+//          }
+//          if (t == typeof(double)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((double)v));
+//          }
+//          if (t == typeof(float)) {
+//             return nullCheckWrapper(v => writer.WriteNumberValue((float)v));
+//          }
+//          if (t == typeof(bool)) {
+//             return nullCheckWrapper(v => writer.WriteBooleanValue((bool)v));
+//          }
+//          return nullCheckWrapper(v => writer.WriteStringValue(v?.ToString()));
+
+//          Action<object?> nullCheckWrapper(Action<object> writeNonNull) =>
+//             v => {
+//                if (v is null) {
+//                   writer.WriteNullValue();
+//                } else {
+//                   writeNonNull(v);
+//                }
+//             };
+//       }
+//    }
+// }

src/DataStreamSuite/DataStreamCore/DataStreamCore.csproj

@@ -4,6 +4,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <TargetFramework>net8.0</TargetFramework>
     <Nullable>disable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
   </PropertyGroup>
 
   <ItemGroup>

src/DataStreamSuite/DataStreamCore/DataStreamDataType.cs

@@ -0,0 +1,11 @@
+namespace Bts.DataStreamCore;
+
+public enum DataStreamDataType {
+   Any,
+   Bytes,
+   String,
+   Int32,
+   Int64,
+   Single,
+   Double
+}

src/DataStreamSuite/DataStreamCore/DataStreamExtensions.cs

@@ -0,0 +1,42 @@
+#nullable enable
+
+using Bts.DataStreamCore;
+
+public static class DataStreamExtensions {
+   public static Type ToType(this DataStreamDataType dataType) =>
+      dataType switch {
+         DataStreamDataType.Any => typeof(object),
+         DataStreamDataType.String => typeof(string),
+         DataStreamDataType.Int32 => typeof(int),
+         DataStreamDataType.Int64 => typeof(long),
+         DataStreamDataType.Single => typeof(float),
+         DataStreamDataType.Double => typeof(double),
+         _ => throw new ArgumentException($"DataType '{dataType}' not supported.", nameof(dataType)),
+      };
+
+   public static DataStreamDataType FromType(Type type) {
+      if (type == typeof(object)) {
+         return DataStreamDataType.Any;
+      }
+      if (type == typeof(string)) {
+         return DataStreamDataType.String;
+      }
+      if (type == typeof(int)) {
+         return DataStreamDataType.Int32;
+      }
+      if (type == typeof(long)) {
+         return DataStreamDataType.Int64;
+      }
+      if (type == typeof(float)) {
+         return DataStreamDataType.Single;
+      }
+      if (type == typeof(double)) {
+         return DataStreamDataType.Double;
+      }
+      if (type == typeof(byte[])) {
+         return DataStreamDataType.Bytes;
+      }
+      throw new ArgumentException(
+         $"Unable to convert type '{type}' to {typeof(DataStreamDataType)}");
+   }
+}

src/DataStreamSuite/DataStreamCore/DataStreamUpdate.cs

@@ -0,0 +1,41 @@
+#nullable enable
+using BCG;
+
+using Spark.Core.Json;
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+namespace Bts.DataStreamCore;
+
+public class DataStreamUpdate {
+   [JsonPropertyName("tableName")]
+   public string? TableName { get; set; }
+
+   [JsonPropertyName("columns")]
+   public List<ColumnInfo>? Columns { get; set; }
+
+   [JsonPropertyName("addedRows")]
+   public List<IBlueRow>? AddedRows { get; set; }
+
+   [JsonPropertyName("deletedRows")]
+   public List<IBlueRow>? DeletedRows { get; set; }
+
+   public DataPacket ToDataPacket(BlueTable state, bool applyChanges = true) {
+      var schema = new BlueTableSchema([.. Columns!], TableName);
+      var addedRowsTable = new BlueTable(schema);
+      var deletedRowsTable = new BlueTable(schema);
+      if (applyChanges) {
+         state.deleteRows(deletedRowsTable);
+         state.addRows(addedRowsTable);
+      }
+      return new(state, addedRowsTable, deletedRowsTable);
+   }
+
+   public static string ToJson() {
+      return "";
+   }
+}

src/DataStreamSuite/DataStreamCore/Usings.cs

@@ -0,0 +1 @@
+using System.Linq;

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/DataStreamPublisher/Configurations/MarketDataPublisher.json

@@ -0,0 +1,12 @@
+{
+  "user": "bts",
+  "prepublish_tables": {
+    "bbo": "bbo()",
+    "instruments": "instruments()",
+    "timesales": "timesales(10000)",
+    "books": "books()",
+    "seconds_1_10": "second(1,10)",
+    "literal_420": "literal(\"x\", \"420.0\")",
+    "mongodb_testcollection": "mongodb(\"mongodb+srv://johnc-dev:DMhDhP!g-TKeK.5@atlas-online-archive-5e18ab3c77c74d1cffa64c03-m7jkr.a.query.mongodb.net/?ssl=true&authSource=admin\",\"admin\",\"test_collection\")"
+  }
+}

src/DataStreamSuite/DataStreamPublisher/Configurations/SimpleEchoClient.json

@@ -0,0 +1,4 @@
+{
+  "user": "bts",
+  "simple_echo_client": true
+}

src/DataStreamSuite/DataStreamPublisher/DataStreamPublisher.csproj

@@ -1,5 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="CommandLineParser" Version="2.9.1" />
+  </ItemGroup>
+
   <ItemGroup>
     <ProjectReference Include="..\..\client\spark_api\spark_api.csproj" />
     <ProjectReference Include="..\..\client\spark_core\spark_core.csproj" />
@@ -9,11 +20,4 @@
     <ProjectReference Include="..\PubSub\PubSub.csproj" />
   </ItemGroup>
 
-  <PropertyGroup>
-    <OutputType>Exe</OutputType>
-    <TargetFramework>net8.0</TargetFramework>
-    <Nullable>enable</Nullable>
-    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-  </PropertyGroup>
-
 </Project>

src/DataStreamSuite/DataStreamPublisher/DataStreamPublisherConfig.cs

@@ -0,0 +1,76 @@
+namespace Bts.DataStreamPublisher;
+
+using CommandLine;
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text.Json;
+using System.Text.Json.Serialization;
+
+public class DataStreamPublisherConfig {
+   /// <summary>
+   /// The login user for sparkd
+   /// </summary>
+   [JsonPropertyName("user")]
+   [Option("user", HelpText = "The sparkd login user")]
+   public string? User { get; set; }
+
+   /// <summary>
+   /// The login password for sparkd
+   /// </summary>
+   [JsonPropertyName("password")]
+   [Option("pass", HelpText = "The sparkd login password")]
+   public string? Password { get; set; }
+
+   /// <summary>
+   /// The config server url for sparkd
+   /// </summary>
+   [JsonPropertyName("sparkd")]
+   [Option("sparkd", HelpText = "The sparkd config server")]
+   public string? Sparkd { get; set; }
+
+   /// <summary>
+   /// The tables to publish on startup. Each key/value represents a table name/query to publish.
+   /// </summary>
+   [JsonPropertyName("prepublish_tables")]
+   public Dictionary<string, string>? PrepublishTables { get; set; }
+
+   [JsonPropertyName("simple_echo_client")]
+   [Option("simple-echo-client", HelpText = "Run a simple echo client (won't publish tables or connect to sparkd)")]
+   public bool? SimpleEchoClient { get; set; }
+
+   [Option(
+      "config",
+      MetaValue = "PATH",
+      HelpText = "Path to json file representing these options (DataStreamPublisherConfig)")]
+   [JsonIgnore]
+   public string? ConfigFile { get; set; }
+
+   public void MergeWith(DataStreamPublisherConfig other) {
+      User ??= other.User;
+      Password ??= other.Password;
+      Sparkd ??= other.Sparkd;
+      PrepublishTables ??= other.PrepublishTables;
+      SimpleEchoClient ??= other.SimpleEchoClient;
+      ConfigFile ??= other.ConfigFile;
+   }
+
+   /// <summary>
+   /// Merges options with those defined in `ConfigFile` (does not overwrite
+   /// non-null existing values).
+   /// </summary>
+   /// <exception cref="InvalidOperationException">
+   /// JsonSerializer.Deserialize returns null
+   /// </exception>
+   public void MergeWithConfigFile() {
+      if (ConfigFile is null) {
+         return;
+      }
+      var cfgString = File.ReadAllText(ConfigFile);
+      var parsedCfg = JsonSerializer.Deserialize<DataStreamPublisherConfig>(cfgString) ??
+         throw new InvalidOperationException($"Failed to parse json from {ConfigFile}");
+      MergeWith(parsedCfg);
+      ConfigFile = null;
+   }
+}

src/DataStreamSuite/DataStreamPublisher/Program.cs

@@ -1,91 +1,91 @@
-using System;
-using mbts.config;
-using bts.utils;
-using System.Threading.Tasks;
-using Bts.DataStreamExpressions;
-using System.Collections.Generic;
-
-using BCG;
-using System.Threading;
-
-
-bts.Log.Gen.info($"Starting DSPublisher");
-Console.WriteLine("Starting DSPublisher...");
-bool run_echo_tcp_client_only = false;
-static void init(string[] args) {
-   Func<string, string, Task> login = async (l, p) => {
-      var login = l;
-      var passwd = p;
-      var service_ctx = bts.api.core.ServiceContext.create();
-      await service_ctx.login(login, passwd);
-   };
-   BTSNativeMethods.provide_command_line(args, args.Length);
-   Configuration.initialize();
-   Task.Run(async () => await login("bts", String.Empty));
-}
-init(args);
-if (run_echo_tcp_client_only)
-   start_echo_client();
-else
-   _publish_streams();
-
-static ViewStream build_stream(string stream_expression) {
-   try {
-      bts.Log.Gen.info($"build_stream stream_expression: {stream_expression}");
-      var exp = DataStreamExpressionsInterpreter.Evaluate(stream_expression);
-      var rv = exp.getView(new Dictionary<string, StatementExpression>(0));
-      return rv;
-
-   } catch (Exception ex) {
-      bts.Log.assert(false, $"Could not build stream: {stream_expression} ex: {ex}");
-      return null;
-   }
-}
-
-static void start_echo_client() {
-   Console.WriteLine("Starting DSPublisher in TCP client echo mode, Hit key to continue");
-   Console.ReadLine();
-   SimpleTCPClient client = new SimpleTCPClient("127.0.0.1", 12345);
-   client.start();
-   while (true) {
-      System.Threading.Thread.Sleep(1000);
-   }
-   // await SimpleTCPClient.start("127.0.0.1", 12345);
-   // Task.Delay(1000000000).Wait();
-}
-
-void _publish_streams() {
-   PubTableBroker pb_broker = new PubTableBroker();
-   CloudStreamManager csm = new CloudStreamManager();
-   // get it from config
-   Dictionary<string, string> streams_to_publish = new Dictionary<string, string>() {
-        //{"bbo","bbo()"},
-        //{"instruments","instruments()"},
-        //{"timesales","timesales(10000)"},
-        //{"books","books()"},
-       {"seconds_1_10","second(1,10)"},
-        {"literal_420","literal(\"x\", \"420.0\")"},
-        {"mongodb_testcollection", "mongodb(\"mongodb://192.168.1.80:27017\",\"local\",\"test_collection\")"}
-        };
-   //  {"bbo_ts","timeSeries(bbo())"}
-
-   foreach (var kv in streams_to_publish) {
-      var name = kv.Key;
-      var exp = kv.Value;
-      BCG.ViewStream vs = build_stream(exp);
-      ViewPublisher vpub = new ViewPublisher(name, pb_broker, vs);
-      vs.onChange += on_change;
-   }
-   while (true) {
-      System.Threading.Thread.Sleep(TimeSpan.FromSeconds(1));
-      ViewStreamDatabase.instance.doWork();
-      csm.doWork();
-      MasterWorker.getInstance(false).doWork();
-   }
-}
-
-
-
-void on_change(object obj) {
-   bts.Log.Gen.info($"DSPublisher on_change dp: {obj}");
-}
+using BCG;
+
+using bts;
+using bts.api.core;
+using bts.utils;
+
+using Bts.DataStreamExpressions;
+using Bts.DataStreamPublisher;
+
+using CommandLine;
+
+using mbts.config;
+
+using System;
+using System.Collections.Generic;
+using System.Threading.Tasks;
+
+await Parser.Default.ParseArguments<DataStreamPublisherConfig>(args)
+   .MapResult(RunAsync, errs => Task.FromResult(1));
+
+async Task<int> RunAsync(DataStreamPublisherConfig cfg) {
+   try {
+      cfg.MergeWithConfigFile();
+      Configuration.initialize(cfg.Sparkd);
+      Log.Gen.info("Starting DataStreamPublisher");
+      var service_ctx = ServiceContext.create(cfg.Sparkd);
+      await service_ctx.login(cfg.User ?? "bts", cfg.Password ?? string.Empty);
+      if (cfg.SimpleEchoClient ?? false) {
+         start_echo_client();
+      } else {
+         _publish_streams(cfg.PrepublishTables ?? []);
+      }
+   } catch (Exception ex) {
+      // Write the error to console first, in case the logging system is compromised.
+      var error_msg = $"DataStreamPublisher threw exception:\n{ex}";
+      Console.Error.WriteLine(error_msg);
+      Console.Error.Flush();
+      bts.Log.Gen.error(error_msg);
+      return 1;
+   }
+   return 0;
+}
+
+static ViewStream build_stream(string stream_expression) {
+   try {
+      bts.Log.Gen.info($"build_stream stream_expression: {stream_expression}");
+      var exp = DataStreamExpressionsInterpreter.Evaluate(stream_expression);
+      var rv = exp.getView(new Dictionary<string, StatementExpression>(0));
+      return rv;
+
+   } catch (Exception ex) {
+      bts.Log.assert(false, $"Could not build stream: {stream_expression} ex: {ex}");
+      return null;
+   }
+}
+
+static void start_echo_client() {
+   Console.WriteLine("Starting DSPublisher in TCP client echo mode, Hit key to continue");
+   Console.ReadLine();
+   SimpleTCPClient client = new SimpleTCPClient("127.0.0.1", 12345);
+   client.start();
+   while (true) {
+      System.Threading.Thread.Sleep(1000);
+   }
+   // await SimpleTCPClient.start("127.0.0.1", 12345);
+   // Task.Delay(1000000000).Wait();
+}
+
+void _publish_streams(IEnumerable<KeyValuePair<string, string>> prepublish_streams) {
+   PubTableBroker pb_broker = new PubTableBroker();
+   CloudStreamManager csm = new CloudStreamManager();
+   foreach (var kv in prepublish_streams) {
+      var name = kv.Key;
+      var exp = kv.Value;
+      BCG.ViewStream vs = build_stream(exp);
+      ViewPublisher vpub = new ViewPublisher(name, pb_broker, vs);
+      vs.onChange += on_change;
+   }
+   while (true) {
+      System.Threading.Thread.Sleep(TimeSpan.FromSeconds(1));
+      ViewStreamDatabase.instance.doWork();
+      csm.doWork();
+      MasterWorker.getInstance(false).doWork();
+   }
+}
+
+
+
+void on_change(object obj) {
+   bts.Log.Gen.info($"DSPublisher on_change dp: {obj}");
+}

src/DataStreamSuite/DataStreamSuite.sln

@@ -38,6 +38,10 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DataStreamTests", "DataStre
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "SharedStreams", "SharedStreams\SharedStreams.csproj", "{C1EBC423-4668-43D4-B7E5-A291086BA823}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bts.ColumnExpressions", "Bts.ColumnExpressions\Bts.ColumnExpressions.csproj", "{134C3915-CB2B-494C-BD62-E0B18250CBF5}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bts.ColumnSortExpressions", "Bts.ColumnSortExpressions\Bts.ColumnSortExpressions.csproj", "{B038CB72-4E81-4AF1-976F-ED8655C2C3D6}"
+EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bts.DataStreamWebApp.Server", "Bts.DataStreamWebApp.Server\Bts.DataStreamWebApp.Server.csproj", "{6DE5E4CE-423E-4571-81F7-539D268D6059}"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Bts.DataStream.Websocket", "Bts.DataStream.Websocket\Bts.DataStream.Websocket.csproj", "{088655DA-3126-4F8A-9AC7-9061FDA891FF}"
@@ -52,6 +56,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExpressionTests", "Expressi
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ExpressionTester", "ExpressionTester\ExpressionTester.csproj", "{0908C8F3-5E8A-41C7-979C-1C7C38D431C8}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "DataStream.Console", "DataStream.Console\DataStream.Console.csproj", "{B2968D7D-A41A-41E0-940A-37C7C2CA9513}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -133,6 +139,14 @@ Global
 		{C1EBC423-4668-43D4-B7E5-A291086BA823}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C1EBC423-4668-43D4-B7E5-A291086BA823}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C1EBC423-4668-43D4-B7E5-A291086BA823}.Release|Any CPU.Build.0 = Release|Any CPU
+		{134C3915-CB2B-494C-BD62-E0B18250CBF5}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{134C3915-CB2B-494C-BD62-E0B18250CBF5}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{134C3915-CB2B-494C-BD62-E0B18250CBF5}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{134C3915-CB2B-494C-BD62-E0B18250CBF5}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B038CB72-4E81-4AF1-976F-ED8655C2C3D6}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B038CB72-4E81-4AF1-976F-ED8655C2C3D6}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B038CB72-4E81-4AF1-976F-ED8655C2C3D6}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B038CB72-4E81-4AF1-976F-ED8655C2C3D6}.Release|Any CPU.Build.0 = Release|Any CPU
 		{6DE5E4CE-423E-4571-81F7-539D268D6059}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
 		{6DE5E4CE-423E-4571-81F7-539D268D6059}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{6DE5E4CE-423E-4571-81F7-539D268D6059}.Release|Any CPU.ActiveCfg = Release|Any CPU
@@ -161,5 +175,9 @@ Global
 		{0908C8F3-5E8A-41C7-979C-1C7C38D431C8}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{0908C8F3-5E8A-41C7-979C-1C7C38D431C8}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{0908C8F3-5E8A-41C7-979C-1C7C38D431C8}.Release|Any CPU.Build.0 = Release|Any CPU
+		{B2968D7D-A41A-41E0-940A-37C7C2CA9513}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{B2968D7D-A41A-41E0-940A-37C7C2CA9513}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{B2968D7D-A41A-41E0-940A-37C7C2CA9513}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{B2968D7D-A41A-41E0-940A-37C7C2CA9513}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 EndGlobal

src/DataStreamSuite/ExpressionTester/ExpressionTester.csproj

@@ -6,7 +6,7 @@
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>

src/DataStreamSuite/ExpressionTests/ExpressionTests.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
 

src/DataStreamSuite/PubSub/ManagedTCP/AsyncTCPConnectionAcceptor_APM.cs

@@ -64,7 +64,7 @@ namespace bts {
             newConn.getPeerAddress(out ip, out port);
             string connMsg = String.Format("Connection to port {2} made from {0}:{1}", ip, port, _port);
             //         BlueEventLog.logEvent(connMsg, PS3LogLevels.connection);
-            //Console.WriteLine(connMsg);       
+            Console.WriteLine(connMsg);       
         }
 
 
@@ -72,4 +72,4 @@ namespace bts {
 
     }
 
-}
+}

src/DataStreamSuite/PubSub/ManagedTCP/AsyncTCPConnection_APM.cs

@@ -480,7 +480,6 @@ namespace bts {
                         _on_read_data_completely(rcv_message);
                         _read_next_msg();
                         return;
-                        return;
                      } else if (msg_type == HB_MSG_SIGNAL) {
                         _on_read_hb_completely(rcv_message);
                         _read_next_msg();
@@ -581,4 +580,4 @@ namespace bts {
          }
       }
    }
-}
+}

src/DataStreamSuite/PubSub/Testing/SimpleTCPServer2.cs

@@ -0,0 +1,42 @@
+using System;
+using System.Net;
+using System.Net.Sockets;
+using System.Text;
+
+namespace Bts.PubSub;
+
+public class SimpleTCPServer2 {
+   private static Socket? _acceptSocket;
+   private static int _port = 12345;
+
+   public static void StartServer() {
+      _acceptSocket = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);
+      IPEndPoint endpoint = new IPEndPoint(IPAddress.Any, _port);
+      _acceptSocket.Bind(endpoint);
+      _acceptSocket.Listen(250);
+
+      Console.WriteLine($"Server listening on port {_port}");
+
+      while (true) {
+         Socket clientSocket = _acceptSocket.Accept();
+         HandleClient(clientSocket);
+      }
+   }
+
+   static void HandleClient(Socket clientSocket) {
+      // Example: Echo back received messages
+      byte[] buffer = new byte[1024];
+      int bytesRead;
+
+      while ((bytesRead = clientSocket.Receive(buffer)) > 0) {
+         string receivedData = Encoding.UTF8.GetString(buffer, 0, bytesRead);
+         Console.WriteLine($"Received data: {receivedData}");
+
+         // Echo back to the client
+         clientSocket.Send(Encoding.UTF8.GetBytes(receivedData));
+      }
+
+      Console.WriteLine("Client disconnected");
+      clientSocket.Close();
+   }
+}

src/DataStreamSuite/PubSubServer/Program.cs

@@ -1,57 +1,43 @@
-using System;
-using System.Threading;
-using System.Threading.Tasks;
-using System.Linq;
-
-//using BCG.Utilities;
-//using BCG.Utilities.General;
-
-
-namespace BCG {
-   class PubSub2Main {
-
-      /// <summary>
-      /// The main entry point for the application.
-      /// </summary>
-      [STAThread]
-      public static void Main(string[] args) {
-         bool run_echo_tcp_server_only = false;
-         bts.utils.BTSNativeMethods.provide_command_line(new string[] { }, 0);
-         mbts.config.Configuration.initialize();
-         if (run_echo_tcp_server_only) {
-            Console.WriteLine("Running as TCP Echo server, Hit enter to continue");
-            Console.ReadLine();
-            SimpleTCPServer sts = new SimpleTCPServer(12345);
-            sts.init();
-            Task.Delay(1000000000).Wait();
-         }
-         if (args.Length > 0 && args[0] == "daemon")
-            args = args.Skip(1).ToArray();
-
-         //CoreServicesInit.init();
-         PubSub3Config config = PubSub3Config.instance;
-
-         long currentMemory = 0;
-         int defaultWaitTime = 100;
-         bool gced = false;
-         new Thread(() => {
-            while (true) {
-               gced = false;
-               currentMemory = GC.GetTotalMemory(false);
-               if (config.PS3_GCActivationThreshold > 0 && currentMemory > config.PS3_GCActivationThreshold) {
-                  string gcMsg = String.Format("GCing memory, mem before GC = {0}", currentMemory);
-                  // BlueEventLog.logEvent(gcMsg, PS3LogLevels.info);
-                  Console.WriteLine(gcMsg);
-                  GC.Collect();
-                  gced = true;
-               }
-               Thread.Sleep(gced ? config.PS3_WaitPeriodAfterGC : defaultWaitTime);
-            }
-         }).Start();
-
-         PubSubMessageReactor pubSubServer = new PubSubMessageReactor();
-         pubSubServer.start();
-
-      }
-   }
-}
+using BCG;
+
+using bts.utils;
+
+using mbts.config;
+
+using System;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+
+bool run_echo_tcp_server_only = true;
+Configuration.initialize();
+if (run_echo_tcp_server_only) {
+   Console.WriteLine("Running as TCP Echo server, Hit enter to continue");
+   Console.ReadLine();
+   var port = 12345;
+   Console.WriteLine($"ready to listen to port: {port}");
+   SimpleTCPServer sts = new SimpleTCPServer(port);
+   sts.init();
+   Task.Delay(1000000000).Wait();
+}
+
+PubSub3Config config = PubSub3Config.instance;
+
+long currentMemory = 0;
+int defaultWaitTime = 100;
+bool gced = false;
+new Thread(() => {
+   while (true) {
+      gced = false;
+      currentMemory = GC.GetTotalMemory(false);
+      if (config.PS3_GCActivationThreshold > 0 && currentMemory > config.PS3_GCActivationThreshold) {
+         Console.WriteLine($"GCing memory, mem before GC = {currentMemory}");
+         GC.Collect();
+         gced = true;
+      }
+      Thread.Sleep(gced ? config.PS3_WaitPeriodAfterGC : defaultWaitTime);
+   }
+}).Start();
+
+PubSubMessageReactor pubSubServer = new PubSubMessageReactor();
+pubSubServer.start();

src/DataStreamSuite/SharedStreams/Business/MarketData/PriceStatsStream.cs

@@ -1,125 +1,127 @@
-namespace BCG {
-   using BCG.Utilities.General;
-
-   using bts.api;
-   using bts.api.domain;
-   using bts.api.synthetic;
-   using bts.md;
-   using bts.spark;
-   using bts.utils;
-
-   using mbts;
-   using mbts.co2;
-   using mbts.config;
-   using mbts.spark;
-   using mbts.ui;
-
-   using Spark.Core.Data;
-   using Spark.Core.Disposables;
-   using Spark.Core.Reactive;
-
-   using System;
-   using System.Collections.Concurrent;
-   using System.Collections.Generic;
-   using System.Collections.ObjectModel;
-   using System.Linq;
-   using System.Reactive.Linq;
-   using bts.api.core;
-   using Spark.Api.MarketData;
-
-   using SecurityKey = System.UInt32;
-   using System.Data;
-   using System.Reflection.Metadata;
-
-   [DataStreamUserRespresentation("price_stats")]
-   public class PriceStatsStream : ViewStream, IWorker {
-      private readonly TimeSpan _poll_period = TimeSpan.FromMilliseconds(500);
-      private DateTime _last_poll_time = DateTime.MinValue;
-      private ViewStreamDatabase _vsd;
-      private int _id = 0;
-      IReadOnlyDictionary<SecurityKey, PriceStats> _cached_state = null;
-      MarketDataClient _md_client;
-      private bool _dirty = false;
-      private readonly IBlueTableSchema _pstats_scheam = BlueDataUtility.form_schema("bbo",
-                                                Tuple.Create("id", TypeCode.Int32),
-                                                Tuple.Create("sec_key", TypeCode.Int32),
-                                                Tuple.Create("sec", TypeCode.String),
-                                                Tuple.Create("open", TypeCode.UInt32),
-                                                Tuple.Create("close", TypeCode.Double),
-                                                Tuple.Create("settlement", TypeCode.Single));
-
-      // TODO: add cons for symbol, exchange etc 
-      public PriceStatsStream()
-      : this(ViewStreamDatabase.instance) {
-      }
-
-      public PriceStatsStream(ViewStreamDatabase vsd) {
-         bts.Log.Gen.info("PriceStatsStream.cons");
-         _vsd = vsd;
-         _md_client = new MarketDataClient(new MDSource(TimeSpan.FromSeconds(0.5)));
-      }
-
-      protected override void myOnFirstSubscriber() {
-         _vsd.addWorker(this);
-         _md_client.price_stats().Subscribe(_on_price_stats);
-      }
-
-      private void _log_updates(TableUpdate<PriceStats, uint> update) {
-         int i = 0;
-         // foreach (BookTuple bt in update.added) {
-         //    bts.Log.Gen.info($"PriceStatsStream added: idx: {i++} bid: {bt.book.bids[0].price} / {bt.book.bids[0].size} ask: {bt.book.asks[0].price} / {bt.book.asks[0].size}");
-         // }
-         // foreach (Change<BookTuple> c in update.changes) {
-         //    var bt = c.New;
-         //    bts.Log.Gen.info($"PriceStatsStream changes: idx: {i} bid: {bt.book.bids[0].price} / {bt.book.bids[0].size} ask: {bt.book.asks[0].price} / {bt.book.asks[0].size}");
-         // }
-      }
-
-      private void _on_price_stats(TableUpdate<PriceStats, uint> update) {
-         _log_updates(update);
-         // just cacching in here, will populate the rows in _poll_scan and fire the datapacket
-         bts.Log.Gen.info($"PriceStatsStream._on_price_stats state: {update.state.Count()} changes: {update.changes.Count()} added: {update.added.Count()}");
-         _cached_state = update.state;
-         _dirty = false;
-      }
-
-      protected override void myOnLastSubscriber() {
-         _vsd.removeWorker(this);
-      }
-
-      private void _scan() {
-         // this shouldn be made incremental using the TableUpdate
-         bts.Log.Gen.info("PriceStatsStream._scan_bbo");
-         if (_cached_state == null)
-            return;
-         BlueTable new_state = new BlueTable(_pstats_scheam);
-         foreach (var kv in _cached_state) {
-            SecurityKey skey = kv.Key;
-            int id = Convert.ToInt32(skey);
-            PriceStats pstats = kv.Value;
-            IBlueRow r = new BlueRow(_pstats_scheam, id, skey, pstats.security.ToString(), pstats.open, pstats.close, pstats.settlement);
-            new_state.addRow(r);
-         }
-         DataPacket dp = null;
-         if (myLastValue == null) {
-            dp = new DataPacket(new_state, new_state, new BlueTable(_pstats_scheam));
-         } else {
-            DataPacket old_dp = myLastValue as DataPacket;
-            IBlueRowCollection added_rows, del_rows;
-            BlueDataUtility.compute_differences_fast(new_state, old_dp.newRows, out del_rows, out added_rows);
-            dp = new DataPacket(new_state, added_rows, del_rows);
-         }
-         if (dp.addedRows.Count == 0 && dp.deletedRows.Count == 0)
-            return;
-         myFireEvent(dp);
-      }
-
-      public void doWork() {
-         if (_dirty && DateTime.Now - _last_poll_time > _poll_period) {
-            _last_poll_time = DateTime.Now;
-            _dirty = false;
-            _scan();
-         }
-      }
-   }
-}
+namespace BCG {
+   using BCG.Utilities.General;
+
+   using bts.api;
+   using bts.api.domain;
+   using bts.api.synthetic;
+   using bts.md;
+   using bts.spark;
+   using bts.utils;
+
+   using mbts;
+   using mbts.co2;
+   using mbts.config;
+   using mbts.spark;
+   using mbts.ui;
+
+   using Spark.Core.Data;
+   using Spark.Core.Disposables;
+   using Spark.Core.Reactive;
+
+   using System;
+   using System.Collections.Concurrent;
+   using System.Collections.Generic;
+   using System.Collections.ObjectModel;
+   using System.Linq;
+   using System.Reactive.Linq;
+   using bts.api.core;
+   using Spark.Api.MarketData;
+
+   using SecurityKey = System.UInt32;
+   using System.Data;
+   using System.Reflection.Metadata;
+
+   [DataStreamUserRespresentation("price_stats")]
+   public class PriceStatsStream : ViewStream, IWorker {
+      private readonly TimeSpan _poll_period = TimeSpan.FromMilliseconds(500);
+      private DateTime _last_poll_time = DateTime.MinValue;
+      private ViewStreamDatabase _vsd;
+      private int _id = 0;
+      IReadOnlyDictionary<SecurityKey, PriceStats> _cached_state = null;
+      MarketDataClient _md_client;
+      private bool _dirty = false;
+      private readonly IBlueTableSchema _pstats_scheam = BlueDataUtility.form_schema("bbo",
+                                                Tuple.Create("id", TypeCode.Int32),
+                                                Tuple.Create("sec_key", TypeCode.Int32),
+                                                Tuple.Create("sec", TypeCode.String),
+                                                Tuple.Create("open", TypeCode.UInt32),
+                                                Tuple.Create("close", TypeCode.Double),
+                                                Tuple.Create("settlement", TypeCode.Single));
+      IDisposable? subscription;
+
+      // TODO: add cons for symbol, exchange etc 
+      public PriceStatsStream()
+      : this(ViewStreamDatabase.instance) {
+      }
+
+      public PriceStatsStream(ViewStreamDatabase vsd) {
+         bts.Log.Gen.info("PriceStatsStream.cons");
+         _vsd = vsd;
+         _md_client = new MarketDataClient(new MDSource(TimeSpan.FromSeconds(0.5)));
+      }
+
+      protected override void myOnFirstSubscriber() {
+         _vsd.addWorker(this);
+         subscription = _md_client.price_stats().Subscribe(_on_price_stats);
+      }
+
+      private void _log_updates(TableUpdate<PriceStats, uint> update) {
+         int i = 0;
+         // foreach (BookTuple bt in update.added) {
+         //    bts.Log.Gen.info($"PriceStatsStream added: idx: {i++} bid: {bt.book.bids[0].price} / {bt.book.bids[0].size} ask: {bt.book.asks[0].price} / {bt.book.asks[0].size}");
+         // }
+         // foreach (Change<BookTuple> c in update.changes) {
+         //    var bt = c.New;
+         //    bts.Log.Gen.info($"PriceStatsStream changes: idx: {i} bid: {bt.book.bids[0].price} / {bt.book.bids[0].size} ask: {bt.book.asks[0].price} / {bt.book.asks[0].size}");
+         // }
+      }
+
+      private void _on_price_stats(TableUpdate<PriceStats, uint> update) {
+         _log_updates(update);
+         // just cacching in here, will populate the rows in _poll_scan and fire the datapacket
+         bts.Log.Gen.info($"PriceStatsStream._on_price_stats state: {update.state.Count()} changes: {update.changes.Count()} added: {update.added.Count()}");
+         _cached_state = update.state;
+         _dirty = true;
+      }
+
+      protected override void myOnLastSubscriber() {
+         _vsd.removeWorker(this);
+         Disposable.dispose(ref subscription);
+      }
+
+      private void _scan() {
+         // this shouldn be made incremental using the TableUpdate
+         bts.Log.Gen.info("PriceStatsStream._scan_bbo");
+         if (_cached_state == null)
+            return;
+         BlueTable new_state = new BlueTable(_pstats_scheam);
+         foreach (var kv in _cached_state) {
+            SecurityKey skey = kv.Key;
+            int id = Convert.ToInt32(skey);
+            PriceStats pstats = kv.Value;
+            IBlueRow r = new BlueRow(_pstats_scheam, id, skey, pstats.security.ToString(), pstats.open, pstats.close, pstats.settlement);
+            new_state.addRow(r);
+         }
+         DataPacket dp = null;
+         if (myLastValue == null) {
+            dp = new DataPacket(new_state, new_state, new BlueTable(_pstats_scheam));
+         } else {
+            DataPacket old_dp = myLastValue as DataPacket;
+            IBlueRowCollection added_rows, del_rows;
+            BlueDataUtility.compute_differences_fast(new_state, old_dp.newRows, out del_rows, out added_rows);
+            dp = new DataPacket(new_state, added_rows, del_rows);
+         }
+         if (dp.addedRows.Count == 0 && dp.deletedRows.Count == 0)
+            return;
+         myFireEvent(dp);
+      }
+
+      public void doWork() {
+         if (_dirty && DateTime.Now - _last_poll_time > _poll_period) {
+            _last_poll_time = DateTime.Now;
+            _dirty = false;
+            _scan();
+         }
+      }
+   }
+}

src/DataStreamSuite/TransportUtilities/TransportUtilities.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFramework>net7.0</TargetFramework>
+    <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
   </PropertyGroup>

src/client/Spark.Console/Spark.Console.csproj

@@ -4,7 +4,7 @@
     <OutputType>Exe</OutputType>
     <TargetFrameworks>net8.0</TargetFrameworks>
     <Nullable>enable</Nullable>
-    <RuntimeIdentifiers>win10-x64;ubuntu.16.04-x64</RuntimeIdentifiers>
+    <RuntimeIdentifiers>any</RuntimeIdentifiers>
     <Authors>Blue Trading Systems</Authors>
     <Company>Blue Trading Systems</Company>
     <Product>Spark</Product>

src/client/Spark.Console/src/Program.cs

@@ -1,45 +1,45 @@
-namespace Spark.Console {
-   using bts;
-   using bts.utils;
-
-   using System;
-
-   using CommandLine;
-
-   class Program {
-      static int Main(string[] args) {
-         // Initializing config is up to each individual command
-         // We call provide_command_line here in case config is first
-         // initialized from c++ instead of c#
-         BTSNativeMethods.provide_command_line(args, args.Length);
-
-         var parser = new Parser(ps => {
-            ps.CaseInsensitiveEnumValues = true;
-            ps.HelpWriter = Console.Out;
-         });
-
-         // Note: this can be made to infer the options type list from the list of delegates
-         return parser.parse_and_run<
-            ConfigCommandOptions,
-            ScriptCommandOptions,
-            TailServiceOptions,
-            TestServiceOptions,
-            SettingsCommandOptions,
-            TestCommandOptions,
-            OrderStressOptions,
-            MBOCommandOptions,
-            int
-         >(
-            BTS.remove_config_arg(args),
-            ConfigCommand.run,
-            ScriptCommand.run,
-            TailService.run,
-            TestService.run,
-            SettingsCommand.run,
-            TestCommand.run,
-            OrderStressCommand.run,
-            MBOCommand.run,
-            errors => 1);
-      }
-   }
-}
+namespace Spark.Console {
+   using bts;
+   using bts.utils;
+
+   using System;
+
+   using CommandLine;
+
+   class Program {
+      static int Main(string[] args) {
+         // Initializing config is up to each individual command
+         // We call provide_command_line here in case config is first
+         // initialized from c++ instead of c#
+         BTSNativeMethods.provide_command_line(args, args.Length);
+
+         var parser = new Parser(ps => {
+            ps.CaseInsensitiveEnumValues = true;
+            ps.HelpWriter = Console.Out;
+         });
+
+         // Note: this can be made to infer the options type list from the list of delegates
+         return parser.parse_and_run<
+            ConfigCommandOptions,
+            ScriptCommandOptions,
+            TailServiceOptions,
+            TestServiceOptions,
+            SettingsCommandOptions,
+            TestCommandOptions,
+            OrderStressOptions,
+            MBOCommandOptions,
+            int
+         >(
+            args,
+            ConfigCommand.run,
+            ScriptCommand.run,
+            TailService.run,
+            TestService.run,
+            SettingsCommand.run,
+            TestCommand.run,
+            OrderStressCommand.run,
+            MBOCommand.run,
+            errors => 1);
+      }
+   }
+}

src/client/spark/Spark.csproj

@@ -11,7 +11,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <Configurations>Debug;Release</Configurations>
     <Platforms>x64</Platforms>
-    <RuntimeIdentifiers>win10-x64</RuntimeIdentifiers>
+    <RuntimeIdentifiers>win-x64</RuntimeIdentifiers>
     <PlatformTarget>x64</PlatformTarget>
     <LanguageTargets Condition="'$(VisualStudioVersion)'=='17.0'">
       C:/Program Files/Microsoft Visual Studio/2022/Community/Msbuild/Current/Bin/amd64/Microsoft.CSharp.targets

src/client/spark/view/Controls/DIYGrid/CellRender/CellRender.cs

@@ -70,8 +70,7 @@ namespace mbts.ui.controls {
             public double border_thickness => _border_thickness.Value;
 
             void _apply_animation() {
-               var bga = _animations.OfType<BackgroundAnimation>().FirstOrDefault();
-               if (bga != null) {
+               if (_animations.Select(a => a.background_animation).ExceptNull().TryGetFirst(out var bga)) {
                   _background.set(bga.brush);
                   if (bga.pen != null) {
                      _border.set(bga.pen.Brush);

src/client/spark_api/MarketData/MarketDataClient.cs

@@ -1,287 +1,280 @@
-#nullable enable
-namespace bts.md {
-   using bts.api;
-   using bts.api.core;
-   using bts.collections;
-
-   using mbts;
-   using mbts.co2;
-   using mbts.spark;
-
-   using Spark.Api.MarketData;
-   using Spark.Core;
-   using Spark.Core.Reactive;
-
-   using System;
-   using System.Collections.Generic;
-   using System.Linq;
-   using System.Reactive.Linq;
-
-   public class MarketDataClient {
-      readonly MDSource _source;
-      readonly TimeSpan _poll_interval;
-      readonly TimeSpan _slow_poll_interval;
-      readonly uint _num_depth_levels;
-
-      public MarketDataClient(MDSource source)
-         : this(source, 5, TimeSpan.FromSeconds(0.1), TimeSpan.FromSeconds(1)) { }
-
-      public MarketDataClient(
-         MDSource source,
-         uint num_depth_levels,
-         TimeSpan poll_interval,
-         TimeSpan slow_poll_interval) {
-         _source = source;
-         _poll_interval = poll_interval;
-         if (slow_poll_interval < poll_interval) {
-            Log.Api.warn("MarketDataClient 'slow_poll_interval' smaller than 'poll_interval'");
-         }
-         _slow_poll_interval = slow_poll_interval;
-         _num_depth_levels = num_depth_levels;
-      }
-
-      public IObservable<IReadOnlyDictionary<uint, SecurityImmutable>> securities(
-         SecurityCriteria? criteria = null) =>
-         criteria.subscribe(_source.subscribe_securities())
-            .Select(secs => secs.ToDictionary(s => s.Id));
-
-      public IObservable<TableUpdate<SecurityImmutable, uint>> securities_incremental(
-         SecurityCriteria? criteria = null) =>
-         criteria is null ? securities_incremental() : securities_incremental(criteria.includes);
-
-      public IObservable<TableUpdate<SecurityImmutable, uint>> securities_incremental(
-         Func<SecurityImmutable, bool> filter) {
-         var secs_src = _source.subscribe_securities().ToSelector(
-            sec_mds => MappedDictionary.create(sec_mds, s => s.security));
-         if (filter is not null) {
-            secs_src = secs_src.extend(
-               secs => new FilteredDictionary<uint, SecurityImmutable>(secs, filter));
-         }
-         return secs_src.Table(s => s.Id);
-      }
-
-      public IObservable<TableUpdate<BookTuple, uint>> books(SecurityCriteria? criteria = null) =>
-         books(criteria is null ? null :
-            new Func<SecurityImmutable, bool>(s => criteria.includes(s)));
-
-      public IObservable<TableUpdate<BookTuple, uint>> books(Func<SecurityImmutable, bool>? filter) {
-         // This MDSource's IObservable provides callbacks when a security is added or removed, but
-         // doesn't detect book changes. To avoid maintaining complicated state, create a brand new
-         // IObservable of book updates whenever the securities change.
-         var secs = _source.subscribe_securities();
-         var filtered_secs = filter is null ?
-            secs.Select(mds => mds.Values) :
-            secs.Select(mds => mds.Values.Where(md => filter(md.security)));
-         return filtered_secs.Select(fixed_sec_market_data).FlattenTableSeries();
-
-         IObservable<TableUpdate<BookTuple, uint>> fixed_sec_market_data(
-            IEnumerable<SecurityMD> security_mds) {
-            // Convert 'security_mds' to a list of PollableBooks.
-            var cached_books = security_mds
-               .Select(s => new PollableBook(s, _num_depth_levels))
-               .ToList();
-
-            return Observable.Interval(_poll_interval).Scan(
-               TableUpdate<BookTuple, uint>.mk_empty(get_sec_id),
-               poll_books);
-
-            uint get_sec_id(BookTuple book) =>
-               book.security.Id;
-
-            TableUpdate<BookTuple, uint> poll_books(TableUpdate<BookTuple, uint> table, long _) {
-               var bd = table.to_builder();
-               foreach (var cbook in cached_books) {
-                  if (cbook.poll_changes()) {
-                     bd.add_or_update(cbook.to_book_tuple());
-                  }
-               }
-               return bd.to_table();
-            }
-         }
-      }
-
-      public IObservable<IList<TradeInfo>> trades(TradesSubscriptionFilter filter) {
-         var sec_mds = filter.security_criteria == null ?
-            _source.subscribe_securities() :
-            filter.security_criteria.subscribe_md_map(_source.subscribe_securities());
-         return TradesSource.create(_source.consumer, sec_mds, _poll_interval);
-      }
-
-      public IObservable<TableUpdate<PriceTicker, uint>> price_ticker(
-         SecurityCriteria? criteria = null) {
-         // This MDSource's IObservable provides callbacks when a security is added or removed, but
-         // doesn't detect ticker changes. To avoid maintaining complicated state, create a brand new
-         // IObservable of ticker updates whenever the securities change.
-         return criteria.subscribe_md(_source.subscribe_securities())
-            .Select(fixed_sec_price_tickers)
-            .FlattenTableSeries();
-
-         IObservable<TableUpdate<PriceTicker, uint>> fixed_sec_price_tickers(
-            IEnumerable<SecurityMD> security_mds) {
-            // Convert 'security_mds' to a list of PollablePriceTickers.
-            var cached_tickers = security_mds
-               .Select(s => new PollablePriceTicker(s))
-               .ToList();
-
-            return Observable.Interval(_poll_interval).Scan(
-               TableUpdate<PriceTicker, uint>.mk_empty(get_sec_id),
-               poll_tickers);
-
-            uint get_sec_id(PriceTicker ticker) =>
-               ticker.security.Id;
-
-            TableUpdate<PriceTicker, uint> poll_tickers(TableUpdate<PriceTicker, uint> table, long _) {
-               var bd = table.to_builder();
-               foreach (var cticker in cached_tickers) {
-                  if (cticker.poll_changes()) {
-                     bd.add_or_update(cticker.to_ticker());
-                  }
-               }
-               return bd.to_table();
-            }
-         }
-      }
-
-      public IObservable<TableUpdate<PriceStats, uint>> price_stats(
-         SecurityCriteria? criteria = null) {
-         // This MDSource's IObservable provides callbacks when a security is added or removed, but
-         // doesn't detect stats changes. To avoid maintaining complicated state, create a brand new
-         // IObservable of stats updates whenever the securities change.
-         return criteria.subscribe_md(_source.subscribe_securities())
-            .Select(fixed_sec_price_stats)
-            .FlattenTableSeries();
-
-         IObservable<TableUpdate<PriceStats, uint>> fixed_sec_price_stats(
-            IEnumerable<SecurityMD> security_mds) {
-            // Convert 'security_mds' to a list of PollablePriceStats.
-            List<PollablePriceStats>? cached_statss = security_mds
-               .Select(s => new PollablePriceStats(s))
-               .ToList();
-            var seed = TableUpdate<PriceStats, uint>.mk_empty(get_sec_id);
-            seed = get_seed(seed);
-            return Observable.Interval(_slow_poll_interval).Scan(
-                  seed,
-               poll_stats);
-
-            uint get_sec_id(PriceStats stats) =>
-               stats.security.Id;
-            TableUpdate<PriceStats, uint> get_seed(TableUpdate<PriceStats, uint> table) {
-               if (cached_statss == null) {
-                  return table;
-               }
-               var bd = table.to_builder();
-               foreach (var cstats in cached_statss) {
-                  bd.add_or_update(cstats.to_stats());
-               }
-               return bd.to_table();
-            }
-            TableUpdate<PriceStats, uint> poll_stats(TableUpdate<PriceStats, uint> table, long _) {
-               var bd = table.to_builder();
-               foreach (var cstats in cached_statss) {
-                  if (cstats.poll_changes()) {
-                     bd.add_or_update(cstats.to_stats());
-                  }
-               }
-               return bd.to_table();
-            }
-         }
-      }
-
-      class PollableBook {
-         readonly SecurityMD _security_md;
-         readonly uint _num_depth_levels;
-         ulong _last_update_time = 0;
-         // Reuse the same arrays as an optimization to avoid reallocating memory on each poll.
-         // Note: this will break if the code isn't called in a thread-safe manner.
-         NativePriceSize[] _bids;
-         NativePriceSize[] _asks;
-
-         public PollableBook(SecurityMD security_md, uint num_depth_levels) {
-            _security_md = security_md;
-            _num_depth_levels = num_depth_levels;
-            _bids = new NativePriceSize[_num_depth_levels];
-            _asks = new NativePriceSize[_num_depth_levels];
-         }
-
-         public BookTuple to_book_tuple() {
-            var book = new Book(
-               _security_md.security.Id, _to_book_side(_bids), _to_book_side(_asks));
-            return new(_security_md.security, book, _security_md.quantity_display);
-         }
-
-         public bool poll_changes() =>
-            _security_md.md.get_depth(
-               ref _last_update_time, ref _bids, ref _asks, _num_depth_levels);
-
-         static List<PriceSize> _to_book_side(NativePriceSize[] native_book_side) =>
-            native_book_side
-               .Select(nps => new PriceSize(nps.size, nps.direct_size, nps.implied_size, nps.price))
-               .ToList();
-      }
-
-      class PollablePriceTicker {
-         readonly SecurityMD _security_md;
-         ulong _bbo_poll_time = 0;
-         ulong _last_poll_time = 0;
-         NativePriceSize _bid;
-         NativePriceSize _ask;
-         NativePriceSize _last;
-         PriceTicker _ticker;
-         ulong _volume;
-
-         public PollablePriceTicker(SecurityMD security_md) =>
-            _security_md = security_md;
-
-         public PriceTicker to_ticker() =>
-            _ticker;
-
-         public bool poll_changes() {
-            var md = _security_md.md;
-            md.get_bbo(ref _bbo_poll_time, out _bid, out _ask);
-            md.get_last_trade(ref _last_poll_time, out _last, out _, out _volume);
-            return Swap.toggle_to(ref _ticker, _mk_ticker());
-         }
-
-         PriceTicker _mk_ticker() {
-            var md = _security_md.md;
-            return new(
-               _security_md.security,
-               _security_md.quantity_display,
-               md.session_high,
-               md.session_low,
-               _volume,
-               _bid.price,
-               _bid.size,
-               _ask.price,
-               _ask.size,
-               md.fixing_price,
-               _last.price,
-               _last.size);
-         }
-      }
-
-      class PollablePriceStats {
-         readonly SecurityMD _security_md;
-         PriceStats _stats;
-
-         public PollablePriceStats(SecurityMD security_md) {
-            _security_md = security_md;
-            _stats = _mk_stats();
-         }
-
-         public PriceStats to_stats() =>
-            _stats;
-
-         public bool poll_changes() =>
-            Swap.toggle_to(ref _stats, _mk_stats());
-         PriceStats _mk_stats() {
-            var md = _security_md.md;
-            return new(
-               _security_md.security,
-               md.open_price,
-               md.close_price,
-               md.settlement_price);
-         }
-      }
-   }
-}
+#nullable enable
+namespace bts.md {
+   using bts.api;
+   using bts.api.core;
+   using bts.collections;
+   using bts.utils;
+
+   using mbts;
+   using mbts.co2;
+   using mbts.spark;
+
+   using Spark.Api.MarketData;
+   using Spark.Core;
+   using Spark.Core.Reactive;
+
+   using System;
+   using System.Collections.Generic;
+   using System.Linq;
+   using System.Reactive.Linq;
+
+   public class MarketDataClient {
+      readonly MDSource _source;
+      readonly TimeSpan _poll_interval;
+      readonly TimeSpan _slow_poll_interval;
+      readonly uint _num_depth_levels;
+
+      public MarketDataClient(MDSource source)
+         : this(source, 5, TimeSpan.FromSeconds(0.1), TimeSpan.FromSeconds(1)) { }
+
+      public MarketDataClient(
+         MDSource source,
+         uint num_depth_levels,
+         TimeSpan poll_interval,
+         TimeSpan slow_poll_interval) {
+         _source = source;
+         _poll_interval = poll_interval;
+         if (slow_poll_interval < poll_interval) {
+            Log.Api.warn("MarketDataClient 'slow_poll_interval' smaller than 'poll_interval'");
+         }
+         _slow_poll_interval = slow_poll_interval;
+         _num_depth_levels = num_depth_levels;
+      }
+
+      public IObservable<IReadOnlyDictionary<uint, SecurityImmutable>> securities(
+         SecurityCriteria? criteria = null) =>
+         criteria.subscribe(_source.subscribe_securities())
+            .Select(secs => secs.ToDictionary(s => s.Id));
+
+      public IObservable<TableUpdate<SecurityImmutable, uint>> securities_incremental(
+         SecurityCriteria? criteria = null) =>
+         criteria is null ? securities_incremental() : securities_incremental(criteria.includes);
+
+      public IObservable<TableUpdate<SecurityImmutable, uint>> securities_incremental(
+         Func<SecurityImmutable, bool> filter) {
+         var secs_src = _source.subscribe_securities().ToSelector(
+            sec_mds => MappedDictionary.create(sec_mds, s => s.security));
+         if (filter is not null) {
+            secs_src = secs_src.extend(
+               secs => new FilteredDictionary<uint, SecurityImmutable>(secs, filter));
+         }
+         return secs_src.Table(s => s.Id);
+      }
+
+      public IObservable<TableUpdate<BookTuple, uint>> books(SecurityCriteria? criteria = null) =>
+         books(criteria is null ? null :
+            new Func<SecurityImmutable, bool>(s => criteria.includes(s)));
+
+      public IObservable<TableUpdate<BookTuple, uint>> books(Func<SecurityImmutable, bool>? filter) {
+         // This MDSource's IObservable provides callbacks when a security is added or removed, but
+         // doesn't detect book changes. To avoid maintaining complicated state, create a brand new
+         // IObservable of book updates whenever the securities change.
+         var secs = _source.subscribe_securities();
+         var filtered_secs = filter is null ?
+            secs.Select(mds => mds.Values) :
+            secs.Select(mds => mds.Values.Where(md => filter(md.security)));
+         return filtered_secs.Select(fixed_sec_market_data).FlattenTableSeries();
+
+         IObservable<TableUpdate<BookTuple, uint>> fixed_sec_market_data(
+            IEnumerable<SecurityMD> security_mds) {
+            // Convert 'security_mds' to a list of PollableBooks.
+            var cached_books = security_mds
+               .Select(s => new PollableBook(s, _num_depth_levels))
+               .ToList();
+
+            return Observable.Interval(_poll_interval).Scan(
+               TableUpdate<BookTuple, uint>.mk_empty(get_sec_id),
+               poll_books);
+
+            uint get_sec_id(BookTuple book) =>
+               book.security.Id;
+
+            TableUpdate<BookTuple, uint> poll_books(TableUpdate<BookTuple, uint> table, long _) {
+               var bd = table.to_builder();
+               foreach (var cbook in cached_books) {
+                  if (cbook.poll_changes()) {
+                     bd.add_or_update(cbook.to_book_tuple());
+                  }
+               }
+               return bd.to_table();
+            }
+         }
+      }
+
+      public IObservable<IList<TradeInfo>> trades(TradesSubscriptionFilter filter) {
+         var sec_mds = filter.security_criteria == null ?
+            _source.subscribe_securities() :
+            filter.security_criteria.subscribe_md_map(_source.subscribe_securities());
+         return TradesSource.create(_source.consumer, sec_mds, _poll_interval);
+      }
+
+      public IObservable<TableUpdate<PriceTicker, uint>> price_ticker(
+         SecurityCriteria? criteria = null) {
+         // This MDSource's IObservable provides callbacks when a security is added or removed, but
+         // doesn't detect ticker changes. To avoid maintaining complicated state, create a brand new
+         // IObservable of ticker updates whenever the securities change.
+         return criteria.subscribe_md(_source.subscribe_securities())
+            .Select(fixed_sec_price_tickers)
+            .FlattenTableSeries();
+
+         IObservable<TableUpdate<PriceTicker, uint>> fixed_sec_price_tickers(
+            IEnumerable<SecurityMD> security_mds) {
+            // Convert 'security_mds' to a list of PollablePriceTickers.
+            var cached_tickers = security_mds
+               .Select(s => new PollablePriceTicker(s))
+               .ToList();
+
+            return Observable.Interval(_poll_interval).Scan(
+               TableUpdate<PriceTicker, uint>.mk_empty(get_sec_id),
+               poll_tickers);
+
+            uint get_sec_id(PriceTicker ticker) =>
+               ticker.security.Id;
+
+            TableUpdate<PriceTicker, uint> poll_tickers(TableUpdate<PriceTicker, uint> table, long _) {
+               bool is_first_update = table.state.Count == 0;
+               var bd = table.to_builder();
+               foreach (var cticker in cached_tickers) {
+                  if (cticker.poll_changes() || is_first_update) {
+                     bd.add_or_update(cticker.to_ticker());
+                  }
+               }
+               return bd.to_table();
+            }
+         }
+      }
+
+      public IObservable<TableUpdate<PriceStats, uint>> price_stats(
+         SecurityCriteria? criteria = null) {
+         // This MDSource's IObservable provides callbacks when a security is added or removed, but
+         // doesn't detect stats changes. To avoid maintaining complicated state, create a brand new
+         // IObservable of stats updates whenever the securities change.
+         return criteria.subscribe_md(_source.subscribe_securities())
+            .Select(fixed_sec_price_stats)
+            .FlattenTableSeries();
+
+         IObservable<TableUpdate<PriceStats, uint>> fixed_sec_price_stats(
+            IEnumerable<SecurityMD> security_mds) {
+            // Convert 'security_mds' to a list of PollablePriceStats.
+            var cached_statss = security_mds
+               .Select(s => new PollablePriceStats(s))
+               .ToList();
+
+            return Observable.Interval(_slow_poll_interval).Scan(
+               TableUpdate<PriceStats, uint>.mk_empty(get_sec_id),
+               poll_stats);
+
+            uint get_sec_id(PriceStats stats) =>
+               stats.security.Id;
+
+            TableUpdate<PriceStats, uint> poll_stats(TableUpdate<PriceStats, uint> table, long _) {
+               bool is_first_update = table.state.Count == 0;
+               var bd = table.to_builder();
+               foreach (var cstats in cached_statss) {
+                  if (cstats.poll_changes() || is_first_update) {
+                     bd.add_or_update(cstats.to_stats());
+                  }
+               }
+               return bd.to_table();
+            }
+         }
+      }
+
+      class PollableBook {
+         readonly SecurityMD _security_md;
+         readonly uint _num_depth_levels;
+         ulong _last_update_time = 0;
+         // Reuse the same arrays as an optimization to avoid reallocating memory on each poll.
+         // Note: this will break if the code isn't called in a thread-safe manner.
+         NativePriceSize[] _bids;
+         NativePriceSize[] _asks;
+
+         public PollableBook(SecurityMD security_md, uint num_depth_levels) {
+            _security_md = security_md;
+            _num_depth_levels = num_depth_levels;
+            _bids = new NativePriceSize[_num_depth_levels];
+            _asks = new NativePriceSize[_num_depth_levels];
+         }
+
+         public BookTuple to_book_tuple() {
+            var book = new Book(
+               _security_md.security.Id, _to_book_side(_bids), _to_book_side(_asks));
+            return new(_security_md.security, book, _security_md.quantity_display);
+         }
+
+         public bool poll_changes() =>
+            _security_md.md.get_depth(
+               ref _last_update_time, ref _bids, ref _asks, _num_depth_levels);
+
+         static List<PriceSize> _to_book_side(NativePriceSize[] native_book_side) =>
+            native_book_side
+               .Select(nps => new PriceSize(nps.size, nps.direct_size, nps.implied_size, nps.price))
+               .ToList();
+      }
+
+      class PollablePriceTicker {
+         readonly SecurityMD _security_md;
+         ulong _bbo_poll_time = 0;
+         ulong _last_poll_time = 0;
+         NativePriceSize _bid;
+         NativePriceSize _ask;
+         NativePriceSize _last;
+         PriceTicker _ticker;
+         ulong _volume;
+
+         public PollablePriceTicker(SecurityMD security_md) =>
+            _security_md = security_md;
+
+         public PriceTicker to_ticker() =>
+            _ticker;
+
+         public bool poll_changes() {
+            var md = _security_md.md;
+            md.get_bbo(ref _bbo_poll_time, out _bid, out _ask);
+            md.get_last_trade(ref _last_poll_time, out _last, out _, out _volume);
+            return Swap.toggle_to(ref _ticker, _mk_ticker());
+         }
+
+         PriceTicker _mk_ticker() {
+            var md = _security_md.md;
+            return new(
+               _security_md.security,
+               _security_md.quantity_display,
+               md.session_high,
+               md.session_low,
+               _volume,
+               _bid.price,
+               _bid.size,
+               _ask.price,
+               _ask.size,
+               md.fixing_price,
+               _last.price,
+               _last.size);
+         }
+      }
+
+      class PollablePriceStats {
+         readonly SecurityMD _security_md;
+         PriceStats _stats;
+
+         public PollablePriceStats(SecurityMD security_md) {
+            _security_md = security_md;
+            _stats = _mk_stats();
+         }
+
+         public PriceStats to_stats() =>
+            _stats;
+
+         public bool poll_changes() =>
+            Swap.toggle_to(ref _stats, _mk_stats());
+         PriceStats _mk_stats() {
+            var md = _security_md.md;
+            return new(
+               _security_md.security,
+               md.open_price,
+               md.close_price,
+               md.settlement_price);
+         }
+      }
+   }
+}

src/client/spark_api/api/ServiceContext.cs

@@ -1,110 +1,109 @@
-#nullable enable
-namespace bts.api.core {
-   using bts.api.user;
-
-   using System;
-   using System.Collections.Generic;
-   using System.Linq;
-   using System.Threading.Tasks;
-   using System.Reflection;
-
-   public sealed class ServiceContext : Spark.Api.IServiceProvider, IDisposable {
-      IntPtr _qbus;
-      AuthToken? _token;
-
-      public ServiceContext(string? config_source = null) {
-         BTS.init(config_source);
-         _qbus = ApiNativeMethods.api_create_quickbus(null, 0);
-      }
-
-      internal ServiceContext(IntPtr qbus) =>
-         _qbus = qbus;
-
-      public AuthTokenImmutable? token => _token?.immutable();
-      public UserTuple? user { get; private set; }
-      public bool is_authenticated => _token is not null;
-
-      internal IntPtr native_context => _qbus;
-
-      public static ServiceContext create(string? config_server = null) {
-         var args = Environment.GetCommandLineArgs();
-         BTS.init(config_server, args);
-         var qbus = ApiNativeMethods.api_create_quickbus(null, 0);
-         return new ServiceContext(qbus);
-      }
-
-      public T locate<T>(string qualifier = "") where T : class, IApiClient {
-         var ctr = typeof(T).GetConstructors(BindingFlags.NonPublic | BindingFlags.Instance)
-            .FirstOrDefault(ci => ci.GetParameters()
-               .SingleOrDefault()?.ParameterType == typeof(ClientChannel));
-         if (ctr is null) {
-            throw new InvalidOperationException(
-               $"Unable to find appropriate constructor for type '{typeof(T)}'");
-         }
-         ClientChannel channel = new QuickbusClientChannel(this, typeof(T).Name, qualifier);
-         return (T)ctr.Invoke(new object[] { channel });
-      }
-
-      public T GetService<T>(string? qualifier) where T : class, IApiClient =>
-         locate<T>(qualifier ?? string.Empty);
-
-      public async Task<bool> try_login(string username, string password) {
-         var res = await login(username, password);
-         return res.success;
-      }
-
-      public async Task<LoginResult> login(string username, string password) {
-         var res = await impl();
-         if (!res.success) {
-            Log.Api.error($"Login failed: for username: {username} password: {password} reason: {res.reason}");
-         }
-         return res;
-
-         async Task<LoginResult> impl() {
-            var auth_service = locate<AuthService>();
-            var result = await auth_service.authenticate_login_async(
-               new AuthenticateLoginRequest() {
-                  Login = username ?? string.Empty,
-                  Password = password ?? string.Empty
-               });
-            if (result.success) {
-               if (result.value.IsValid) {
-                  _token = result.value.Token;
-                  user = new(result.value.UserId, username);
-                  return new LoginResult(result.value.Reason, true);
-               } else {
-                  return new LoginResult(result.value.Reason);
-               }
-            } else {
-               return new LoginResult(result.error_message);
-            }
-         }
-      }
-
-      public void login(AuthTokenImmutable token) {
-         user = UserTuple.empty;
-         _token = token.CloneToMutable();
-      }
-
-      public void Dispose() {
-         if (_qbus != IntPtr.Zero) {
-            ApiNativeMethods.api_destroy_quickbus(_qbus);
-            _qbus = IntPtr.Zero;
-         }
-      }
-
-      internal ServerChannel publish<T>(T service, string service_type, string qualifier) where T : IApiServer {
-         var ch = new ServerChannel(this, service_type, qualifier ?? "");
-         ch.on_request += service.dispatch;
-         return ch;
-      }
-   }
-
-   public class LoginResult {
-      public LoginResult() { success = true; }
-      public LoginResult(string reason) { success = false; this.reason = reason; }
-      public LoginResult(string reason, bool success) { this.success = success; this.reason = reason; }
-      public bool success { get; }
-      public string? reason { get; }
-   }
-}
+#nullable enable
+namespace bts.api.core {
+   using bts.api.user;
+
+   using System;
+   using System.Collections.Generic;
+   using System.Linq;
+   using System.Threading.Tasks;
+   using System.Reflection;
+
+   public sealed class ServiceContext : Spark.Api.IServiceProvider, IDisposable {
+      IntPtr _qbus;
+      AuthToken? _token;
+
+      public ServiceContext(string? config_source = null) {
+         BTS.init(config_source);
+         _qbus = ApiNativeMethods.api_create_quickbus(null, 0);
+      }
+
+      internal ServiceContext(IntPtr qbus) =>
+         _qbus = qbus;
+
+      public AuthTokenImmutable? token => _token?.immutable();
+      public UserTuple? user { get; private set; }
+      public bool is_authenticated => _token is not null;
+
+      internal IntPtr native_context => _qbus;
+
+      public static ServiceContext create(string? config_server = null) {
+         BTS.init(config_server);
+         var qbus = ApiNativeMethods.api_create_quickbus(null, 0);
+         return new ServiceContext(qbus);
+      }
+
+      public T locate<T>(string qualifier = "") where T : class, IApiClient {
+         var ctr = typeof(T).GetConstructors(BindingFlags.NonPublic | BindingFlags.Instance)
+            .FirstOrDefault(ci => ci.GetParameters()
+               .SingleOrDefault()?.ParameterType == typeof(ClientChannel));
+         if (ctr is null) {
+            throw new InvalidOperationException(
+               $"Unable to find appropriate constructor for type '{typeof(T)}'");
+         }
+         ClientChannel channel = new QuickbusClientChannel(this, typeof(T).Name, qualifier);
+         return (T)ctr.Invoke(new object[] { channel });
+      }
+
+      public T GetService<T>(string? qualifier) where T : class, IApiClient =>
+         locate<T>(qualifier ?? string.Empty);
+
+      public async Task<bool> try_login(string username, string password) {
+         var res = await login(username, password);
+         return res.success;
+      }
+
+      public async Task<LoginResult> login(string username, string password) {
+         var res = await impl();
+         if (!res.success) {
+            Log.Api.error($"Login failed: for username: {username} password: {password} reason: {res.reason}");
+         }
+         return res;
+
+         async Task<LoginResult> impl() {
+            var auth_service = locate<AuthService>();
+            var result = await auth_service.authenticate_login_async(
+               new AuthenticateLoginRequest() {
+                  Login = username ?? string.Empty,
+                  Password = password ?? string.Empty
+               });
+            if (result.success) {
+               if (result.value.IsValid) {
+                  _token = result.value.Token;
+                  user = new(result.value.UserId, username);
+                  return new LoginResult(result.value.Reason, true);
+               } else {
+                  return new LoginResult(result.value.Reason);
+               }
+            } else {
+               return new LoginResult(result.error_message);
+            }
+         }
+      }
+
+      public void login(AuthTokenImmutable token) {
+         user = UserTuple.empty;
+         _token = token.CloneToMutable();
+      }
+
+      public void Dispose() {
+         if (_qbus != IntPtr.Zero) {
+            ApiNativeMethods.api_destroy_quickbus(_qbus);
+            _qbus = IntPtr.Zero;
+         }
+      }
+
+      internal ServerChannel publish<T>(T service, string service_type, string qualifier) where T : IApiServer {
+         var ch = new ServerChannel(this, service_type, qualifier ?? "");
+         ch.on_request += service.dispatch;
+         return ch;
+      }
+   }
+
+   public class LoginResult {
+      public LoginResult() { success = true; }
+      public LoginResult(string reason) { success = false; this.reason = reason; }
+      public LoginResult(string reason, bool success) { this.success = success; this.reason = reason; }
+      public bool success { get; }
+      public string? reason { get; }
+   }
+}

src/client/spark_api/utils/Locator.cs

@@ -1,25 +0,0 @@
-using System;
-using System.Threading.Tasks;
-using bts.api;
-using bts.api.core;
-
-namespace bts.api
-{
-   public static class Locator
-   {
-      readonly static Lazy<ServiceContext> _context = new Lazy<ServiceContext>(() => new ServiceContext(), true);      
-      public static T locate<T>(string qualifier="")  where T : class, IApiClient
-      {
-         return _context.Value.locate<T>(qualifier);
-      }
-      static public async Task<LoginResult> login(string username, string password)
-      {
-         return await _context.Value.login(username, password);
-      }
-      static public void login_with_token(AuthTokenImmutable token)
-      {
-         _context.Value.login(token);
-      }      
-      static public AuthTokenImmutable? token => _context.Value.token;
-   }
-}

src/client/spark_api_server/Program.cs

@@ -40,7 +40,7 @@
             DefaultEndPoint = "/",
             Host = "titan",
             Scheme = "http",
-            Port = "8080",
+            Port = 8080,
             KeepAliveIntervalSecs = 0.1,
          };
          sync.init(gwy);

src/client/spark_core/Json/JsonExtensions.cs

@@ -0,0 +1,134 @@
+#nullable enable
+namespace Spark.Core.Json;
+
+using Spark.Core.Disposables;
+
+using System;
+using System.Diagnostics.CodeAnalysis;
+using System.Text.Json;
+using System.Text.Json.Nodes;
+
+public static class JsonExtensions {
+   public static T As<T>(this JsonNode node) =>
+      node.GetValue<T>();
+
+   public static JsonArray AsArrayOrEmpty(this JsonNode node) =>
+      node.GetValueKind() == JsonValueKind.Array ? node.AsArray() : [];
+
+   public static TEnum AsEnum<TEnum>(this JsonNode node) where TEnum : struct, Enum {
+      var str = node.AsString();
+      return Enum.Parse<TEnum>(str);
+   }
+
+   public static string AsString(this JsonNode node) {
+      if (!node.AsValue().TryGetValue(out string? str)) {
+         throw new Exception("Failed to get string from JsonNode");
+      }
+      return str;
+   }
+
+   public static string AsStringOrEmpty(this JsonNode node) =>
+      node.GetValueKind() == JsonValueKind.String ? node.AsString() : string.Empty;
+
+   public static JsonArray GetArrayOrEmpty(this JsonObject obj, string propertyName) =>
+      obj.TryGetArray(propertyName, out var res) ? res : [];
+
+   public static T GetValue<T>(this JsonObject obj, string propertyName) =>
+      obj[propertyName]!.GetValue<T>();
+
+   public static JsonObject GetObjectOrEmpty(this JsonObject obj, string propertyName) =>
+      obj.TryGetObject(propertyName, out var res) ? res : [];
+
+   public static string GetStringOrEmpty(this JsonObject obj, string propertyName) =>
+      obj.TryGetString(propertyName, out var res) ? res : string.Empty;
+
+   public static bool ReadArray(
+      this Utf8JsonReader reader, [NotNullWhen(true)] out JsonArray? array) {
+      array = JsonSerializer.Deserialize<JsonArray>(ref reader);
+      return array is not null;
+   }
+
+   public static bool ReadObject(this Utf8JsonReader reader) {
+      return reader.Read() && reader.TokenType == JsonTokenType.StartObject;
+   }
+
+   public static bool ReadObject(this Utf8JsonReader reader, [NotNullWhen(true)] out JsonObject? obj) {
+      obj = JsonSerializer.Deserialize<JsonObject>(ref reader);
+      return obj is not null;
+   }
+
+   public static bool ReadPropertyName(
+      this Utf8JsonReader reader, [NotNullWhen(true)] out string? propertyName) {
+      if (reader.Read() && reader.TokenType == JsonTokenType.PropertyName) {
+         propertyName = reader.GetString()!;
+         return true;
+      }
+      propertyName = null;
+      return false;
+   }
+
+   public static bool ReadString(
+      this Utf8JsonReader reader, [NotNullWhen(true)] out string? str) {
+      str = JsonSerializer.Deserialize<string>(ref reader);
+      return str is not null;
+   }
+
+   public static bool TryGetArray(this JsonObject obj, string propertyName, [NotNullWhen(true)] out JsonArray? result) {
+      if (obj.TryGetPropertyValue(propertyName, out var v) && v?.GetValueKind() == JsonValueKind.Array) {
+         result = v.AsArray();
+         return true;
+      }
+      result = null;
+      return false;
+   }
+
+   public static bool TryGetObject(
+      this JsonObject obj, string propertyName, [NotNullWhen(true)] out JsonObject? result) {
+      if (obj.TryGetPropertyValue(propertyName, out var v) && v?.GetValueKind() == JsonValueKind.Object) {
+         result = v.AsObject();
+         return true;
+      }
+      result = null;
+      return false;
+   }
+
+   public static bool TryGetString(
+      this JsonObject obj, string propertyName, [NotNullWhen(true)] out string? result) {
+      if (obj.TryGetPropertyValue(propertyName, out var v) && v?.GetValueKind() == JsonValueKind.String) {
+         result = v.AsString();
+         return true;
+      }
+      result = null;
+      return false;
+   }
+
+   public static IDisposable WriteArray(this Utf8JsonWriter writer) {
+      writer.WriteStartArray();
+      return Disposable.Create(writer.WriteEndArray);
+   }
+
+   public static IDisposable WriteArray(this Utf8JsonWriter writer, string propertyName) {
+      writer.WriteStartArray(propertyName);
+      return Disposable.Create(writer.WriteEndArray);
+   }
+
+   public static void Write<T>(this Utf8JsonWriter writer, string propertyName, T node) {
+      writer.WritePropertyName(propertyName);
+      JsonSerializer.Serialize(writer, node);
+   }
+
+   public static IDisposable WriteObject(this Utf8JsonWriter writer) {
+      writer.WriteStartObject();
+      return Disposable.Create(writer.WriteEndObject);
+   }
+
+   public static IDisposable WriteObject(this Utf8JsonWriter writer, string propertyName) {
+      writer.WritePropertyName(propertyName);
+      return writer.WriteObject();
+   }
+
+   public static void WriteObject(this Utf8JsonWriter writer, string propertyName, JsonObject obj) {
+      writer.WritePropertyName(propertyName);
+      JsonSerializer.Serialize(writer, obj);
+   }
+}