.NET Workflow - Declarative State Consolidation (#759)

* Checkpoint

* Update workflows/DeepResearch.yaml

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* Comment

* Fix comment

* Update package version

* Fix nuget haxx

* Checkpoint

* Code complete

* Testing

* Message content workaround

* Add sequential flow

* Checkpoint

* Integration test project

* Checkpoint

* Checkpoint cleanup

* Complete

* Checkpoint

* Fix tests

* Comment cleanup

* Namespace

* Formatting

* Analyzer updates

* Workflow update

* Fixed!

* Update dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/DeclarativeWorkflowTest.cs

Co-authored-by: Tao Chen <taochen@microsoft.com>

* Fix build error

* Purge "immutable" set and dictionary

* Fix as task

* Collection expression

* Another

* Frozen => Readonly (perf)

* Fix

* Namespace

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>
Co-authored-by: Tao Chen <taochen@microsoft.com>

dotnet/Directory.Packages.props

@@ -37,6 +37,7 @@
     <PackageVersion Include="System.Linq.Async" Version="6.0.3" />
     <PackageVersion Include="System.Net.ServerSentEvents" Version="9.0.9" />
     <PackageVersion Include="System.Text.Json" Version="9.0.9" />
+    <PackageVersion Include="System.Collections.Immutable" Version="9.0.9" />
     <PackageVersion Include="System.Diagnostics.DiagnosticSource" Version="9.0.9" />
     <PackageVersion Include="System.Threading.Channels" Version="9.0.9" />
     <PackageVersion Include="System.Threading.Tasks.Extensions" Version="4.6.3" />

dotnet/src/Microsoft.Agents.Workflows.Declarative/DeclarativeWorkflowBuilder.cs

@@ -2,7 +2,6 @@
 
 using System;
 using System.IO;
-using System.Linq;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
 using Microsoft.Agents.Workflows.Declarative.PowerFx;
@@ -22,7 +21,7 @@ public static class DeclarativeWorkflowBuilder
     /// </summary>
     /// <typeparam name="TInput">The type of the input message</typeparam>
     /// <param name="workflowFile">The path to the workflow.</param>
-    /// <param name="options">The execution context for the workflow.</param>
+    /// <param name="options">Configuration options for workflow execution.</param>
     /// <param name="inputTransform">An optional function to transform the input message into a <see cref="ChatMessage"/>.</param>
     /// <returns></returns>
     public static Workflow<TInput> Build<TInput>(
@@ -40,7 +39,7 @@ public static class DeclarativeWorkflowBuilder
     /// </summary>
     /// <typeparam name="TInput">The type of the input message</typeparam>
     /// <param name="yamlReader">The reader that provides the workflow object model YAML.</param>
-    /// <param name="options">The execution context for the workflow.</param>
+    /// <param name="options">Configuration options for workflow execution.</param>
     /// <param name="inputTransform">An optional function to transform the input message into a <see cref="ChatMessage"/>.</param>
     /// <returns>The <see cref="Workflow"/> that corresponds with the YAML object model.</returns>
     public static Workflow<TInput> Build<TInput>(
@@ -59,18 +58,18 @@ public static class DeclarativeWorkflowBuilder
 
         string rootId = WorkflowActionVisitor.Steps.Root(workflowElement.BeginDialog?.Id.Value);
 
-        WorkflowScopes scopes = new();
-        scopes.Initialize(WrapWithBot(workflowElement), options.Configuration);
-        DeclarativeWorkflowState state = new(options.CreateRecalcEngine(), scopes);
+        WorkflowFormulaState state = new(options.CreateRecalcEngine());
+        state.Initialize(workflowElement.WrapWithBot(), options.Configuration);
         DeclarativeWorkflowExecutor<TInput> rootExecutor =
             new(rootId,
                 state,
                 message => inputTransform?.Invoke(message) ?? DefaultTransform(message));
 
         WorkflowActionVisitor visitor = new(rootExecutor, state, options);
-        WorkflowElementWalker walker = new(rootElement, visitor);
+        WorkflowElementWalker walker = new(visitor);
+        walker.Visit(rootElement);
 
-        return walker.GetWorkflow<TInput>();
+        return visitor.Complete<TInput>();
     }
 
     private static ChatMessage DefaultTransform(object message) =>
@@ -80,23 +79,4 @@ public static class DeclarativeWorkflowBuilder
                 string stringMessage => new ChatMessage(ChatRole.User, stringMessage),
                 _ => new(ChatRole.User, $"{message}")
             };
-
-    // Wrap with bot to ensure schema is set.
-    private static AdaptiveDialog WrapWithBot(AdaptiveDialog dialog)
-    {
-        BotDefinition bot
-            = new BotDefinition.Builder
-            {
-                Components =
-                    {
-                        new DialogComponent.Builder
-                        {
-                            SchemaName = dialog.HasSchemaName ? dialog.SchemaName : "default-schema",
-                            Dialog = new AdaptiveDialog.Builder(dialog),
-                        }
-                    }
-            }.Build();
-
-        return bot.Descendants().OfType<AdaptiveDialog>().First();
-    }
 }

dotnet/src/Microsoft.Agents.Workflows.Declarative/Extensions/ChatMessageExtensions.cs

@@ -141,7 +141,7 @@ internal static class ChatMessageExtensions
         }
 
         AgentMessageRole? role = null;
-        if (Enum.TryParse<AgentMessageRole>(roleValue.Value, out AgentMessageRole parsedRole))
+        if (Enum.TryParse(roleValue.Value, out AgentMessageRole parsedRole))
         {
             role = parsedRole;
         }
@@ -188,13 +188,13 @@ internal static class ChatMessageExtensions
         yield return new NamedValue(TypeSchema.Message.Fields.Id, message.MessageId.ToFormula());
         yield return new NamedValue(TypeSchema.Message.Fields.Role, message.Role.Value.ToFormula());
         yield return new NamedValue(TypeSchema.Message.Fields.Author, message.AuthorName.ToFormula());
-        yield return new NamedValue(TypeSchema.Message.Fields.Content, TableValue.NewTable(s_contentRecordType, message.GetContentRecords()));
+        yield return new NamedValue(TypeSchema.Message.Fields.Content, FormulaValue.NewTable(s_contentRecordType, message.GetContentRecords()));
         yield return new NamedValue(TypeSchema.Message.Fields.Text, message.Text.ToFormula());
         yield return new NamedValue(TypeSchema.Message.Fields.Metadata, message.AdditionalProperties.ToRecord());
     }
 
     private static IEnumerable<RecordValue> GetContentRecords(this ChatMessage message) =>
-        message.Contents.Select(content => RecordValue.NewRecordFromFields(content.GetContentFields()));
+        message.Contents.Select(content => FormulaValue.NewRecordFromFields(content.GetContentFields()));
 
     private static IEnumerable<NamedValue> GetContentFields(this AIContent content)
     {

dotnet/src/Microsoft.Agents.Workflows.Declarative/Extensions/DataValueExtensions.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System.Collections.Generic;
+using System.Dynamic;
 using System.Linq;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.PowerFx.Types;
@@ -59,13 +60,13 @@ internal static class DataValueExtensions
             null => null,
             BlankDataValue => null,
             BooleanDataValue boolValue => boolValue.Value,
-            NumberDataValue numberValue => (numberValue.Value),
-            FloatDataValue floatValue => (floatValue.Value),
-            StringDataValue stringValue => (stringValue.Value),
-            DateTimeDataValue dateTimeValue => (dateTimeValue.Value.DateTime),
+            NumberDataValue numberValue => numberValue.Value,
+            FloatDataValue floatValue => floatValue.Value,
+            StringDataValue stringValue => stringValue.Value,
+            DateTimeDataValue dateTimeValue => dateTimeValue.Value.DateTime,
             DateDataValue dateValue => dateValue.Value,
             TimeDataValue timeValue => timeValue.Value,
-            TableDataValue tableValue => tableValue.Values.Select(value => value.ToRecordValue()).ToArray(),
+            TableDataValue tableValue => tableValue.Values.Select(value => value.ToObject()).ToArray(),
             RecordDataValue recordValue => recordValue.ToDictionary(),
             OptionDataValue optionValue => optionValue.Value.Value,
             _ => throw new DeclarativeModelException($"Unsupported {nameof(DataValue)} type: {value.GetType().Name}"),
@@ -88,6 +89,19 @@ internal static class DataValueExtensions
         return recordType;
     }
 
+    public static ExpandoObject ToObject(this RecordDataValue recordDataValue)
+    {
+        ExpandoObject expandoObject = new();
+
+        IDictionary<string, object?> dictionary = expandoObject;
+        foreach (KeyValuePair<string, DataValue> field in recordDataValue.Properties)
+        {
+            dictionary[field.Key] = field.Value?.ToObject();
+        }
+
+        return expandoObject;
+    }
+
     private static RecordType ParseRecordType(this RecordDataValue record)
     {
         RecordType recordType = RecordType.Empty();

dotnet/src/Microsoft.Agents.Workflows.Declarative/Extensions/DialogBaseExtensions.cs

@@ -0,0 +1,27 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Linq;
+using Microsoft.Bot.ObjectModel;
+
+namespace Microsoft.Agents.Workflows.Declarative.Extensions;
+
+internal static class DialogBaseExtensions
+{
+    public static TDialog WrapWithBot<TDialog>(this TDialog dialog) where TDialog : DialogBase
+    {
+        BotDefinition bot
+            = new BotDefinition.Builder
+            {
+                Components =
+                    {
+                        new DialogComponent.Builder
+                        {
+                            SchemaName = dialog.HasSchemaName ? dialog.SchemaName : "default-schema",
+                            Dialog = dialog.ToBuilder(),
+                        }
+                    }
+            }.Build();
+
+        return bot.Descendants().OfType<TDialog>().First();
+    }
+}

dotnet/src/Microsoft.Agents.Workflows.Declarative/Extensions/FormulaValueExtensions.cs

@@ -8,6 +8,7 @@ using System.Dynamic;
 using System.Linq;
 using System.Text.Json;
 using System.Text.Json.Nodes;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.PowerFx.Types;
 using BlankType = Microsoft.PowerFx.Types.BlankType;
@@ -24,6 +25,7 @@ internal static class FormulaValueExtensions
         value switch
         {
             null => FormulaValue.NewBlank(),
+            UnassignedValue => FormulaValue.NewBlank(),
             FormulaValue formulaValue => formulaValue,
             bool booleanValue => FormulaValue.New(booleanValue),
             int decimalValue => FormulaValue.New(decimalValue),
@@ -142,7 +144,7 @@ internal static class FormulaValueExtensions
         TableDataValue.TableFromRecords(value.Rows.Select(row => row.Value.ToRecord()).ToImmutableArray());
 
     public static RecordDataValue ToRecord(this RecordValue value) =>
-        RecordDataValue.RecordFromFields(value.OriginalFields.Select(field => field.GetKeyValuePair()).ToImmutableArray());
+        RecordDataValue.RecordFromFields(value.OriginalFields.Select(field => field.GetKeyValuePair()));
 
     private static RecordValue ToRecord(this IDictionary value)
     {

dotnet/src/Microsoft.Agents.Workflows.Declarative/Extensions/IWorkflowContextExtensions.cs

@@ -3,7 +3,9 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
+using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.Extensions;
 
@@ -17,4 +19,21 @@ internal static class IWorkflowContextExtensions
 
     public static ValueTask SendResultMessageAsync(this IWorkflowContext context, string id, object? result = null, CancellationToken cancellationToken = default) =>
         context.SendMessageAsync(new ExecutorResultMessage(id, result));
+
+    public static ValueTask QueueStateUpdateAsync<TValue>(this IWorkflowContext context, PropertyPath variablePath, TValue? value) =>
+        context.QueueStateUpdateAsync(Throw.IfNull(variablePath.VariableName), value, Throw.IfNull(variablePath.VariableScopeName));
+
+    public static async Task<WorkflowFormulaState> GetStateAsync(this IWorkflowContext context, CancellationToken cancellationToken)
+    {
+        if (context is DeclarativeWorkflowContext declarativeContext)
+        {
+            return declarativeContext.State;
+        }
+
+        WorkflowFormulaState state = new(RecalcEngineFactory.Create());
+
+        await state.RestoreAsync(context, cancellationToken).ConfigureAwait(false);
+
+        return state;
+    }
 }

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/DeclarativeActionExecutor.cs

@@ -1,12 +1,12 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
-using System.Collections.Generic;
-using System.Collections.Immutable;
+using System.Collections.Frozen;
 using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Logging.Abstractions;
@@ -15,7 +15,7 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
 
-internal abstract class DeclarativeActionExecutor<TAction>(TAction model, DeclarativeWorkflowState state) :
+internal abstract class DeclarativeActionExecutor<TAction>(TAction model, WorkflowFormulaState state) :
     DeclarativeActionExecutor(model, state)
     where TAction : DialogAction
 {
@@ -24,16 +24,15 @@ internal abstract class DeclarativeActionExecutor<TAction>(TAction model, Declar
 
 internal abstract class DeclarativeActionExecutor : Executor<ExecutorResultMessage>
 {
-    private static readonly ImmutableHashSet<string> s_mutableScopes =
-        new HashSet<string>
-        {
-                VariableScopeNames.Topic,
-                VariableScopeNames.Global,
-        }.ToImmutableHashSet();
+    private static readonly FrozenSet<string> s_mutableScopes =
+        [
+            VariableScopeNames.Topic,
+            VariableScopeNames.Global
+        ];
 
     private string? _parentId;
 
-    protected DeclarativeActionExecutor(DialogAction model, DeclarativeWorkflowState state)
+    protected DeclarativeActionExecutor(DialogAction model, WorkflowFormulaState state)
         : base(model.Id.Value)
     {
         if (!model.HasRequiredProperties)
@@ -51,7 +50,7 @@ internal abstract class DeclarativeActionExecutor : Executor<ExecutorResultMessa
 
     internal ILogger Logger { get; set; } = NullLogger<DeclarativeActionExecutor>.Instance;
 
-    protected DeclarativeWorkflowState State { get; }
+    protected WorkflowFormulaState State { get; }
 
     protected virtual bool IsDiscreteAction => true;
 
@@ -72,7 +71,7 @@ internal abstract class DeclarativeActionExecutor : Executor<ExecutorResultMessa
 
         try
         {
-            object? result = await this.ExecuteAsync(context, cancellationToken: default).ConfigureAwait(false);
+            object? result = await this.ExecuteAsync(new DeclarativeWorkflowContext(context, this.State), cancellationToken: default).ConfigureAwait(false);
 
             if (this.EmitResultEvent)
             {
@@ -119,7 +118,7 @@ internal abstract class DeclarativeActionExecutor : Executor<ExecutorResultMessa
             throw new DeclarativeModelException($"Invalid scope: {targetPath.VariableScopeName}");
         }
 
-        await this.State.SetAsync(targetPath, result, context).ConfigureAwait(false);
+        await context.QueueStateUpdateAsync(targetPath, result).ConfigureAwait(false);
 
 #if DEBUG
         string? resultValue = result.Format();
@@ -127,7 +126,7 @@ internal abstract class DeclarativeActionExecutor : Executor<ExecutorResultMessa
         Debug.WriteLine(
             $"""
             STATE: {this.GetType().Name} [{this.Id}]
-             NAME: {targetPath.Format()}
+             NAME: {targetPath}
             VALUE:{valuePosition}{result.Format()} ({result.GetType().Name})
             """);
 #endif

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/DeclarativeWorkflowContext.cs

@@ -0,0 +1,81 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Collections.Generic;
+using System.Threading.Tasks;
+using Microsoft.Agents.Workflows.Declarative.Extensions;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
+using Microsoft.Bot.ObjectModel;
+using Microsoft.PowerFx.Types;
+
+namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
+
+internal sealed class DeclarativeWorkflowContext : IWorkflowContext
+{
+    public DeclarativeWorkflowContext(IWorkflowContext source, WorkflowFormulaState state)
+    {
+        this.Source = source;
+        this.State = state;
+    }
+
+    private IWorkflowContext Source { get; }
+    public WorkflowFormulaState State { get; }
+
+    /// <inheritdoc/>
+    public ValueTask AddEventAsync(WorkflowEvent workflowEvent) => this.Source.AddEventAsync(workflowEvent);
+
+    /// <inheritdoc/>
+    public ValueTask QueueClearScopeAsync(string? scopeName = null)
+    {
+        this.State.ResetAll(scopeName);
+        return this.Source.QueueClearScopeAsync(scopeName);
+    }
+
+    /// <inheritdoc/>
+    public async ValueTask QueueStateUpdateAsync<T>(string key, T? value, string? scopeName = null)
+    {
+        ValueTask task = value switch
+        {
+            null => QueueEmptyStateAsync(),
+            FormulaValue formulaValue => QueueFormulaStateAsync(formulaValue),
+            DataValue dataValue => QueueDataValueStateAsync(dataValue),
+            _ => QueueNativeStateAsync(value),
+        };
+
+        await task.ConfigureAwait(false);
+
+        ValueTask QueueEmptyStateAsync()
+        {
+            this.State.Set(key, FormulaValue.NewBlank(), scopeName);
+            return this.Source.QueueStateUpdateAsync(key, UnassignedValue.Instance, scopeName);
+        }
+
+        ValueTask QueueFormulaStateAsync(FormulaValue formulaValue)
+        {
+            this.State.Set(key, formulaValue, scopeName);
+            return this.Source.QueueStateUpdateAsync(key, formulaValue.ToObject(), scopeName);
+        }
+
+        ValueTask QueueDataValueStateAsync(DataValue dataValue)
+        {
+            FormulaValue formulaValue = dataValue.ToFormula();
+            this.State.Set(key, formulaValue, scopeName);
+            return this.Source.QueueStateUpdateAsync(key, formulaValue.ToObject(), scopeName);
+        }
+
+        ValueTask QueueNativeStateAsync(object? rawValue)
+        {
+            FormulaValue formulaValue = rawValue.ToFormula();
+            this.State.Set(key, formulaValue, scopeName);
+            return this.Source.QueueStateUpdateAsync(key, rawValue, scopeName);
+        }
+    }
+
+    /// <inheritdoc/>
+    public ValueTask<T?> ReadStateAsync<T>(string key, string? scopeName = null) => this.Source.ReadStateAsync<T>(key, scopeName);
+
+    /// <inheritdoc/>
+    public ValueTask<HashSet<string>> ReadStateKeysAsync(string? scopeName = null) => this.Source.ReadStateKeysAsync(scopeName);
+
+    /// <inheritdoc/>
+    public ValueTask SendMessageAsync(object message, string? targetId = null) => this.Source.SendMessageAsync(message, targetId);
+}

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/DeclarativeWorkflowExecutor.cs

@@ -12,15 +12,18 @@ namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
 /// </summary>
 internal sealed class DeclarativeWorkflowExecutor<TInput>(
     string workflowId,
-    DeclarativeWorkflowState state,
+    WorkflowFormulaState state,
     Func<TInput, ChatMessage> inputTransform) :
     Executor<TInput>(workflowId)
     where TInput : notnull
 {
     public override async ValueTask HandleAsync(TInput message, IWorkflowContext context)
     {
+        // No state to restore if we're starting from the beginning.
+        state.SetInitialized();
+
         ChatMessage input = inputTransform.Invoke(message);
-        await state.SetLastMessageAsync(context, input).ConfigureAwait(false);
+        state.SetLastMessage(input);
 
         await context.SendMessageAsync(new ExecutorResultMessage(this.Id)).ConfigureAwait(false);
     }

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/DeclarativeWorkflowModel.cs

@@ -2,8 +2,8 @@
 
 using System;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Linq;
 
 namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
 
@@ -89,7 +89,8 @@ internal sealed class DeclarativeWorkflowModel
 
     public void ConnectNodes(WorkflowBuilder workflowBuilder)
     {
-        foreach (ModelNode node in this.Nodes.Values.ToImmutableArray())
+        // Push `Values` into array to avoid modification during iteration.
+        foreach (ModelNode node in this.Nodes.Values.ToArray())
         {
             if (node.CompletionHandler is not null)
             {

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/DeclarativeWorkflowState.cs

@@ -1,103 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.Linq;
-using System.Threading;
-using System.Threading.Tasks;
-using Microsoft.Agents.Workflows.Declarative.Extensions;
-using Microsoft.Agents.Workflows.Declarative.PowerFx;
-using Microsoft.Bot.ObjectModel;
-using Microsoft.PowerFx;
-using Microsoft.PowerFx.Types;
-using Microsoft.Shared.Diagnostics;
-
-namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
-
-internal sealed class DeclarativeWorkflowState
-{
-    private static readonly ImmutableHashSet<string> s_mutableScopes =
-        new HashSet<string>
-        {
-            VariableScopeNames.Topic,
-            VariableScopeNames.Global,
-            VariableScopeNames.System,
-        }.ToImmutableHashSet();
-
-    private readonly RecalcEngine _engine;
-    private readonly WorkflowScopes _scopes;
-    private WorkflowExpressionEngine? _expressionEngine;
-    private int _isInitialized;
-
-    public DeclarativeWorkflowState(RecalcEngine engine, WorkflowScopes? scopes = null)
-    {
-        this._scopes = scopes ?? new WorkflowScopes();
-        this._engine = engine;
-        this._scopes.Bind(this._engine);
-    }
-
-    public WorkflowExpressionEngine ExpressionEngine => this._expressionEngine ??= new WorkflowExpressionEngine(this._engine);
-
-    public void Reset(PropertyPath variablePath) =>
-        this.Reset(Throw.IfNull(variablePath.VariableScopeName), Throw.IfNull(variablePath.VariableName));
-
-    public void Reset(string scopeName, string? varName = null)
-    {
-        if (string.IsNullOrWhiteSpace(varName))
-        {
-            this._scopes.Clear(scopeName);
-        }
-        else
-        {
-            this._scopes.Reset(varName, scopeName);
-        }
-
-        this._scopes.Bind(this._engine, scopeName);
-    }
-
-    public FormulaValue Get(PropertyPath variablePath) =>
-        this.Get(Throw.IfNull(variablePath.VariableScopeName), Throw.IfNull(variablePath.VariableName));
-
-    public FormulaValue Get(string scope, string varName) =>
-        this._scopes.Get(varName, scope);
-
-    public ValueTask SetAsync(PropertyPath variablePath, FormulaValue value, IWorkflowContext context) =>
-        this.SetAsync(Throw.IfNull(variablePath.VariableScopeName), Throw.IfNull(variablePath.VariableName), value, context);
-
-    public async ValueTask SetAsync(string scopeName, string varName, FormulaValue value, IWorkflowContext context)
-    {
-        if (!s_mutableScopes.Contains(scopeName))
-        {
-            throw new DeclarativeModelException($"Invalid scope: {scopeName}");
-        }
-
-        this._scopes.Set(varName, value, scopeName);
-        this._scopes.Bind(this._engine, scopeName);
-
-        await context.QueueStateUpdateAsync(varName, value.ToObject(), scopeName).ConfigureAwait(false);
-    }
-
-    public string Format(IEnumerable<TemplateLine> template) => this._engine.Format(template);
-
-    public string Format(TemplateLine? line) => this._engine.Format(line);
-
-    public async ValueTask RestoreAsync(IWorkflowContext context, CancellationToken cancellationToken)
-    {
-        if (Interlocked.CompareExchange(ref this._isInitialized, 1, 0) == 1)
-        {
-            return;
-        }
-
-        await Task.WhenAll(s_mutableScopes.Select(scopeName => ReadScopeAsync(scopeName).AsTask())).ConfigureAwait(false);
-
-        async ValueTask ReadScopeAsync(string scopeName)
-        {
-            HashSet<string> keys = await context.ReadStateKeysAsync(scopeName).ConfigureAwait(false);
-            foreach (string key in keys)
-            {
-                object? value = await context.ReadStateAsync<object>(key, scopeName).ConfigureAwait(false);
-                this._scopes.Set(key, value.ToFormula(), scopeName);
-            }
-        }
-    }
-}

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/DelegateActionExecutor.cs

@@ -4,13 +4,14 @@ using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 
 namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
 
 internal delegate ValueTask DelegateAction<TMessage>(IWorkflowContext context, TMessage message, CancellationToken cancellationToken) where TMessage : notnull;
 
-internal sealed class DelegateActionExecutor(string actionId, DelegateAction<ExecutorResultMessage>? action = null, bool emitResult = true)
-    : DelegateActionExecutor<ExecutorResultMessage>(actionId, action, emitResult)
+internal sealed class DelegateActionExecutor(string actionId, WorkflowFormulaState state, DelegateAction<ExecutorResultMessage>? action = null, bool emitResult = true)
+    : DelegateActionExecutor<ExecutorResultMessage>(actionId, state, action, emitResult)
 {
     public override ValueTask HandleAsync(ExecutorResultMessage message, IWorkflowContext context)
     {
@@ -22,12 +23,14 @@ internal sealed class DelegateActionExecutor(string actionId, DelegateAction<Exe
 
 internal class DelegateActionExecutor<TMessage> : Executor<TMessage> where TMessage : notnull
 {
+    private readonly WorkflowFormulaState _state;
     private readonly DelegateAction<TMessage>? _action;
     private readonly bool _emitResult;
 
-    public DelegateActionExecutor(string actionId, DelegateAction<TMessage>? action = null, bool emitResult = true)
+    public DelegateActionExecutor(string actionId, WorkflowFormulaState state, DelegateAction<TMessage>? action = null, bool emitResult = true)
         : base(actionId)
     {
+        this._state = state;
         this._action = action;
         this._emitResult = emitResult;
     }
@@ -36,7 +39,7 @@ internal class DelegateActionExecutor<TMessage> : Executor<TMessage> where TMess
     {
         if (this._action is not null)
         {
-            await this._action.Invoke(context, message, default).ConfigureAwait(false);
+            await this._action.Invoke(new DeclarativeWorkflowContext(context, this._state), message, default).ConfigureAwait(false);
         }
 
         if (this._emitResult)

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/WorkflowActionVisitor.cs

@@ -6,6 +6,7 @@ using System.Linq;
 using Microsoft.Agents.Workflows.Declarative.Events;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.ObjectModel;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 
 namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
@@ -24,11 +25,11 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
     private readonly WorkflowBuilder _workflowBuilder;
     private readonly DeclarativeWorkflowModel _workflowModel;
     private readonly DeclarativeWorkflowOptions _workflowOptions;
-    private readonly DeclarativeWorkflowState _workflowState;
+    private readonly WorkflowFormulaState _workflowState;
 
     public WorkflowActionVisitor(
         Executor rootAction,
-        DeclarativeWorkflowState state,
+        WorkflowFormulaState state,
         DeclarativeWorkflowOptions options)
     {
         this._workflowBuilder = new WorkflowBuilder(rootAction);
@@ -60,7 +61,7 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
             parentId = Steps.Root(parentId);
         }
 
-        this.ContinueWith(new DelegateActionExecutor(item.Id.Value), parentId, condition: null, CompletionHandler);
+        this.ContinueWith(new DelegateActionExecutor(item.Id.Value, this._workflowState), parentId, condition: null, CompletionHandler);
 
         // Complete the action scope.
         void CompletionHandler()
@@ -83,7 +84,7 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         {
             string stepId = ConditionGroupExecutor.Steps.Item(conditionGroup.Model, item);
             string parentId = GetParentId(item);
-            this._workflowModel.AddNode(new DelegateActionExecutor(stepId), parentId, CompletionHandler);
+            this._workflowModel.AddNode(new DelegateActionExecutor(stepId, this._workflowState), parentId, CompletionHandler);
 
             base.VisitConditionItem(item);
 
@@ -151,18 +152,18 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         ForeachExecutor action = new(item, this._workflowState);
         string loopId = ForeachExecutor.Steps.Next(action.Id);
         this.ContinueWith(action, condition: null, CompletionHandler); // Foreach
-        this.ContinueWith(new DelegateActionExecutor(loopId, action.TakeNextAsync), action.Id); // Loop Increment
+        this.ContinueWith(new DelegateActionExecutor(loopId, this._workflowState, action.TakeNextAsync), action.Id); // Loop Increment
         string continuationId = this.ContinuationFor(action.Id, action.ParentId); // Action continuation
         this._workflowModel.AddLink(loopId, continuationId, (_) => !action.HasValue);
 
         string startId = ForeachExecutor.Steps.Start(action.Id);
-        this._workflowModel.AddNode(new DelegateActionExecutor(startId), action.Id);
+        this._workflowModel.AddNode(new DelegateActionExecutor(startId, this._workflowState), action.Id);
         this._workflowModel.AddLink(loopId, startId, (_) => action.HasValue);
 
         void CompletionHandler()
         {
             string endActionsId = ForeachExecutor.Steps.End(action.Id); // Loop continuation
-            this.ContinueWith(new DelegateActionExecutor(endActionsId, action.ResetAsync), action.Id);
+            this.ContinueWith(new DelegateActionExecutor(endActionsId, this._workflowState, action.ResetAsync), action.Id);
             this._workflowModel.AddLink(endActionsId, loopId);
         }
     }
@@ -175,7 +176,7 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         if (loopExecutor is not null)
         {
             string parentId = GetParentId(item);
-            this.ContinueWith(new DelegateActionExecutor(item.Id.Value), parentId);
+            this.ContinueWith(new DelegateActionExecutor(item.Id.Value, this._workflowState), parentId);
             this._workflowModel.AddLink(item.Id.Value, Steps.Post(loopExecutor.Id));
             this.RestartAfter(item.Id.Value, parentId);
         }
@@ -189,7 +190,7 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         if (loopExecutor is not null)
         {
             string parentId = GetParentId(item);
-            this.ContinueWith(new DelegateActionExecutor(item.Id.Value), parentId);
+            this.ContinueWith(new DelegateActionExecutor(item.Id.Value, this._workflowState), parentId);
             this._workflowModel.AddLink(item.Id.Value, ForeachExecutor.Steps.Next(loopExecutor.Id));
             this.RestartAfter(item.Id.Value, parentId);
         }
@@ -200,7 +201,7 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         this.Trace(item);
 
         string parentId = GetParentId(item);
-        this.ContinueWith(new DelegateActionExecutor(item.Id.Value), parentId);
+        this.ContinueWith(new DelegateActionExecutor(item.Id.Value, this._workflowState), parentId);
         this.RestartAfter(item.Id.Value, parentId);
     }
 
@@ -217,7 +218,7 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         this._workflowModel.AddLink(actionId, postId, message => questionExecutor.IsComplete(message));
 
         string prepareId = QuestionExecutor.Steps.Prepare(actionId);
-        this.ContinueWith(new DelegateActionExecutor(prepareId, questionExecutor.PrepareResponseAsync, emitResult: false), parentId, message => !questionExecutor.IsComplete(message));
+        this.ContinueWith(new DelegateActionExecutor(prepareId, this._workflowState, questionExecutor.PrepareResponseAsync, emitResult: false), parentId, message => !questionExecutor.IsComplete(message));
 
         string inputId = QuestionExecutor.Steps.Input(actionId);
         InputPort inputPort = InputPort.Create<InputRequest, InputResponse>(inputId);
@@ -225,9 +226,9 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
         this._workflowModel.AddLinkFromPeer(parentId, inputId);
 
         string captureId = QuestionExecutor.Steps.Capture(actionId);
-        this.ContinueWith(new DelegateActionExecutor<InputResponse>(captureId, questionExecutor.CaptureResponseAsync, emitResult: false), parentId);
+        this.ContinueWith(new DelegateActionExecutor<InputResponse>(captureId, this._workflowState, questionExecutor.CaptureResponseAsync, emitResult: false), parentId);
 
-        this.ContinueWith(new DelegateActionExecutor(postId, questionExecutor.CompleteAsync), parentId, message => questionExecutor.IsComplete(message));
+        this.ContinueWith(new DelegateActionExecutor(postId, this._workflowState, questionExecutor.CompleteAsync), parentId, message => questionExecutor.IsComplete(message));
         this._workflowModel.AddLink(captureId, prepareId, message => !questionExecutor.IsComplete(message));
     }
 
@@ -539,12 +540,12 @@ internal sealed class WorkflowActionVisitor : DialogActionVisitor
     private string ContinuationFor(string actionId, string parentId, DelegateAction<ExecutorResultMessage>? stepAction = null)
     {
         actionId = Steps.Post(actionId);
-        this._workflowModel.AddNode(new DelegateActionExecutor(actionId, stepAction), parentId);
+        this._workflowModel.AddNode(new DelegateActionExecutor(actionId, this._workflowState, stepAction), parentId);
         return actionId;
     }
 
     private void RestartAfter(string actionId, string parentId) =>
-        this._workflowModel.AddNode(new DelegateActionExecutor($"{actionId}_Continue"), parentId);
+        this._workflowModel.AddNode(new DelegateActionExecutor($"{actionId}_Continue", this._workflowState), parentId);
 
     private static string GetParentId(BotElement item) =>
         item.GetParentId() ??

dotnet/src/Microsoft.Agents.Workflows.Declarative/Interpreter/WorkflowElementWalker.cs

@@ -6,16 +6,13 @@ namespace Microsoft.Agents.Workflows.Declarative.Interpreter;
 
 internal sealed class WorkflowElementWalker : BotElementWalker
 {
-    private readonly WorkflowActionVisitor _visitor;
+    private readonly DialogActionVisitor _visitor;
 
-    public WorkflowElementWalker(BotElement rootElement, WorkflowActionVisitor visitor)
+    public WorkflowElementWalker(DialogActionVisitor visitor)
     {
         this._visitor = visitor;
-        this.Visit(rootElement);
     }
 
-    public Workflow<TInput> GetWorkflow<TInput>() => this._visitor.Complete<TInput>();
-
     public override bool DefaultVisit(BotElement definition)
     {
         if (definition is DialogAction action)

dotnet/src/Microsoft.Agents.Workflows.Declarative/Microsoft.Agents.Workflows.Declarative.csproj

@@ -27,6 +27,7 @@
     <PackageReference Include="Microsoft.Bot.ObjectModel.Json" />
     <PackageReference Include="Microsoft.Bot.ObjectModel.PowerFx" />
     <PackageReference Include="Microsoft.PowerFx.Interpreter" />
+    <PackageReference Include="System.Collections.Immutable" />
   </ItemGroup>
 
   <ItemGroup>

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/AddConversationMessageExecutor.cs

@@ -5,19 +5,20 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Extensions.AI;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class AddConversationMessageExecutor(AddConversationMessage model, WorkflowAgentProvider agentProvider, DeclarativeWorkflowState state) :
+internal sealed class AddConversationMessageExecutor(AddConversationMessage model, WorkflowAgentProvider agentProvider, WorkflowFormulaState state) :
     DeclarativeActionExecutor<AddConversationMessage>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
         StringExpression conversationExpression = Throw.IfNull(this.Model.ConversationId, $"{nameof(this.Model)}.{nameof(this.Model.ConversationId)}");
-        string conversationId = this.State.ExpressionEngine.GetValue(conversationExpression).Value;
+        string conversationId = this.State.Evaluator.GetValue(conversationExpression).Value;
 
         ChatMessage newMessage = new(this.GetRole(), [.. this.GetContent()]) { AdditionalProperties = this.GetMetadata() };
 
@@ -32,7 +33,7 @@ internal sealed class AddConversationMessageExecutor(AddConversationMessage mode
     {
         foreach (AddConversationMessageContent content in this.Model.Content)
         {
-            AIContent? messageContent = content.Type.Value.ToContent(this.State.Format(content.Value));
+            AIContent? messageContent = content.Type.Value.ToContent(this.State.Engine.Format(content.Value));
             if (messageContent is not null)
             {
                 yield return messageContent;
@@ -47,7 +48,7 @@ internal sealed class AddConversationMessageExecutor(AddConversationMessage mode
             return ChatRole.User;
         }
 
-        AgentMessageRoleWrapper roleWrapper = this.State.ExpressionEngine.GetValue(this.Model.Role).Value;
+        AgentMessageRoleWrapper roleWrapper = this.State.Evaluator.GetValue(this.Model.Role).Value;
 
         return roleWrapper.Value.ToChatRole();
     }
@@ -59,7 +60,7 @@ internal sealed class AddConversationMessageExecutor(AddConversationMessage mode
             return null;
         }
 
-        RecordDataValue? metadataValue = this.State.ExpressionEngine.GetValue(this.Model.Metadata).Value;
+        RecordDataValue? metadataValue = this.State.Evaluator.GetValue(this.Model.Metadata).Value;
 
         return metadataValue.ToMetadata();
     }

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/ClearAllVariablesExecutor.cs

@@ -10,19 +10,19 @@ using Microsoft.Bot.ObjectModel.Abstractions;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class ClearAllVariablesExecutor(ClearAllVariables model, DeclarativeWorkflowState state)
+internal sealed class ClearAllVariablesExecutor(ClearAllVariables model, WorkflowFormulaState state)
     : DeclarativeActionExecutor<ClearAllVariables>(model, state)
 {
     protected override ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
-        EvaluationResult<VariablesToClearWrapper> variablesResult = this.State.ExpressionEngine.GetValue<VariablesToClearWrapper>(this.Model.Variables);
+        EvaluationResult<VariablesToClearWrapper> variablesResult = this.State.Evaluator.GetValue<VariablesToClearWrapper>(this.Model.Variables);
 
         variablesResult.Value.Handle(new ScopeHandler(this.Id, this.State));
 
         return default;
     }
 
-    private sealed class ScopeHandler(string executorId, DeclarativeWorkflowState state) : IEnumVariablesToClearHandler
+    private sealed class ScopeHandler(string executorId, WorkflowFormulaState state) : IEnumVariablesToClearHandler
     {
         public void HandleAllGlobalVariables()
         {
@@ -36,7 +36,7 @@ internal sealed class ClearAllVariablesExecutor(ClearAllVariables model, Declara
 
         public void HandleConversationScopedVariables()
         {
-            this.ClearAll(WorkflowScopes.DefaultScopeName);
+            this.ClearAll(WorkflowFormulaState.DefaultScopeName);
         }
 
         public void HandleUnknownValue()
@@ -51,7 +51,7 @@ internal sealed class ClearAllVariablesExecutor(ClearAllVariables model, Declara
 
         private void ClearAll(string scope)
         {
-            state.Reset(scope);
+            state.ResetAll(scope);
             Debug.WriteLine(
                 $"""
                  STATE: {this.GetType().Name} [{executorId}]

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/ConditionGroupExecutor.cs

@@ -5,6 +5,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 
@@ -27,7 +28,7 @@ internal sealed class ConditionGroupExecutor : DeclarativeActionExecutor<Conditi
         public static string Else(ConditionGroup model) => model.ElseActions.Id.Value ?? $"{model.Id}_Else";
     }
 
-    public ConditionGroupExecutor(ConditionGroup model, DeclarativeWorkflowState state)
+    public ConditionGroupExecutor(ConditionGroup model, WorkflowFormulaState state)
         : base(model, state)
     {
     }
@@ -58,7 +59,7 @@ internal sealed class ConditionGroupExecutor : DeclarativeActionExecutor<Conditi
                 continue; // Skip if no condition is defined
             }
 
-            EvaluationResult<bool> expressionResult = this.State.ExpressionEngine.GetValue(conditionItem.Condition);
+            EvaluationResult<bool> expressionResult = this.State.Evaluator.GetValue(conditionItem.Condition);
             if (expressionResult.Value)
             {
                 return Steps.Item(this.Model, conditionItem);

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/CopyConversationMessagesExecutor.cs

@@ -4,6 +4,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.Extensions.AI;
@@ -11,12 +12,12 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class CopyConversationMessagesExecutor(CopyConversationMessages model, WorkflowAgentProvider agentProvider, DeclarativeWorkflowState state) :
+internal sealed class CopyConversationMessagesExecutor(CopyConversationMessages model, WorkflowAgentProvider agentProvider, WorkflowFormulaState state) :
     DeclarativeActionExecutor<CopyConversationMessages>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
-        string conversationId = this.State.ExpressionEngine.GetValue(Throw.IfNull(this.Model.ConversationId, $"{nameof(this.Model)}.{nameof(this.Model.ConversationId)}")).Value;
+        string conversationId = this.State.Evaluator.GetValue(Throw.IfNull(this.Model.ConversationId, $"{nameof(this.Model)}.{nameof(this.Model.ConversationId)}")).Value;
         DataValue? inputMessages = this.GetInputMessages();
 
         if (inputMessages is not null)
@@ -36,7 +37,7 @@ internal sealed class CopyConversationMessagesExecutor(CopyConversationMessages
 
         if (this.Model.Messages is not null)
         {
-            EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(this.Model.Messages);
+            EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(this.Model.Messages);
             messages = expressionResult.Value;
         }
 

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/CreateConversationExecutor.cs

@@ -3,12 +3,13 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.PowerFx.Types;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class CreateConversationExecutor(CreateConversation model, WorkflowAgentProvider agentProvider, DeclarativeWorkflowState state) :
+internal sealed class CreateConversationExecutor(CreateConversation model, WorkflowAgentProvider agentProvider, WorkflowFormulaState state) :
     DeclarativeActionExecutor<CreateConversation>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/EditTableExecutor.cs

@@ -6,6 +6,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.PowerFx.Types;
@@ -13,7 +14,7 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class EditTableExecutor(EditTable model, DeclarativeWorkflowState state) : DeclarativeActionExecutor<EditTable>(model, state)
+internal sealed class EditTableExecutor(EditTable model, WorkflowFormulaState state) : DeclarativeActionExecutor<EditTable>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
@@ -22,7 +23,7 @@ internal sealed class EditTableExecutor(EditTable model, DeclarativeWorkflowStat
         FormulaValue table = this.State.Get(variablePath);
         if (table is not TableValue tableValue)
         {
-            throw this.Exception($"Require '{variablePath.Format()}' to be a table, not: '{table.GetType().Name}'.");
+            throw this.Exception($"Require '{variablePath}' to be a table, not: '{table.GetType().Name}'.");
         }
 
         TableChangeType changeType = this.Model.ChangeType.Value;
@@ -30,14 +31,14 @@ internal sealed class EditTableExecutor(EditTable model, DeclarativeWorkflowStat
         {
             case TableChangeType.Add:
                 ValueExpression addItemValue = Throw.IfNull(this.Model.Value, $"{nameof(this.Model)}.{nameof(this.Model.Value)}");
-                EvaluationResult<DataValue> addResult = this.State.ExpressionEngine.GetValue(addItemValue);
+                EvaluationResult<DataValue> addResult = this.State.Evaluator.GetValue(addItemValue);
                 RecordValue newRecord = BuildRecord(tableValue.Type.ToRecord(), addResult.Value.ToFormula());
                 await tableValue.AppendAsync(newRecord, cancellationToken).ConfigureAwait(false);
                 await this.AssignAsync(variablePath, newRecord, context).ConfigureAwait(false);
                 break;
             case TableChangeType.Remove:
                 ValueExpression removeItemValue = Throw.IfNull(this.Model.Value, $"{nameof(this.Model)}.{nameof(this.Model.Value)}");
-                EvaluationResult<DataValue> removeResult = this.State.ExpressionEngine.GetValue(removeItemValue);
+                EvaluationResult<DataValue> removeResult = this.State.Evaluator.GetValue(removeItemValue);
                 if (removeResult.Value is TableDataValue removeItemTable)
                 {
                     await tableValue.RemoveAsync(removeItemTable?.Values.Select(row => row.ToRecordValue()), all: true, cancellationToken).ConfigureAwait(false);

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/EditTableV2Executor.cs

@@ -6,6 +6,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.PowerFx.Types;
@@ -13,7 +14,7 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class EditTableV2Executor(EditTableV2 model, DeclarativeWorkflowState state) : DeclarativeActionExecutor<EditTableV2>(model, state)
+internal sealed class EditTableV2Executor(EditTableV2 model, WorkflowFormulaState state) : DeclarativeActionExecutor<EditTableV2>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
@@ -22,14 +23,14 @@ internal sealed class EditTableV2Executor(EditTableV2 model, DeclarativeWorkflow
         FormulaValue table = this.State.Get(variablePath);
         if (table is not TableValue tableValue)
         {
-            throw this.Exception($"Require '{variablePath.Format()}' to be a table, not: '{table.GetType().Name}'.");
+            throw this.Exception($"Require '{variablePath}' to be a table, not: '{table.GetType().Name}'.");
         }
 
         EditTableOperation? changeType = this.Model.ChangeType;
         if (changeType is AddItemOperation addItemOperation)
         {
             ValueExpression addItemValue = Throw.IfNull(addItemOperation.Value, $"{nameof(this.Model)}.{nameof(this.Model.ChangeType)}");
-            EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(addItemValue);
+            EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(addItemValue);
             RecordValue newRecord = BuildRecord(tableValue.Type.ToRecord(), expressionResult.Value.ToFormula());
             await tableValue.AppendAsync(newRecord, cancellationToken).ConfigureAwait(false);
             await this.AssignAsync(variablePath, newRecord, context).ConfigureAwait(false);
@@ -42,7 +43,7 @@ internal sealed class EditTableV2Executor(EditTableV2 model, DeclarativeWorkflow
         else if (changeType is RemoveItemOperation removeItemOperation)
         {
             ValueExpression removeItemValue = Throw.IfNull(removeItemOperation.Value, $"{nameof(this.Model)}.{nameof(this.Model.ChangeType)}");
-            EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(removeItemValue);
+            EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(removeItemValue);
             if (expressionResult.Value.ToFormula() is TableValue removeItemTable)
             {
                 await tableValue.RemoveAsync(removeItemTable?.Rows.Select(row => row.Value), all: true, cancellationToken).ConfigureAwait(false);

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/ForeachExecutor.cs

@@ -5,6 +5,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.PowerFx.Types;
@@ -24,7 +25,7 @@ internal sealed class ForeachExecutor : DeclarativeActionExecutor<Foreach>
     private int _index;
     private FormulaValue[] _values;
 
-    public ForeachExecutor(Foreach model, DeclarativeWorkflowState state)
+    public ForeachExecutor(Foreach model, WorkflowFormulaState state)
         : base(model, state)
     {
         this._values = [];
@@ -45,7 +46,7 @@ internal sealed class ForeachExecutor : DeclarativeActionExecutor<Foreach>
         }
         else
         {
-            EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(this.Model.Items);
+            EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(this.Model.Items);
             if (expressionResult.Value is TableDataValue tableValue)
             {
                 this._values = [.. tableValue.Values.Select(value => value.Properties.Values.First().ToFormula())];
@@ -67,11 +68,11 @@ internal sealed class ForeachExecutor : DeclarativeActionExecutor<Foreach>
         {
             FormulaValue value = this._values[this._index];
 
-            await this.State.SetAsync(Throw.IfNull(this.Model.Value), value, context).ConfigureAwait(false);
+            await context.QueueStateUpdateAsync(Throw.IfNull(this.Model.Value), value).ConfigureAwait(false);
 
             if (this.Model.Index is not null)
             {
-                await this.State.SetAsync(this.Model.Index.Path, FormulaValue.New(this._index), context).ConfigureAwait(false);
+                await context.QueueStateUpdateAsync(this.Model.Index.Path, FormulaValue.New(this._index)).ConfigureAwait(false);
             }
 
             this._index++;

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/GotoExecutor.cs

@@ -3,11 +3,12 @@
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class GotoExecutor(GotoAction model, DeclarativeWorkflowState state) :
+internal sealed class GotoExecutor(GotoAction model, WorkflowFormulaState state) :
     DeclarativeActionExecutor<GotoAction>(model, state)
 {
     protected override ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/InvokeAzureAgentExecutor.cs

@@ -15,7 +15,7 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class InvokeAzureAgentExecutor(InvokeAzureAgent model, WorkflowAgentProvider agentProvider, DeclarativeWorkflowState state) :
+internal sealed class InvokeAzureAgentExecutor(InvokeAzureAgent model, WorkflowAgentProvider agentProvider, WorkflowFormulaState state) :
     DeclarativeActionExecutor<InvokeAzureAgent>(model, state)
 {
     private AzureAgentUsage AgentUsage => Throw.IfNull(this.Model.Agent, $"{nameof(this.Model)}.{nameof(this.Model.Agent)}");
@@ -77,7 +77,7 @@ internal sealed class InvokeAzureAgentExecutor(InvokeAzureAgent model, WorkflowA
             if (assignValue is not null && conversationId is null)
             {
                 conversationId = assignValue;
-                await this.State.SetConversationIdAsync(context, conversationId).ConfigureAwait(false);
+                this.State.SetConversationId(conversationId);
                 await context.AddEventAsync(new ConversationUpdateEvent(conversationId)).ConfigureAwait(false);
             }
         }
@@ -88,7 +88,7 @@ internal sealed class InvokeAzureAgentExecutor(InvokeAzureAgent model, WorkflowA
         DataValue? userInput = null;
         if (this.AgentInput?.Messages is not null)
         {
-            EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(this.AgentInput.Messages);
+            EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(this.AgentInput.Messages);
             userInput = expressionResult.Value;
         }
 
@@ -102,12 +102,12 @@ internal sealed class InvokeAzureAgentExecutor(InvokeAzureAgent model, WorkflowA
             return null;
         }
 
-        EvaluationResult<string> conversationIdResult = this.State.ExpressionEngine.GetValue(this.Model.ConversationId);
+        EvaluationResult<string> conversationIdResult = this.State.Evaluator.GetValue(this.Model.ConversationId);
         return conversationIdResult.Value.Length == 0 ? null : conversationIdResult.Value;
     }
 
     private string GetAgentName() =>
-        this.State.ExpressionEngine.GetValue(
+        this.State.Evaluator.GetValue(
             Throw.IfNull(
                 this.AgentUsage.Name,
                 $"{nameof(this.Model)}.{nameof(this.Model.Agent)}.{nameof(this.Model.Agent.Name)}")).Value;
@@ -118,7 +118,7 @@ internal sealed class InvokeAzureAgentExecutor(InvokeAzureAgent model, WorkflowA
 
         if (this.AgentInput?.AdditionalInstructions is not null)
         {
-            additionalInstructions = this.State.Format(this.AgentInput.AdditionalInstructions);
+            additionalInstructions = this.State.Engine.Format(this.AgentInput.AdditionalInstructions);
         }
 
         return additionalInstructions;
@@ -131,7 +131,7 @@ internal sealed class InvokeAzureAgentExecutor(InvokeAzureAgent model, WorkflowA
             return true;
         }
 
-        EvaluationResult<bool> autoSendResult = this.State.ExpressionEngine.GetValue(this.AgentOutput.AutoSend);
+        EvaluationResult<bool> autoSendResult = this.State.Evaluator.GetValue(this.AgentOutput.AutoSend);
 
         return autoSendResult.Value;
     }

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/ParseValueExecutor.cs

@@ -7,6 +7,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.PowerFx.Types;
@@ -14,7 +15,7 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class ParseValueExecutor(ParseValue model, DeclarativeWorkflowState state) :
+internal sealed class ParseValueExecutor(ParseValue model, WorkflowFormulaState state) :
     DeclarativeActionExecutor<ParseValue>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
@@ -22,7 +23,7 @@ internal sealed class ParseValueExecutor(ParseValue model, DeclarativeWorkflowSt
         PropertyPath variablePath = Throw.IfNull(this.Model.Variable?.Path, $"{nameof(this.Model)}.{nameof(model.Variable)}");
         ValueExpression valueExpression = Throw.IfNull(this.Model.Value, $"{nameof(this.Model)}.{nameof(this.Model.Value)}");
 
-        EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(valueExpression);
+        EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(valueExpression);
 
         FormulaValue? parsedResult = null;
 

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/QuestionExecutor.cs

@@ -6,13 +6,14 @@ using Microsoft.Agents.Workflows.Declarative.Entities;
 using Microsoft.Agents.Workflows.Declarative.Events;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.PowerFx.Types;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class QuestionExecutor(Question model, DeclarativeWorkflowState state) :
+internal sealed class QuestionExecutor(Question model, WorkflowFormulaState state) :
     DeclarativeActionExecutor<Question>(model, state)
 {
     public static class Steps
@@ -40,16 +41,16 @@ internal sealed class QuestionExecutor(Question model, DeclarativeWorkflowState
 
         InitializablePropertyPath variable = Throw.IfNull(this.Model.Variable);
         bool hasValue = this.State.Get(variable.Path) is BlankValue;
-        bool alwaysPrompt = this.State.ExpressionEngine.GetValue(this.Model.AlwaysPrompt).Value;
+        bool alwaysPrompt = this.State.Evaluator.GetValue(this.Model.AlwaysPrompt).Value;
 
         bool proceed = !alwaysPrompt || hasValue;
         if (proceed)
         {
-            SkipQuestionMode mode = this.State.ExpressionEngine.GetValue(this.Model.SkipQuestionMode).Value;
+            SkipQuestionMode mode = this.State.Evaluator.GetValue(this.Model.SkipQuestionMode).Value;
             proceed =
                 mode switch
                 {
-                    SkipQuestionMode.SkipOnFirstExecutionIfVariableHasValue => !(await this._hasExecuted.ReadAsync(context).ConfigureAwait(false)),
+                    SkipQuestionMode.SkipOnFirstExecutionIfVariableHasValue => !await this._hasExecuted.ReadAsync(context).ConfigureAwait(false),
                     SkipQuestionMode.AlwaysSkipIfVariableHasValue => hasValue,
                     SkipQuestionMode.AlwaysAsk => true,
                     _ => true,
@@ -117,12 +118,13 @@ internal sealed class QuestionExecutor(Question model, DeclarativeWorkflowState
 
     private async ValueTask PromptAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
-        long repeatCount = this.State.ExpressionEngine.GetValue(this.Model.RepeatCount).Value;
+        long repeatCount = this.State.Evaluator.GetValue(this.Model.RepeatCount).Value;
         int actualCount = await this._promptCount.ReadAsync(context).ConfigureAwait(false);
         if (actualCount >= repeatCount)
         {
             ValueExpression defaultValueExpression = Throw.IfNull(this.Model.DefaultValue);
-            DataValue defaultValue = this.State.ExpressionEngine.GetValue(defaultValueExpression).Value;
+            DataValue defaultValue = this.State.Evaluator.GetValue(defaultValueExpression).Value;
+            await this.AssignAsync(this.Model.Variable?.Path, defaultValue.ToFormula(), context).ConfigureAwait(false);
             string defaultValueResponse = this.FormatPrompt(this.Model.DefaultValueResponse);
             await context.AddEventAsync(new MessageActivityEvent(defaultValueResponse.Trim())).ConfigureAwait(false);
             await context.SendResultMessageAsync(this.Id, result: null, cancellationToken).ConfigureAwait(false);
@@ -140,6 +142,6 @@ internal sealed class QuestionExecutor(Question model, DeclarativeWorkflowState
             return string.Empty;
         }
 
-        return this.State.Format(messageActivity.Text).Trim();
+        return this.State.Engine.Format(messageActivity.Text).Trim();
     }
 }

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/ResetVariableExecutor.cs

@@ -3,14 +3,14 @@
 using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
-using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class ResetVariableExecutor(ResetVariable model, DeclarativeWorkflowState state) :
+internal sealed class ResetVariableExecutor(ResetVariable model, WorkflowFormulaState state) :
     DeclarativeActionExecutor<ResetVariable>(model, state)
 {
     protected override ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
@@ -21,7 +21,7 @@ internal sealed class ResetVariableExecutor(ResetVariable model, DeclarativeWork
         Debug.WriteLine(
             $"""
             STATE: {this.GetType().Name} [{this.Id}]
-             NAME: {this.Model.Variable!.Format()}
+             NAME: {this.Model.Variable}
             """);
 
         return default;

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/RetrieveConversationMessageExecutor.cs

@@ -4,19 +4,20 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Extensions.AI;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class RetrieveConversationMessageExecutor(RetrieveConversationMessage model, WorkflowAgentProvider agentProvider, DeclarativeWorkflowState state) :
+internal sealed class RetrieveConversationMessageExecutor(RetrieveConversationMessage model, WorkflowAgentProvider agentProvider, WorkflowFormulaState state) :
     DeclarativeActionExecutor<RetrieveConversationMessage>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
-        string conversationId = this.State.ExpressionEngine.GetValue(Throw.IfNull(this.Model.ConversationId, $"{nameof(this.Model)}.{nameof(this.Model.ConversationId)}")).Value;
-        string messageId = this.State.ExpressionEngine.GetValue(Throw.IfNull(this.Model.MessageId, $"{nameof(this.Model)}.{nameof(this.Model.MessageId)}")).Value;
+        string conversationId = this.State.Evaluator.GetValue(Throw.IfNull(this.Model.ConversationId, $"{nameof(this.Model)}.{nameof(this.Model.ConversationId)}")).Value;
+        string messageId = this.State.Evaluator.GetValue(Throw.IfNull(this.Model.MessageId, $"{nameof(this.Model)}.{nameof(this.Model.MessageId)}")).Value;
 
         ChatMessage message = await agentProvider.GetMessageAsync(conversationId, messageId, cancellationToken).ConfigureAwait(false);
 

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/RetrieveConversationMessagesExecutor.cs

@@ -6,18 +6,19 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Extensions.AI;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class RetrieveConversationMessagesExecutor(RetrieveConversationMessages model, WorkflowAgentProvider agentProvider, DeclarativeWorkflowState state) :
+internal sealed class RetrieveConversationMessagesExecutor(RetrieveConversationMessages model, WorkflowAgentProvider agentProvider, WorkflowFormulaState state) :
     DeclarativeActionExecutor<RetrieveConversationMessages>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
-        string conversationId = this.State.ExpressionEngine.GetValue(Throw.IfNull(this.Model.ConversationId, $"{nameof(this.Model)}.{nameof(this.Model.ConversationId)}")).Value;
+        string conversationId = this.State.Evaluator.GetValue(Throw.IfNull(this.Model.ConversationId, $"{nameof(this.Model)}.{nameof(this.Model.ConversationId)}")).Value;
 
         ChatMessage[] messages = await agentProvider.GetMessagesAsync(
             conversationId,
@@ -39,7 +40,7 @@ internal sealed class RetrieveConversationMessagesExecutor(RetrieveConversationM
             return null;
         }
 
-        long limit = this.State.ExpressionEngine.GetValue(this.Model.Limit).Value;
+        long limit = this.State.Evaluator.GetValue(this.Model.Limit).Value;
         return Convert.ToInt32(Math.Min(limit, 100));
     }
 
@@ -50,7 +51,7 @@ internal sealed class RetrieveConversationMessagesExecutor(RetrieveConversationM
             return null;
         }
 
-        return this.State.ExpressionEngine.GetValue(messagExpression).Value;
+        return this.State.Evaluator.GetValue(messagExpression).Value;
     }
 
     private bool IsDescending()
@@ -60,7 +61,7 @@ internal sealed class RetrieveConversationMessagesExecutor(RetrieveConversationM
             return false;
         }
 
-        AgentMessageSortOrderWrapper sortOrderWrapper = this.State.ExpressionEngine.GetValue(this.Model.SortOrder).Value;
+        AgentMessageSortOrderWrapper sortOrderWrapper = this.State.Evaluator.GetValue(this.Model.SortOrder).Value;
 
         return sortOrderWrapper.Value == AgentMessageSortOrder.NewestFirst;
     }

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/SendActivityExecutor.cs

@@ -2,19 +2,21 @@
 
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class SendActivityExecutor(SendActivity model, DeclarativeWorkflowState state) :
+internal sealed class SendActivityExecutor(SendActivity model, WorkflowFormulaState state) :
     DeclarativeActionExecutor<SendActivity>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
     {
         if (this.Model.Activity is MessageActivityTemplate messageActivity)
         {
-            string activityText = this.State.Format(messageActivity.Text).Trim();
+            string activityText = this.State.Engine.Format(messageActivity.Text).Trim();
 
             await context.AddEventAsync(new MessageActivityEvent(activityText.Trim())).ConfigureAwait(false);
         }

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/SetMultipleVariablesExecutor.cs

@@ -4,13 +4,14 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.PowerFx.Types;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class SetMultipleVariablesExecutor(SetMultipleVariables model, DeclarativeWorkflowState state)
+internal sealed class SetMultipleVariablesExecutor(SetMultipleVariables model, WorkflowFormulaState state)
     : DeclarativeActionExecutor<SetMultipleVariables>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
@@ -28,7 +29,7 @@ internal sealed class SetMultipleVariablesExecutor(SetMultipleVariables model, D
             }
             else
             {
-                EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(assignment.Value);
+                EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(assignment.Value);
 
                 await this.AssignAsync(assignment.Variable, expressionResult.Value.ToFormula(), context).ConfigureAwait(false);
             }

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/SetTextVariableExecutor.cs

@@ -2,14 +2,16 @@
 
 using System.Threading;
 using System.Threading.Tasks;
+using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.PowerFx.Types;
 using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class SetTextVariableExecutor(SetTextVariable model, DeclarativeWorkflowState state)
+internal sealed class SetTextVariableExecutor(SetTextVariable model, WorkflowFormulaState state)
     : DeclarativeActionExecutor<SetTextVariable>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
@@ -22,7 +24,7 @@ internal sealed class SetTextVariableExecutor(SetTextVariable model, Declarative
         }
         else
         {
-            FormulaValue expressionResult = FormulaValue.New(this.State.Format(this.Model.Value));
+            FormulaValue expressionResult = FormulaValue.New(this.State.Engine.Format(this.Model.Value));
 
             await this.AssignAsync(variablePath, expressionResult, context).ConfigureAwait(false);
         }

dotnet/src/Microsoft.Agents.Workflows.Declarative/ObjectModel/SetVariableExecutor.cs

@@ -4,6 +4,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Agents.Workflows.Declarative.Interpreter;
+using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.PowerFx.Types;
@@ -11,7 +12,7 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.ObjectModel;
 
-internal sealed class SetVariableExecutor(SetVariable model, DeclarativeWorkflowState state)
+internal sealed class SetVariableExecutor(SetVariable model, WorkflowFormulaState state)
     : DeclarativeActionExecutor<SetVariable>(model, state)
 {
     protected override async ValueTask<object?> ExecuteAsync(IWorkflowContext context, CancellationToken cancellationToken)
@@ -24,7 +25,7 @@ internal sealed class SetVariableExecutor(SetVariable model, DeclarativeWorkflow
         }
         else
         {
-            EvaluationResult<DataValue> expressionResult = this.State.ExpressionEngine.GetValue(this.Model.Value);
+            EvaluationResult<DataValue> expressionResult = this.State.Evaluator.GetValue(this.Model.Value);
 
             await this.AssignAsync(variablePath, expressionResult.Value.ToFormula(), context).ConfigureAwait(false);
         }

dotnet/src/Microsoft.Agents.Workflows.Declarative/PowerFx/SystemScope.cs

@@ -1,12 +1,10 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using System.Collections.Frozen;
 using System.Collections.Generic;
-using System.Collections.Immutable;
 using System.Globalization;
-using System.Threading.Tasks;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
-using Microsoft.Agents.Workflows.Declarative.Interpreter;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.SystemVariables;
 using Microsoft.Extensions.AI;
@@ -16,6 +14,8 @@ namespace Microsoft.Agents.Workflows.Declarative.PowerFx;
 
 internal static class SystemScope
 {
+    private static readonly RecordValue s_emptyMessage = new ChatMessage(ChatRole.User, string.Empty).ToRecord();
+
     public static class Names
     {
         public const string Activity = nameof(Activity);
@@ -31,7 +31,7 @@ internal static class SystemScope
         public const string UserLanguage = nameof(UserLanguage);
     }
 
-    public static ImmutableHashSet<string> AllNames { get; } = GetNames().ToImmutableHashSet();
+    public static FrozenSet<string> AllNames { get; } = GetNames().ToFrozenSet();
 
     public static IEnumerable<string> GetNames()
     {
@@ -48,12 +48,12 @@ internal static class SystemScope
         yield return Names.UserLanguage;
     }
 
-    public static void InitializeSystem(this WorkflowScopes scopes)
+    public static void InitializeSystem(this WorkflowFormulaState scopes)
     {
         scopes.Set(Names.Activity, RecordValue.Empty(), VariableScopeNames.System);
         scopes.Set(Names.Bot, RecordValue.Empty(), VariableScopeNames.System);
 
-        scopes.Set(Names.LastMessage, FormulaType.String.NewBlank(), VariableScopeNames.System);
+        scopes.Set(Names.LastMessage, s_emptyMessage, VariableScopeNames.System);
         Set(Names.LastMessageId);
         Set(Names.LastMessageText);
 
@@ -95,21 +95,21 @@ internal static class SystemScope
         }
     }
 
-    public static FormulaValue GetConversationId(this DeclarativeWorkflowState state) =>
-        state.Get(VariableScopeNames.System, Names.ConversationId);
+    public static FormulaValue GetConversationId(this WorkflowFormulaState state) =>
+        state.Get(Names.ConversationId, VariableScopeNames.System);
 
-    public static async ValueTask SetConversationIdAsync(this DeclarativeWorkflowState state, IWorkflowContext context, string conversationId)
+    public static void SetConversationId(this WorkflowFormulaState state, string conversationId)
     {
-        RecordValue conversation = (RecordValue)state.Get(VariableScopeNames.System, Names.Conversation);
+        RecordValue conversation = (RecordValue)state.Get(Names.Conversation, VariableScopeNames.System);
         conversation.UpdateField("Id", FormulaValue.New(conversationId));
-        await state.SetAsync(VariableScopeNames.System, Names.Conversation, conversation, context).ConfigureAwait(false);
-        await state.SetAsync(VariableScopeNames.System, Names.ConversationId, FormulaValue.New(conversationId), context).ConfigureAwait(false);
+        state.Set(Names.Conversation, conversation, VariableScopeNames.System);
+        state.Set(Names.ConversationId, FormulaValue.New(conversationId), VariableScopeNames.System);
     }
 
-    public static async ValueTask SetLastMessageAsync(this DeclarativeWorkflowState state, IWorkflowContext context, ChatMessage message)
+    public static void SetLastMessage(this WorkflowFormulaState state, ChatMessage message)
     {
-        await state.SetAsync(VariableScopeNames.System, Names.LastMessage, message.ToRecord(), context).ConfigureAwait(false);
-        await state.SetAsync(VariableScopeNames.System, Names.LastMessageId, message.MessageId is null ? FormulaValue.NewBlank(FormulaType.String) : FormulaValue.New(message.MessageId), context).ConfigureAwait(false);
-        await state.SetAsync(VariableScopeNames.System, Names.LastMessageText, FormulaValue.New(message.Text), context).ConfigureAwait(false);
+        state.Set(Names.LastMessage, message.ToRecord(), VariableScopeNames.System);
+        state.Set(Names.LastMessageId, message.MessageId is null ? FormulaValue.NewBlank(FormulaType.String) : FormulaValue.New(message.MessageId), VariableScopeNames.System);
+        state.Set(Names.LastMessageText, FormulaValue.New(message.Text), VariableScopeNames.System);
     }
 }

dotnet/src/Microsoft.Agents.Workflows.Declarative/PowerFx/UnassignedValue.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+namespace Microsoft.Agents.Workflows.Declarative.PowerFx;
+
+/// <summary>
+/// Represents the absence of an assigned value for a variable used in an expression.
+/// </summary>
+public sealed record class UnassignedValue
+{
+    /// <summary>
+    /// A singleton instance of <see cref="UnassignedValue"/>.
+    /// </summary>
+    public static UnassignedValue Instance { get; } = new();
+}

dotnet/src/Microsoft.Agents.Workflows.Declarative/PowerFx/WorkflowDiagnostics.cs

@@ -1,6 +1,8 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using System.Collections.Frozen;
+using System.Collections.Generic;
 using System.Linq;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Bot.ObjectModel;
@@ -12,11 +14,23 @@ using Microsoft.PowerFx.Types;
 
 namespace Microsoft.Agents.Workflows.Declarative.PowerFx;
 
+internal sealed record class WorkflowTypeInfo(FrozenSet<string> EnvironmentVariables, IEnumerable<VariableInformationDiagnostic> UserVariables);
+
 internal static class WorkflowDiagnostics
 {
     private static readonly WorkflowFeatureConfiguration s_semanticFeatureConfig = new();
 
-    public static void Initialize<TElement>(this WorkflowScopes scopes, TElement workflowElement, IConfiguration? configuration) where TElement : BotElement, IDialogBase
+    public static WorkflowTypeInfo Describe<TElement>(this TElement workflowElement) where TElement : BotElement, IDialogBase
+    {
+        SemanticModel semanticModel = workflowElement.GetSemanticModel(new PowerFxExpressionChecker(s_semanticFeatureConfig), s_semanticFeatureConfig);
+
+        return
+            new WorkflowTypeInfo(
+                semanticModel.GetAllEnvironmentVariablesReferencedInTheBot().ToFrozenSet(),
+                semanticModel.GetVariables(workflowElement.SchemaName.Value).Where(x => !x.IsSystemVariable).Select(v => v.ToDiagnostic()));
+    }
+
+    public static void Initialize<TElement>(this WorkflowFormulaState scopes, TElement workflowElement, IConfiguration? configuration) where TElement : BotElement, IDialogBase
     {
         scopes.InitializeSystem();
 
@@ -25,7 +39,7 @@ internal static class WorkflowDiagnostics
         scopes.InitializeDefaults(semanticModel, workflowElement.SchemaName.Value);
     }
 
-    private static void InitializeEnvironment(this WorkflowScopes scopes, SemanticModel semanticModel, IConfiguration? configuration)
+    private static void InitializeEnvironment(this WorkflowFormulaState scopes, SemanticModel semanticModel, IConfiguration? configuration)
     {
         foreach (string variableName in semanticModel.GetAllEnvironmentVariablesReferencedInTheBot())
         {
@@ -35,7 +49,7 @@ internal static class WorkflowDiagnostics
         }
     }
 
-    private static void InitializeDefaults(this WorkflowScopes scopes, SemanticModel semanticModel, string schemaName)
+    private static void InitializeDefaults(this WorkflowFormulaState scopes, SemanticModel semanticModel, string schemaName)
     {
         foreach (VariableInformationDiagnostic variableDiagnostic in semanticModel.GetVariables(schemaName).Where(x => !x.IsSystemVariable).Select(v => v.ToDiagnostic()))
         {
@@ -54,7 +68,7 @@ internal static class WorkflowDiagnostics
                 }
             }
 
-            scopes.Set(variableDiagnostic.Path.VariableName, defaultValue, variableDiagnostic.Path.VariableScopeName ?? WorkflowScopes.DefaultScopeName);
+            scopes.Set(variableDiagnostic.Path.VariableName, defaultValue, variableDiagnostic.Path.VariableScopeName ?? WorkflowFormulaState.DefaultScopeName);
         }
     }
 

dotnet/src/Microsoft.Agents.Workflows.Declarative/PowerFx/WorkflowExpressionEngine.cs

@@ -13,7 +13,7 @@ using Microsoft.Shared.Diagnostics;
 
 namespace Microsoft.Agents.Workflows.Declarative.PowerFx;
 
-internal class WorkflowExpressionEngine : IExpressionEngine
+internal class WorkflowExpressionEngine
 {
     private readonly RecalcEngine _engine;
 
@@ -22,60 +22,26 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         this._engine = engine;
     }
 
-    public EvaluationResult<bool> GetValue(BoolExpression boolean, WorkflowScopes? state = null) => this.GetValue(boolean, state, this.EvaluateScope);
+    public EvaluationResult<bool> GetValue(BoolExpression boolean) => this.Evaluate(boolean);
 
-    public EvaluationResult<bool> GetValue(BoolExpression boolean, RecordDataValue state) => this.GetValue(boolean, state, this.EvaluateState);
+    public EvaluationResult<string> GetValue(StringExpression expression) => this.Evaluate(expression);
 
-    public EvaluationResult<string> GetValue(StringExpression expression, WorkflowScopes? state = null) => this.GetValue(expression, state, this.EvaluateScope);
+    public EvaluationResult<DataValue> GetValue(ValueExpression expression) => this.Evaluate(expression);
 
-    public EvaluationResult<string> GetValue(StringExpression expression, RecordDataValue state) => this.GetValue(expression, state, this.EvaluateState);
+    public EvaluationResult<long> GetValue(IntExpression expression) => this.Evaluate(expression);
 
-    public EvaluationResult<DataValue> GetValue(ValueExpression expression, WorkflowScopes? state = null) => this.GetValue(expression, state, this.EvaluateScope);
+    public EvaluationResult<double> GetValue(NumberExpression expression) => this.Evaluate(expression);
 
-    public EvaluationResult<DataValue> GetValue(ValueExpression expression, RecordDataValue state) => this.GetValue(expression, state, this.EvaluateState);
+    public EvaluationResult<TValue?> GetValue<TValue>(ObjectExpression<TValue> expression) where TValue : BotElement => this.Evaluate(expression);
 
-    public EvaluationResult<long> GetValue(IntExpression expression, WorkflowScopes? state = null) => this.GetValue(expression, state, this.EvaluateScope);
+    public ImmutableArray<T> GetValue<T>(ArrayExpression<T> expression) => this.Evaluate(expression).Value;
 
-    public EvaluationResult<long> GetValue(IntExpression expression, RecordDataValue state) => this.GetValue(expression, state, this.EvaluateState);
+    public ImmutableArray<T> GetValue<T>(ArrayExpressionOnly<T> expression) => this.Evaluate(expression).Value;
 
-    public EvaluationResult<double> GetValue(NumberExpression expression, WorkflowScopes? state = null) => this.GetValue(expression, state, this.EvaluateScope);
+    public EvaluationResult<TValue> GetValue<TValue>(EnumExpression<TValue> expression) where TValue : EnumWrapper =>
+        this.Evaluate<TValue>(expression);
 
-    public EvaluationResult<double> GetValue(NumberExpression expression, RecordDataValue state) => this.GetValue(expression, state, this.EvaluateState);
-
-    public EvaluationResult<TValue?> GetValue<TValue>(ObjectExpression<TValue> expression, WorkflowScopes? state = null) where TValue : BotElement => this.GetValue(expression, state, this.EvaluateScope);
-
-    public EvaluationResult<TValue?> GetValue<TValue>(ObjectExpression<TValue> expression, RecordDataValue state) where TValue : BotElement => this.GetValue(expression, state, this.EvaluateState);
-
-    public ImmutableArray<T> GetValue<T>(ArrayExpression<T> expression, WorkflowScopes? state = null) => this.GetValue(expression, state, this.EvaluateScope).Value;
-
-    public ImmutableArray<T> GetValue<T>(ArrayExpression<T> expression, RecordDataValue state) => this.GetValue(expression, state, this.EvaluateState).Value;
-
-    public ImmutableArray<T> GetValue<T>(ArrayExpressionOnly<T> expression, WorkflowScopes? state = null) => this.GetValue(expression, state, this.EvaluateScope).Value;
-
-    public ImmutableArray<T> GetValue<T>(ArrayExpressionOnly<T> expression, RecordDataValue state) => this.GetValue(expression, state, this.EvaluateState).Value;
-
-    public EvaluationResult<TValue> GetValue<TValue>(EnumExpression<TValue> expression, WorkflowScopes? state = null) where TValue : EnumWrapper =>
-        this.GetValue<TValue, WorkflowScopes>(expression, state, this.EvaluateScope);
-
-    public EvaluationResult<TValue> GetValue<TValue>(EnumExpression<TValue> expression, RecordDataValue state) where TValue : EnumWrapper =>
-        this.GetValue<TValue, RecordDataValue>(expression, state, this.EvaluateState);
-
-    public DialogSchemaName GetValue(DialogExpression expression, RecordDataValue state)
-    {
-        throw new NotSupportedException();
-    }
-
-    public EvaluationResult<string> GetValue(AdaptiveCardExpression expression, RecordDataValue state)
-    {
-        throw new NotSupportedException();
-    }
-
-    public EvaluationResult<FileDataValue?> GetValue(FileExpression expression, RecordDataValue state)
-    {
-        throw new NotSupportedException();
-    }
-
-    private EvaluationResult<bool> GetValue<TState>(BoolExpression expression, TState state, Func<ExpressionBase, TState, EvaluationResult<FormulaValue>> evaluator)
+    private EvaluationResult<bool> Evaluate(BoolExpression expression)
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -84,7 +50,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<bool>(expression.LiteralValue, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         if (expressionResult.Value is BlankValue)
         {
@@ -99,7 +65,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         return new EvaluationResult<bool>(formulaValue.Value, expressionResult.Sensitivity);
     }
 
-    private EvaluationResult<string> GetValue<TState>(StringExpression expression, TState state, Func<ExpressionBase, TState, EvaluationResult<FormulaValue>> evaluator)
+    private EvaluationResult<string> Evaluate(StringExpression expression)
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -108,7 +74,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<string>(expression.LiteralValue, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         if (expressionResult.Value is BlankValue)
         {
@@ -128,7 +94,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         return new EvaluationResult<string>(formulaValue.Value, expressionResult.Sensitivity);
     }
 
-    private EvaluationResult<long> GetValue<TState>(IntExpression expression, TState state, Func<ExpressionBase, TState, EvaluationResult<FormulaValue>> evaluator)
+    private EvaluationResult<long> Evaluate(IntExpression expression)
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -137,7 +103,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<long>(expression.LiteralValue, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         if (expressionResult.Value is BlankValue)
         {
@@ -152,7 +118,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         return new EvaluationResult<long>(Convert.ToInt64(formulaValue.Value), expressionResult.Sensitivity);
     }
 
-    private EvaluationResult<double> GetValue<TState>(NumberExpression expression, TState state, Func<ExpressionBase, TState, EvaluationResult<FormulaValue>> evaluator)
+    private EvaluationResult<double> Evaluate(NumberExpression expression)
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -161,7 +127,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<double>(expression.LiteralValue, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         if (expressionResult.Value is BlankValue)
         {
@@ -181,7 +147,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         return new EvaluationResult<double>(formulaValue.Value, expressionResult.Sensitivity);
     }
 
-    private EvaluationResult<DataValue> GetValue<TState>(ValueExpression expression, TState? state, Func<ExpressionBase, TState?, EvaluationResult<FormulaValue>> evaluator)
+    private EvaluationResult<DataValue> Evaluate(ValueExpression expression)
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -190,12 +156,12 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<DataValue>(expression.LiteralValue ?? BlankDataValue.Instance, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         return new EvaluationResult<DataValue>(expressionResult.Value.ToDataValue(), expressionResult.Sensitivity);
     }
 
-    private EvaluationResult<TValue> GetValue<TValue, TState>(EnumExpression<TValue> expression, TState? state, Func<ExpressionBase, TState?, EvaluationResult<FormulaValue>> evaluator) where TValue : EnumWrapper
+    private EvaluationResult<TValue> Evaluate<TValue>(EnumExpression<TValue> expression) where TValue : EnumWrapper
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -204,7 +170,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<TValue>(expression.LiteralValue, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         return expressionResult.Value switch
         {
@@ -216,7 +182,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         };
     }
 
-    private EvaluationResult<TValue?> GetValue<TValue, TState>(ObjectExpression<TValue> expression, TState state, Func<ExpressionBase, TState, EvaluationResult<FormulaValue>> evaluator) where TValue : BotElement
+    private EvaluationResult<TValue?> Evaluate<TValue>(ObjectExpression<TValue> expression) where TValue : BotElement
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -225,7 +191,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<TValue?>(expression.LiteralValue, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         if (expressionResult.Value is BlankValue)
         {
@@ -247,7 +213,7 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         }
     }
 
-    private EvaluationResult<ImmutableArray<TValue>> GetValue<TState, TValue>(ArrayExpression<TValue> expression, TState state, Func<ExpressionBase, TState, EvaluationResult<FormulaValue>> evaluator)
+    private EvaluationResult<ImmutableArray<TValue>> Evaluate<TValue>(ArrayExpression<TValue> expression)
     {
         Throw.IfNull(expression, nameof(expression));
 
@@ -256,16 +222,16 @@ internal class WorkflowExpressionEngine : IExpressionEngine
             return new EvaluationResult<ImmutableArray<TValue>>(expression.LiteralValue, SensitivityLevel.None);
         }
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         return new EvaluationResult<ImmutableArray<TValue>>(ParseArrayResults<TValue>(expressionResult.Value), expressionResult.Sensitivity);
     }
 
-    private EvaluationResult<ImmutableArray<TValue>> GetValue<TState, TValue>(ArrayExpressionOnly<TValue> expression, TState state, Func<ExpressionBase, TState, EvaluationResult<FormulaValue>> evaluator)
+    private EvaluationResult<ImmutableArray<TValue>> Evaluate<TValue>(ArrayExpressionOnly<TValue> expression)
     {
         Throw.IfNull(expression, nameof(expression));
 
-        EvaluationResult<FormulaValue> expressionResult = evaluator.Invoke(expression, state);
+        EvaluationResult<FormulaValue> expressionResult = this.EvaluateScope(expression);
 
         return new EvaluationResult<ImmutableArray<TValue>>(ParseArrayResults<TValue>(expressionResult.Value), expressionResult.Sensitivity);
     }
@@ -302,40 +268,11 @@ internal class WorkflowExpressionEngine : IExpressionEngine
         }
     }
 
-    private EvaluationResult<FormulaValue> EvaluateState(ExpressionBase expression, RecordDataValue? state)
-    {
-        if (state is not null)
-        {
-            foreach (KeyValuePair<string, DataValue> kvp in state.Properties)
-            {
-                if (kvp.Value is RecordDataValue scopeRecord)
-                {
-                    Bind(kvp.Key, scopeRecord.ToRecordValue());
-                }
-            }
-        }
-
-        return this.Evaluate(expression);
-
-        void Bind(string scopeName, RecordValue stateRecord)
-        {
-            this._engine.DeleteFormula(scopeName);
-            this._engine.UpdateVariable(scopeName, stateRecord);
-        }
-    }
-
-    private EvaluationResult<FormulaValue> EvaluateScope(ExpressionBase expression, WorkflowScopes? state = null)
-    {
-        state?.Bind(this._engine);
-
-        return this.Evaluate(expression);
-    }
-
-    private EvaluationResult<FormulaValue> Evaluate(ExpressionBase expression)
+    private EvaluationResult<FormulaValue> EvaluateScope(ExpressionBase expression)
     {
         string? expressionText =
             expression.IsVariableReference ?
-            expression.VariableReference?.Format() :
+            expression.VariableReference?.ToString() :
             expression.ExpressionText;
 
         return new(this._engine.Eval(expressionText), SensitivityLevel.None);

dotnet/src/Microsoft.Agents.Workflows.Declarative/PowerFx/WorkflowFormulaState.cs

@@ -0,0 +1,191 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.Collections.Frozen;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading;
+using System.Threading.Tasks;
+using Microsoft.Agents.Workflows.Declarative.Extensions;
+using Microsoft.Bot.ObjectModel;
+using Microsoft.PowerFx;
+using Microsoft.PowerFx.Types;
+using Microsoft.Shared.Diagnostics;
+
+namespace Microsoft.Agents.Workflows.Declarative.PowerFx;
+
+/// <summary>
+/// Contains all variables scopes for a workflow.
+/// </summary>
+internal sealed class WorkflowFormulaState
+{
+    // ISSUE #488 - Update default scope for workflows to `Workflow` (instead of `Topic`)
+    public const string DefaultScopeName = VariableScopeNames.Topic;
+
+    private static readonly FrozenSet<string> s_mutableScopes =
+        [
+            VariableScopeNames.Topic,
+            VariableScopeNames.Global,
+            VariableScopeNames.System,
+        ];
+
+    private readonly Dictionary<string, WorkflowScope> _scopes;
+    private int _isInitialized;
+
+    public RecalcEngine Engine { get; }
+
+    public WorkflowExpressionEngine Evaluator { get; }
+
+    public WorkflowFormulaState(RecalcEngine engine)
+    {
+        this.Engine = engine;
+        this.Evaluator = new WorkflowExpressionEngine(engine);
+        this._scopes = VariableScopeNames.AllScopes.ToDictionary(scopeName => scopeName, scopeName => new WorkflowScope(scopeName));
+        this.Bind();
+    }
+
+    public FormulaValue Get(PropertyPath variablePath) => this.Get(Throw.IfNull(variablePath.VariableName), variablePath.VariableScopeName);
+
+    public FormulaValue Get(string variableName, string? scopeName = null)
+    {
+        if (this.GetScope(scopeName).TryGetValue(variableName, out FormulaValue? value))
+        {
+            return value;
+        }
+
+        return FormulaValue.NewBlank();
+    }
+
+    public void ResetAll(string? scopeName = null)
+    {
+        if (scopeName is not null)
+        {
+            this.GetScope(scopeName).ResetAll();
+        }
+        else
+        {
+            foreach (string targetScope in VariableScopeNames.AllScopes)
+            {
+                this.GetScope(targetScope).ResetAll();
+            }
+        }
+
+        this.Bind();
+    }
+
+    public void Reset(PropertyPath variablePath) => this.Reset(Throw.IfNull(variablePath.VariableName), variablePath.VariableScopeName);
+
+    public void Reset(string variableName, string? scopeName = null)
+    {
+        this.GetScope(scopeName).Reset(variableName);
+        this.Bind();
+    }
+
+    public void Set(PropertyPath variablePath, FormulaValue value) => this.Set(Throw.IfNull(variablePath.VariableName), value, variablePath.VariableScopeName);
+
+    public void Set(string variableName, FormulaValue value, string? scopeName = null)
+    {
+        this.GetScope(scopeName)[variableName] = value;
+        this.Bind();
+    }
+
+    public bool SetInitialized() => Interlocked.CompareExchange(ref this._isInitialized, 1, 0) == 0;
+
+    public async ValueTask RestoreAsync(IWorkflowContext context, CancellationToken cancellationToken)
+    {
+        if (!this.SetInitialized())
+        {
+            return;
+        }
+
+        await Task.WhenAll(s_mutableScopes.Select(scopeName => ReadScopeAsync(scopeName))).ConfigureAwait(false);
+
+        async Task ReadScopeAsync(string scopeName)
+        {
+            HashSet<string> keys = await context.ReadStateKeysAsync(scopeName).ConfigureAwait(false);
+            foreach (string key in keys)
+            {
+                object? value = await context.ReadStateAsync<object>(key, scopeName).ConfigureAwait(false);
+                if (value is null || value is UnassignedValue)
+                {
+                    value = FormulaValue.NewBlank();
+                }
+                this.Set(key, value.ToFormula(), scopeName);
+            }
+
+            this.Bind(scopeName);
+        }
+    }
+
+    public RecordValue BuildRecord(string scopeName) => this.GetScope(scopeName).BuildRecord();
+
+    public void Bind(string? targetScope = null)
+    {
+        if (targetScope is not null)
+        {
+            Bind(targetScope);
+        }
+        else
+        {
+            foreach (string scopeName in VariableScopeNames.AllScopes)
+            {
+                Bind(scopeName);
+            }
+        }
+
+        void Bind(string scopeName)
+        {
+            RecordValue scopeRecord = this.BuildRecord(scopeName);
+            this.Engine.DeleteFormula(scopeName);
+            this.Engine.UpdateVariable(scopeName, scopeRecord);
+        }
+    }
+
+    private WorkflowScope GetScope(string? scopeName)
+    {
+        scopeName ??= WorkflowFormulaState.DefaultScopeName;
+
+        if (!VariableScopeNames.IsValidName(scopeName))
+        {
+            throw new DeclarativeActionException($"Invalid variable scope name: '{scopeName}'.");
+        }
+
+        return this._scopes[scopeName];
+    }
+
+    /// <summary>
+    /// The set of variables for a specific action scope.
+    /// </summary>
+    private sealed class WorkflowScope(string scopeName) : Dictionary<string, FormulaValue>
+    {
+        public string Name => scopeName;
+
+        public void ResetAll()
+        {
+            foreach (string variableName in this.Keys.ToArray())
+            {
+                this.Reset(variableName);
+            }
+        }
+
+        public void Reset(string variableName)
+        {
+            if (this.TryGetValue(variableName, out FormulaValue? value))
+            {
+                this[variableName] = value.Type.NewBlank();
+            }
+        }
+
+        public RecordValue BuildRecord()
+        {
+            return FormulaValue.NewRecordFromFields(GetFields());
+
+            IEnumerable<NamedValue> GetFields()
+            {
+                foreach (KeyValuePair<string, FormulaValue> kvp in this)
+                {
+                    yield return new NamedValue(kvp.Key, kvp.Value);
+                }
+            }
+        }
+    }
+}

dotnet/src/Microsoft.Agents.Workflows.Declarative/PowerFx/WorkflowScopes.cs

@@ -1,129 +0,0 @@
-// Copyright (c) Microsoft. All rights reserved.
-
-using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.Linq;
-using Microsoft.Agents.Workflows.Declarative.Extensions;
-using Microsoft.Bot.ObjectModel;
-using Microsoft.PowerFx;
-using Microsoft.PowerFx.Types;
-
-namespace Microsoft.Agents.Workflows.Declarative.PowerFx;
-
-/// <summary>
-/// Contains all action scopes for a process.
-/// </summary>
-internal sealed class WorkflowScopes
-{
-    // ISSUE #488 - Update default scope for workflows to `Workflow` (instead of `Topic`)
-    public const string DefaultScopeName = VariableScopeNames.Topic;
-
-    private readonly ImmutableDictionary<string, WorkflowScope> _scopes;
-
-    public WorkflowScopes()
-    {
-        this._scopes = VariableScopeNames.AllScopes.ToDictionary(scopeName => scopeName, scopeName => new WorkflowScope(scopeName)).ToImmutableDictionary();
-    }
-
-    public FormulaValue Get(string variableName, string? scopeName = null)
-    {
-        if (this._scopes[scopeName ?? WorkflowScopes.DefaultScopeName].TryGetValue(variableName, out FormulaValue? value))
-        {
-            return value;
-        }
-
-        return FormulaValue.NewBlank();
-    }
-
-    public void Clear(string scopeName) => this._scopes[scopeName].Reset();
-
-    public void Reset(string variableName, string? scopeName = null) => this._scopes[scopeName ?? WorkflowScopes.DefaultScopeName].Reset(variableName);
-
-    public void Set(string variableName, FormulaValue value, string? scopeName = null) => this._scopes[scopeName ?? WorkflowScopes.DefaultScopeName][variableName] = value;
-
-    public RecordValue BuildRecord(string scopeName) => this._scopes[scopeName].BuildRecord();
-
-    public RecordDataValue BuildState()
-    {
-        return DataValue.RecordFromFields(BuildStateFields());
-
-        IEnumerable<KeyValuePair<string, DataValue>> BuildStateFields()
-        {
-            foreach (KeyValuePair<string, WorkflowScope> kvp in this._scopes)
-            {
-                yield return new(kvp.Key, kvp.Value.BuildState());
-            }
-        }
-    }
-
-    public void Bind(RecalcEngine engine, string? type = null)
-    {
-        if (type is not null)
-        {
-            Bind(type);
-        }
-        else
-        {
-            foreach (string scopeName in VariableScopeNames.AllScopes)
-            {
-                Bind(scopeName);
-            }
-        }
-
-        void Bind(string scopeName)
-        {
-            RecordValue scopeRecord = this.BuildRecord(scopeName);
-            engine.DeleteFormula(scopeName);
-            engine.UpdateVariable(scopeName, scopeRecord);
-        }
-    }
-
-    /// <summary>
-    /// The set of variables for a specific action scope.
-    /// </summary>
-    private sealed class WorkflowScope(string scopeName) : Dictionary<string, FormulaValue>
-    {
-        public string Name => scopeName;
-
-        public void Reset()
-        {
-            foreach (string variableName in this.Keys.ToArray())
-            {
-                this.Reset(variableName);
-            }
-        }
-
-        public void Reset(string variableName)
-        {
-            if (this.TryGetValue(variableName, out FormulaValue? value))
-            {
-                this[variableName] = value.Type.NewBlank();
-            }
-        }
-
-        public RecordValue BuildRecord()
-        {
-            return FormulaValue.NewRecordFromFields(GetFields());
-
-            IEnumerable<NamedValue> GetFields()
-            {
-                foreach (KeyValuePair<string, FormulaValue> kvp in this)
-                {
-                    yield return new NamedValue(kvp.Key, kvp.Value);
-                }
-            }
-        }
-
-        public RecordDataValue BuildState()
-        {
-            RecordDataValue.Builder recordBuilder = new();
-
-            foreach (KeyValuePair<string, FormulaValue> kvp in this)
-            {
-                recordBuilder.Properties.Add(kvp.Key, kvp.Value.ToDataValue());
-            }
-
-            return recordBuilder.Build();
-        }
-    }
-}

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/DeclarativeWorkflowTest.cs

@@ -135,6 +135,8 @@ public sealed class DeclarativeWorkflowTest(ITestOutputHelper output) : Workflow
     [InlineData("EditTable.yaml", 2, "edit_var")]
     [InlineData("EditTableV2.yaml", 2, "edit_var")]
     [InlineData("ParseValue.yaml", 1, "parse_var")]
+    [InlineData("SendActivity.yaml", 2, "activity_input")]
+    [InlineData("SetVariable.yaml", 1, "set_var")]
     [InlineData("SetTextVariable.yaml", 1, "set_text")]
     [InlineData("ClearAllVariables.yaml", 1, "clear_all")]
     [InlineData("ResetVariable.yaml", 2, "clear_var")]
@@ -197,11 +199,12 @@ public sealed class DeclarativeWorkflowTest(ITestOutputHelper output) : Workflow
             };
         AdaptiveDialog dialog = dialogBuilder.Build();
 
-        WorkflowScopes scopes = new();
+        WorkflowFormulaState state = new(RecalcEngineFactory.Create());
         Mock<WorkflowAgentProvider> mockAgentProvider = new(MockBehavior.Strict);
         DeclarativeWorkflowOptions options = new(mockAgentProvider.Object);
-        WorkflowActionVisitor visitor = new(new RootExecutor(), new DeclarativeWorkflowState(RecalcEngineFactory.Create()), options);
-        WorkflowElementWalker walker = new(dialog, visitor);
+        WorkflowActionVisitor visitor = new(new RootExecutor(), state, options);
+        WorkflowElementWalker walker = new(visitor);
+        walker.Visit(dialog);
         Assert.True(visitor.HasUnsupportedActions);
     }
 

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/ObjectModel/ClearAllVariablesExecutorTest.cs

@@ -17,7 +17,7 @@ public sealed class ClearAllVariablesExecutorTest(ITestOutputHelper output) : Wo
     public async Task ClearWorkflowScope()
     {
         // Arrange
-        this.Scopes.Set("NoVar", FormulaValue.New("Old value"));
+        this.State.Set("NoVar", FormulaValue.New("Old value"));
 
         ClearAllVariables model =
             this.CreateModel(
@@ -25,7 +25,7 @@ public sealed class ClearAllVariablesExecutorTest(ITestOutputHelper output) : Wo
                 VariablesToClear.ConversationScopedVariables);
 
         // Act
-        ClearAllVariablesExecutor action = new(model, this.GetState());
+        ClearAllVariablesExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert
@@ -43,7 +43,7 @@ public sealed class ClearAllVariablesExecutorTest(ITestOutputHelper output) : Wo
                 VariablesToClear.UserScopedVariables);
 
         // Act
-        ClearAllVariablesExecutor action = new(model, this.GetState());
+        ClearAllVariablesExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/ObjectModel/ParseValueExecutorTest.cs

@@ -32,7 +32,7 @@ public sealed class ParseValueExecutorTest(ITestOutputHelper output) : WorkflowA
                 @"{ ""key1"": ""val1"" }");
 
         // Act
-        ParseValueExecutor action = new(model, this.GetState());
+        ParseValueExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert
@@ -51,7 +51,7 @@ public sealed class ParseValueExecutorTest(ITestOutputHelper output) : WorkflowA
                 "True");
 
         // Act
-        ParseValueExecutor action = new(model, this.GetState());
+        ParseValueExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert
@@ -70,7 +70,7 @@ public sealed class ParseValueExecutorTest(ITestOutputHelper output) : WorkflowA
                 "42");
 
         // Act
-        ParseValueExecutor action = new(model, this.GetState());
+        ParseValueExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert
@@ -89,7 +89,7 @@ public sealed class ParseValueExecutorTest(ITestOutputHelper output) : WorkflowA
                 "Hello, World!");
 
         // Act
-        ParseValueExecutor action = new(model, this.GetState());
+        ParseValueExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/ObjectModel/ResetVariableExecutorTest.cs

@@ -17,8 +17,8 @@ public sealed class ResetVariableExecutorTest(ITestOutputHelper output) : Workfl
     public async Task ResetDefinedValue()
     {
         // Arrange
-        this.Scopes.Set("MyVar1", FormulaValue.New("Value #1"));
-        this.Scopes.Set("MyVar2", FormulaValue.New("Value #2"));
+        this.State.Set("MyVar1", FormulaValue.New("Value #1"));
+        this.State.Set("MyVar2", FormulaValue.New("Value #2"));
 
         ResetVariable model =
             this.CreateModel(
@@ -26,7 +26,7 @@ public sealed class ResetVariableExecutorTest(ITestOutputHelper output) : Workfl
                 FormatVariablePath("MyVar1"));
 
         // Act
-        ResetVariableExecutor action = new(model, this.GetState());
+        ResetVariableExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert
@@ -39,7 +39,7 @@ public sealed class ResetVariableExecutorTest(ITestOutputHelper output) : Workfl
     public async Task ResetUndefinedValue()
     {
         // Arrange
-        this.Scopes.Set("MyVar1", FormulaValue.New("Value #1"));
+        this.State.Set("MyVar1", FormulaValue.New("Value #1"));
 
         ResetVariable model =
             this.CreateModel(
@@ -47,7 +47,7 @@ public sealed class ResetVariableExecutorTest(ITestOutputHelper output) : Workfl
                 FormatVariablePath("NoVar"));
 
         // Act
-        ResetVariableExecutor action = new(model, this.GetState());
+        ResetVariableExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/ObjectModel/SendActivityExecutorTest.cs

@@ -22,7 +22,7 @@ public sealed class SendActivityExecutorTest(ITestOutputHelper output) : Workflo
                 "Test activity message");
 
         // Act
-        SendActivityExecutor action = new(model, this.GetState());
+        SendActivityExecutor action = new(model, this.State);
         WorkflowEvent[] events = await this.Execute(action);
 
         // Assert

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/ObjectModel/SetTextVariableExecutorTest.cs

@@ -24,7 +24,7 @@ public sealed class SetTextVariableExecutorTest(ITestOutputHelper output) : Work
                 "Text variable value");
 
         // Act
-        SetTextVariableExecutor action = new(model, this.GetState());
+        SetTextVariableExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert
@@ -36,7 +36,7 @@ public sealed class SetTextVariableExecutorTest(ITestOutputHelper output) : Work
     public async Task UpdateExistingValue()
     {
         // Arrange
-        this.Scopes.Set("TextVar", FormulaValue.New("Old value"));
+        this.State.Set("TextVar", FormulaValue.New("Old value"));
 
         SetTextVariable model =
             this.CreateModel(
@@ -45,7 +45,7 @@ public sealed class SetTextVariableExecutorTest(ITestOutputHelper output) : Work
                 "New value");
 
         // Act
-        SetTextVariableExecutor action = new(model, this.GetState());
+        SetTextVariableExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/ObjectModel/SetVariableExecutorTest.cs

@@ -17,7 +17,7 @@ public sealed class SetVariableExecutorTest(ITestOutputHelper output) : Workflow
     public void InvalidModel()
     {
         // Arrange, Act, Assert
-        Assert.Throws<DeclarativeModelException>(() => new SetVariableExecutor(new SetVariable(), this.GetState()));
+        Assert.Throws<DeclarativeModelException>(() => new SetVariableExecutor(new SetVariable(), this.State));
     }
 
     [Fact]
@@ -99,7 +99,7 @@ public sealed class SetVariableExecutorTest(ITestOutputHelper output) : Workflow
     public async Task SetBooleanVariable()
     {
         // Arrange
-        this.Scopes.Set("Source", FormulaValue.New(true));
+        this.State.Set("Source", FormulaValue.New(true));
         ValueExpression.Builder expressionBuilder = new(ValueExpression.Variable(PropertyPath.TopicVariable("Source")));
 
         // Act, Assert
@@ -114,7 +114,7 @@ public sealed class SetVariableExecutorTest(ITestOutputHelper output) : Workflow
     public async Task SetNumberVariable()
     {
         // Arrange
-        this.Scopes.Set("Source", FormulaValue.New(321));
+        this.State.Set("Source", FormulaValue.New(321));
         ValueExpression.Builder expressionBuilder = new(ValueExpression.Variable(PropertyPath.TopicVariable("Source")));
 
         // Act, Assert
@@ -129,7 +129,7 @@ public sealed class SetVariableExecutorTest(ITestOutputHelper output) : Workflow
     public async Task SetStringVariable()
     {
         // Arrange
-        this.Scopes.Set("Source", FormulaValue.New("Test"));
+        this.State.Set("Source", FormulaValue.New("Test"));
         ValueExpression.Builder expressionBuilder = new(ValueExpression.Variable(PropertyPath.TopicVariable("Source")));
 
         // Act, Assert
@@ -144,7 +144,7 @@ public sealed class SetVariableExecutorTest(ITestOutputHelper output) : Workflow
     public async Task UpdateExistingValue()
     {
         // Arrange
-        this.Scopes.Set("VarA", FormulaValue.New(33));
+        this.State.Set("VarA", FormulaValue.New(33));
 
         // Act, Assert
         await this.ExecuteTest(
@@ -180,10 +180,10 @@ public sealed class SetVariableExecutorTest(ITestOutputHelper output) : Workflow
                 FormatVariablePath(variableName),
                 valueExpression);
 
-        this.Scopes.Set(variableName, FormulaValue.New(33));
+        this.State.Set(variableName, FormulaValue.New(33));
 
         // Act
-        SetVariableExecutor action = new(model, this.GetState());
+        SetVariableExecutor action = new(model, this.State);
         await this.Execute(action);
 
         // Assert

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/ObjectModel/WorkflowActionExecutorTest.cs

@@ -18,9 +18,7 @@ namespace Microsoft.Agents.Workflows.Declarative.UnitTests.ObjectModel;
 /// </summary>
 public abstract class WorkflowActionExecutorTest(ITestOutputHelper output) : WorkflowTest(output)
 {
-    internal WorkflowScopes Scopes { get; } = new();
-
-    internal DeclarativeWorkflowState GetState() => new(RecalcEngineFactory.Create(), this.Scopes);
+    internal WorkflowFormulaState State { get; } = new(RecalcEngineFactory.Create());
 
     protected ActionId CreateActionId() => new($"{this.GetType().Name}_{Guid.NewGuid():N}");
 
@@ -31,7 +29,7 @@ public abstract class WorkflowActionExecutorTest(ITestOutputHelper output) : Wor
         TestWorkflowExecutor workflowExecutor = new();
         WorkflowBuilder workflowBuilder = new(workflowExecutor);
         workflowBuilder.AddEdge(workflowExecutor, executor);
-        StreamingRun run = await InProcessExecution.StreamAsync(workflowBuilder.Build<WorkflowScopes>(), this.Scopes);
+        StreamingRun run = await InProcessExecution.StreamAsync(workflowBuilder.Build<WorkflowFormulaState>(), this.State);
         WorkflowEvent[] events = await run.WatchStreamAsync().ToArrayAsync();
         Assert.Contains(events, e => e is DeclarativeActionInvokeEvent);
         Assert.Contains(events, e => e is DeclarativeActionCompleteEvent);
@@ -48,7 +46,7 @@ public abstract class WorkflowActionExecutorTest(ITestOutputHelper output) : Wor
 
     internal void VerifyState(string variableName, string scopeName, FormulaValue expectedValue)
     {
-        FormulaValue actualValue = this.Scopes.Get(variableName, scopeName);
+        FormulaValue actualValue = this.State.Get(variableName, scopeName);
         Assert.Equal(expectedValue.Format(), actualValue.Format());
     }
 
@@ -56,7 +54,7 @@ public abstract class WorkflowActionExecutorTest(ITestOutputHelper output) : Wor
 
     internal void VerifyUndefined(string variableName, string scopeName)
     {
-        Assert.IsType<BlankValue>(this.Scopes.Get(variableName, scopeName));
+        Assert.IsType<BlankValue>(this.State.Get(variableName, scopeName));
     }
 
     protected TAction AssignParent<TAction>(DialogAction.Builder actionBuilder) where TAction : DialogAction
@@ -76,9 +74,9 @@ public abstract class WorkflowActionExecutorTest(ITestOutputHelper output) : Wor
 
     internal sealed class TestWorkflowExecutor() :
         ReflectingExecutor<TestWorkflowExecutor>(nameof(TestWorkflowExecutor)),
-        IMessageHandler<WorkflowScopes>
+        IMessageHandler<WorkflowFormulaState>
     {
-        public async ValueTask HandleAsync(WorkflowScopes message, IWorkflowContext context)
+        public async ValueTask HandleAsync(WorkflowFormulaState message, IWorkflowContext context)
         {
             await context.SendMessageAsync(new ExecutorResultMessage(this.Id)).ConfigureAwait(false);
         }

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/PowerFx/RecalcEngineFactoryTests.cs

@@ -10,12 +10,12 @@ using Xunit.Abstractions;
 
 namespace Microsoft.Agents.Workflows.Declarative.UnitTests.PowerFx;
 
-public class RecalcEngineFactoryTests(ITestOutputHelper output) : RecalcEngineTest(output)
+public class RecalcEngineFactoryTests(ITestOutputHelper output) : WorkflowTest(output)
 {
     [Fact]
     public void VariableUpdateTest()
     {
-        RecalcEngine engine = this.CreateEngine();
+        RecalcEngine engine = RecalcEngineFactory.Create();
 
         FormulaValue evalResult;
 
@@ -60,7 +60,7 @@ public class RecalcEngineFactoryTests(ITestOutputHelper output) : RecalcEngineTe
     public void DefaultNotNull()
     {
         // Act
-        RecalcEngine engine = this.CreateEngine();
+        RecalcEngine engine = RecalcEngineFactory.Create();
 
         // Assert
         Assert.NotNull(engine);
@@ -70,8 +70,8 @@ public class RecalcEngineFactoryTests(ITestOutputHelper output) : RecalcEngineTe
     public void NewInstanceEachTime()
     {
         // Act
-        RecalcEngine engine1 = this.CreateEngine();
-        RecalcEngine engine2 = this.CreateEngine();
+        RecalcEngine engine1 = RecalcEngineFactory.Create();
+        RecalcEngine engine2 = RecalcEngineFactory.Create();
 
         // Assert
         Assert.NotNull(engine1);
@@ -83,7 +83,7 @@ public class RecalcEngineFactoryTests(ITestOutputHelper output) : RecalcEngineTe
     public void HasSetFunctionEnabled()
     {
         // Arrange
-        RecalcEngine engine = this.CreateEngine();
+        RecalcEngine engine = RecalcEngineFactory.Create();
 
         // Act
         CheckResult result = engine.Check("1+1");

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/PowerFx/RecalcEngineTest.cs

@@ -11,7 +11,7 @@ namespace Microsoft.Agents.Workflows.Declarative.UnitTests.PowerFx;
 /// </summary>
 public abstract class RecalcEngineTest(ITestOutputHelper output) : WorkflowTest(output)
 {
-    internal WorkflowScopes Scopes { get; } = new();
+    internal WorkflowFormulaState State { get; } = new(RecalcEngineFactory.Create());
 
-    protected RecalcEngine CreateEngine(int maximumExpressionLength = 500) => RecalcEngineFactory.Create(maximumExpressionLength);
+    protected RecalcEngine Engine => this.State.Engine;
 }

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/PowerFx/TemplateExtensionsTests.cs

@@ -3,7 +3,6 @@
 using System.Collections.Generic;
 using Microsoft.Agents.Workflows.Declarative.Extensions;
 using Microsoft.Bot.ObjectModel;
-using Microsoft.PowerFx;
 using Microsoft.PowerFx.Types;
 using Xunit.Abstractions;
 
@@ -21,10 +20,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
             TemplateLine.Parse(" "),
             TemplateLine.Parse("World"),
         ];
-        RecalcEngine engine = this.CreateEngine();
 
         // Act
-        string? result = engine.Format(template);
+        string? result = this.Engine.Format(template);
 
         // Assert
         Assert.Equal("Hello World", result);
@@ -35,10 +33,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
     {
         // Arrange
         List<TemplateLine> template = [];
-        RecalcEngine engine = this.CreateEngine();
 
         // Act
-        string? result = engine.Format(template);
+        string? result = this.Engine.Format(template);
 
         // Assert
         Assert.Equal(string.Empty, result);
@@ -49,10 +46,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
     {
         // Arrange
         TemplateLine line = TemplateLine.Parse("Test");
-        RecalcEngine engine = this.CreateEngine();
 
         // Act
-        string? result = engine.Format(line);
+        string? result = this.Engine.Format(line);
 
         // Assert
         Assert.Equal("Test", result);
@@ -63,10 +59,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
     {
         // Arrange
         TemplateLine? line = null;
-        RecalcEngine engine = this.CreateEngine();
 
         // Act
-        string? result = engine.Format(line);
+        string? result = this.Engine.Format(line);
 
         // Assert
         Assert.Equal(string.Empty, result);
@@ -78,10 +73,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
         // Arrange
         TemplateSegment textSegment = TextSegment.FromText("Hello World");
         TemplateLine line = new([textSegment]);
-        RecalcEngine engine = this.CreateEngine();
 
         // Act
-        string? result = engine.Format(line);
+        string? result = this.Engine.Format(line);
 
         // Assert
         Assert.Equal("Hello World", result);
@@ -93,10 +87,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
         // Arrange
         ExpressionSegment expressionSegment = new(ValueExpression.Expression("1 + 1"));
         TemplateLine line = new([expressionSegment]);
-        RecalcEngine engine = this.CreateEngine();
 
         // Act
-        string? result = engine.Format(line);
+        string? result = this.Engine.Format(line);
 
         // Assert
         Assert.Equal("2", result);
@@ -106,14 +99,12 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
     public void FormatVariableSegment()
     {
         // Arrange
-        this.Scopes.Set("Source", FormulaValue.New("Hello World"));
+        this.State.Set("Source", FormulaValue.New("Hello World"));
         ExpressionSegment expressionSegment = new(ValueExpression.Variable(PropertyPath.TopicVariable("Source")));
         TemplateLine line = new([expressionSegment]);
-        RecalcEngine engine = this.CreateEngine();
-        this.Scopes.Bind(engine);
 
         // Act
-        string? result = engine.Format(line);
+        string? result = this.Engine.Format(line);
 
         // Assert
         Assert.Equal("Hello World", result);
@@ -125,10 +116,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
         // Arrange
         ExpressionSegment expressionSegment = new();
         TemplateLine line = new([expressionSegment]);
-        RecalcEngine engine = this.CreateEngine();
 
         // Act & Assert
-        Assert.Throws<DeclarativeModelException>(() => engine.Format(line));
+        Assert.Throws<DeclarativeModelException>(() => this.Engine.Format(line));
     }
 
     [Fact]
@@ -138,10 +128,9 @@ public class TemplateExtensionsTests(ITestOutputHelper output) : RecalcEngineTes
         TemplateSegment textSegment = TextSegment.FromText("Hello ");
         ExpressionSegment expressionSegment = new(ValueExpression.Expression(@"""World"""));
         TemplateLine line = new([textSegment, expressionSegment]);
-        RecalcEngine engine = this.CreateEngine();
 
         // Act
-        string? result = engine.Format(line);
+        string? result = this.Engine.Format(line);
 
         // Assert
         Assert.Equal("Hello World", result);

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/PowerFx/WorkflowExpressionEngineTests.cs

@@ -7,7 +7,6 @@ using Microsoft.Agents.Workflows.Declarative.PowerFx;
 using Microsoft.Bot.ObjectModel;
 using Microsoft.Bot.ObjectModel.Abstractions;
 using Microsoft.Bot.ObjectModel.Exceptions;
-using Microsoft.PowerFx;
 using Microsoft.PowerFx.Types;
 using Xunit.Abstractions;
 
@@ -34,39 +33,17 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
     public WorkflowExpressionEngineTests(ITestOutputHelper output)
         : base(output)
     {
-        this.Scopes.Set(Variables.GlobalValue, FormulaValue.New(255), VariableScopeNames.Global);
-        this.Scopes.Set(Variables.BoolValue, FormulaValue.New(true), VariableScopeNames.Topic);
-        this.Scopes.Set(Variables.StringValue, FormulaValue.New("Hello World"), VariableScopeNames.Topic);
-        this.Scopes.Set(Variables.IntValue, FormulaValue.New(long.MaxValue), VariableScopeNames.Topic);
-        this.Scopes.Set(Variables.NumberValue, FormulaValue.New(33.3), VariableScopeNames.Topic);
-        this.Scopes.Set(Variables.EnumValue, FormulaValue.New(nameof(VariablesToClear.ConversationScopedVariables)), VariableScopeNames.Topic);
-        this.Scopes.Set(Variables.ObjectValue, ObjectData, VariableScopeNames.Topic);
-        this.Scopes.Set(Variables.ArrayValue, TableData, VariableScopeNames.Topic);
-        this.Scopes.Set(Variables.BlankValue, FormulaValue.NewBlank(), VariableScopeNames.Topic);
+        this.State.Set(Variables.GlobalValue, FormulaValue.New(255), VariableScopeNames.Global);
+        this.State.Set(Variables.BoolValue, FormulaValue.New(true), VariableScopeNames.Topic);
+        this.State.Set(Variables.StringValue, FormulaValue.New("Hello World"), VariableScopeNames.Topic);
+        this.State.Set(Variables.IntValue, FormulaValue.New(long.MaxValue), VariableScopeNames.Topic);
+        this.State.Set(Variables.NumberValue, FormulaValue.New(33.3), VariableScopeNames.Topic);
+        this.State.Set(Variables.EnumValue, FormulaValue.New(nameof(VariablesToClear.ConversationScopedVariables)), VariableScopeNames.Topic);
+        this.State.Set(Variables.ObjectValue, ObjectData, VariableScopeNames.Topic);
+        this.State.Set(Variables.ArrayValue, TableData, VariableScopeNames.Topic);
+        this.State.Set(Variables.BlankValue, FormulaValue.NewBlank(), VariableScopeNames.Topic);
     }
 
-    #region Unsupported Expression Tests
-
-    [Fact]
-    public void AdaptiveCardExpressionGetValueUnsupported()
-    {
-        this.EvaluateUnsupportedExpression(expressionEngine => expressionEngine.GetValue(AdaptiveCardExpression.Variable(PropertyPath.TopicVariable(Variables.StringValue)), this.Scopes.BuildState()));
-    }
-
-    [Fact]
-    public void DialogExpressionGetValueUnsupported()
-    {
-        this.EvaluateUnsupportedExpression(expressionEngine => expressionEngine.GetValue(DialogExpression.Variable(PropertyPath.TopicVariable(Variables.StringValue)), this.Scopes.BuildState()));
-    }
-
-    [Fact]
-    public void FileExpressionGetValueUnsupported()
-    {
-        this.EvaluateUnsupportedExpression(expressionEngine => expressionEngine.GetValue(FileExpression.Variable(PropertyPath.TopicVariable(Variables.StringValue)), this.Scopes.BuildState()));
-    }
-
-    #endregion
-
     #region BoolExpression Tests
 
     [Fact]
@@ -101,16 +78,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: false);
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void BoolExpressionGetValueForVariable(bool useState)
+    [Fact]
+    public void BoolExpressionGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression(
             BoolExpression.Variable(PropertyPath.TopicVariable(Variables.BoolValue)),
-            expectedValue: true,
-            useState);
+            expectedValue: true);
     }
 
     [Fact]
@@ -158,16 +132,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: "test");
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void StringExpressionGetValueForVariable(bool useState)
+    [Fact]
+    public void StringExpressionGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression(
             StringExpression.Variable(PropertyPath.TopicVariable(Variables.StringValue)),
-            expectedValue: "Hello World",
-            useState);
+            expectedValue: "Hello World");
     }
 
     [Fact]
@@ -184,7 +155,7 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
     {
         // Arrange
         RecordValue state = FormulaValue.NewRecordFromFields([new NamedValue("test", FormulaValue.New("value"))]);
-        this.Scopes.Set("TestRecord", state, VariableScopeNames.Global);
+        this.State.Set("TestRecord", state, VariableScopeNames.Global);
 
         // Arrange, Act & Assert
         this.EvaluateExpression(
@@ -233,16 +204,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: 7);
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void IntExpressionGetValueForVariable(bool useState)
+    [Fact]
+    public void IntExpressionGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression(
             IntExpression.Variable(PropertyPath.TopicVariable(Variables.IntValue)),
-            expectedValue: long.MaxValue,
-            useState);
+            expectedValue: long.MaxValue);
     }
 
     [Fact]
@@ -337,16 +305,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: DataValue.Create("test"));
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void DataValueExpressionGetValueForVariable(bool useState)
+    [Fact]
+    public void DataValueExpressionGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression(
             ValueExpression.Variable(PropertyPath.TopicVariable(Variables.StringValue)),
-            expectedValue: DataValue.Create("Hello World"),
-            useState);
+            expectedValue: DataValue.Create("Hello World"));
     }
 
     [Fact]
@@ -394,16 +359,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: VariablesToClear.ConversationScopedVariables);
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void EnumExpressionGetValueForVariable(bool useState)
+    [Fact]
+    public void EnumExpressionGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression<VariablesToClearWrapper>(
             EnumExpression<VariablesToClearWrapper>.Variable(PropertyPath.TopicVariable(Variables.EnumValue)),
-            expectedValue: VariablesToClear.ConversationScopedVariables,
-            useState);
+            expectedValue: VariablesToClear.ConversationScopedVariables);
     }
 
     [Fact]
@@ -455,16 +417,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: null);
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void ObjectExpressionGetValueForVariable(bool useState)
+    [Fact]
+    public void ObjectExpressionGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression(
             ObjectExpression<RecordDataValue>.Variable(PropertyPath.TopicVariable(Variables.ObjectValue)),
-            expectedValue: ObjectData.ToRecord(),
-            useState);
+            expectedValue: ObjectData.ToRecord());
     }
 
     #endregion
@@ -504,16 +463,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: []);
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void ArrayExpressionGetValueForVariable(bool useState)
+    [Fact]
+    public void ArrayExpressionGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression(
             ArrayExpression<string>.Variable(PropertyPath.TopicVariable(Variables.ArrayValue)),
-            expectedValue: ["a", "b"],
-            useState);
+            expectedValue: ["a", "b"]);
     }
 
     [Fact]
@@ -552,16 +508,13 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
             expectedValue: []);
     }
 
-    [Theory]
-    [InlineData(false)]
-    [InlineData(true)]
-    public void ArrayExpressionOnlyGetValueForVariable(bool useState)
+    [Fact]
+    public void ArrayExpressionOnlyGetValueForVariable()
     {
         // Arrange, Act & Assert
         this.EvaluateExpression(
             ArrayExpressionOnly<string>.Variable(PropertyPath.TopicVariable(Variables.ArrayValue)),
-            expectedValue: ["a", "b"],
-            useState);
+            expectedValue: ["a", "b"]);
     }
 
     [Fact]
@@ -575,85 +528,80 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
 
     #endregion
 
-    private EvaluationResult<bool> EvaluateExpression(BoolExpression expression, bool expectedValue, bool useState = false, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
-        => this.EvaluateExpression((evaluator) => useState ? evaluator.GetValue(expression, this.Scopes) : evaluator.GetValue(expression, this.Scopes.BuildState()), expectedValue, expectedSensitivity);
+    private EvaluationResult<bool> EvaluateExpression(BoolExpression expression, bool expectedValue, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
+        => this.EvaluateExpression((evaluator) => evaluator.GetValue(expression), expectedValue, expectedSensitivity);
 
     private void EvaluateInvalidExpression<TException>(BoolExpression expression)
         where TException : Exception
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression));
 
-    private EvaluationResult<string> EvaluateExpression(StringExpression expression, string expectedValue, bool useState = false, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
-        => this.EvaluateExpression((evaluator) => useState ? evaluator.GetValue(expression, this.Scopes) : evaluator.GetValue(expression, this.Scopes.BuildState()), expectedValue, expectedSensitivity);
+    private EvaluationResult<string> EvaluateExpression(StringExpression expression, string expectedValue, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
+        => this.EvaluateExpression((evaluator) => evaluator.GetValue(expression), expectedValue, expectedSensitivity);
 
     private void EvaluateInvalidExpression<TException>(StringExpression expression)
         where TException : Exception
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression));
 
-    private EvaluationResult<long> EvaluateExpression(IntExpression expression, long expectedValue, bool useState = false, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
-        => this.EvaluateExpression((evaluator) => useState ? evaluator.GetValue(expression, this.Scopes) : evaluator.GetValue(expression, this.Scopes.BuildState()), expectedValue, expectedSensitivity);
+    private EvaluationResult<long> EvaluateExpression(IntExpression expression, long expectedValue, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
+        => this.EvaluateExpression((evaluator) => evaluator.GetValue(expression), expectedValue, expectedSensitivity);
 
     private void EvaluateInvalidExpression<TException>(IntExpression expression)
         where TException : Exception
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression));
 
-    private EvaluationResult<double> EvaluateExpression(NumberExpression expression, double expectedValue, bool useState = false, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
-        => this.EvaluateExpression((evaluator) => useState ? evaluator.GetValue(expression, this.Scopes) : evaluator.GetValue(expression, this.Scopes.BuildState()), expectedValue, expectedSensitivity);
+    private EvaluationResult<double> EvaluateExpression(NumberExpression expression, double expectedValue, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
+        => this.EvaluateExpression((evaluator) => evaluator.GetValue(expression), expectedValue, expectedSensitivity);
 
     private void EvaluateInvalidExpression<TException>(NumberExpression expression)
         where TException : Exception
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression));
 
-    private EvaluationResult<DataValue> EvaluateExpression(ValueExpression expression, DataValue expectedValue, bool useState = false, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
-        => this.EvaluateExpression((evaluator) => useState ? evaluator.GetValue(expression, this.Scopes) : evaluator.GetValue(expression, this.Scopes.BuildState()), expectedValue, expectedSensitivity);
+    private EvaluationResult<DataValue> EvaluateExpression(ValueExpression expression, DataValue expectedValue, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
+        => this.EvaluateExpression((evaluator) => evaluator.GetValue(expression), expectedValue, expectedSensitivity);
 
     private void EvaluateInvalidExpression<TException>(ValueExpression expression)
         where TException : Exception
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue(expression));
 
-    private EvaluationResult<TEnum> EvaluateExpression<TEnum>(EnumExpression<TEnum> expression, TEnum expectedValue, bool useState = false, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
+    private EvaluationResult<TEnum> EvaluateExpression<TEnum>(EnumExpression<TEnum> expression, TEnum expectedValue, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
         where TEnum : EnumWrapper
-        => this.EvaluateExpression((evaluator) => useState ? evaluator.GetValue<TEnum>(expression, this.Scopes) : evaluator.GetValue<TEnum>(expression, this.Scopes.BuildState()), expectedValue, expectedSensitivity);
+        => this.EvaluateExpression((evaluator) => evaluator.GetValue<TEnum>(expression), expectedValue, expectedSensitivity);
 
     private void EvaluateInvalidExpression<TEnum, TException>(EnumExpression<TEnum> expression)
         where TException : Exception
         where TEnum : EnumWrapper
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TEnum>(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TEnum>(expression));
 
-    private EvaluationResult<TValue?> EvaluateExpression<TValue>(ObjectExpression<TValue> expression, TValue? expectedValue, bool useState = false, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
+    private EvaluationResult<TValue?> EvaluateExpression<TValue>(ObjectExpression<TValue> expression, TValue? expectedValue, SensitivityLevel expectedSensitivity = SensitivityLevel.None)
         where TValue : BotElement
-        => this.EvaluateExpression((evaluator) => useState ? evaluator.GetValue<TValue>(expression, this.Scopes) : evaluator.GetValue<TValue>(expression, this.Scopes.BuildState()), expectedValue, expectedSensitivity);
+        => this.EvaluateExpression((evaluator) => evaluator.GetValue<TValue>(expression), expectedValue, expectedSensitivity);
 
     private void EvaluateInvalidExpression<TValue, TException>(ObjectExpression<TValue> expression)
         where TException : Exception
         where TValue : BotElement
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TValue>(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TValue>(expression));
 
-    private ImmutableArray<TValue> EvaluateExpression<TValue>(ArrayExpression<TValue> expression, TValue[] expectedValue, bool useState = false)
-        => this.EvaluateArrayExpression((evaluator) => useState ? evaluator.GetValue<TValue>(expression, this.Scopes) : evaluator.GetValue<TValue>(expression, this.Scopes.BuildState()), expectedValue);
+    private ImmutableArray<TValue> EvaluateExpression<TValue>(ArrayExpression<TValue> expression, TValue[] expectedValue)
+        => this.EvaluateArrayExpression((evaluator) => evaluator.GetValue<TValue>(expression), expectedValue);
 
     private void EvaluateInvalidExpression<TValue, TException>(ArrayExpression<TValue> expression)
         where TException : Exception
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TValue>(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TValue>(expression));
 
-    private ImmutableArray<TValue> EvaluateExpression<TValue>(ArrayExpressionOnly<TValue> expression, TValue[] expectedValue, bool useState = false)
-        => this.EvaluateArrayExpression((evaluator) => useState ? evaluator.GetValue<TValue>(expression, this.Scopes) : evaluator.GetValue<TValue>(expression, this.Scopes.BuildState()), expectedValue);
+    private ImmutableArray<TValue> EvaluateExpression<TValue>(ArrayExpressionOnly<TValue> expression, TValue[] expectedValue)
+        => this.EvaluateArrayExpression((evaluator) => evaluator.GetValue<TValue>(expression), expectedValue);
 
     private void EvaluateInvalidExpression<TValue, TException>(ArrayExpressionOnly<TValue> expression)
         where TException : Exception
-        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TValue>(expression, this.Scopes));
+        => this.EvaluateInvalidExpression<TException>((evaluator) => evaluator.GetValue<TValue>(expression));
 
     private EvaluationResult<TValue> EvaluateExpression<TValue>(
         Func<WorkflowExpressionEngine, EvaluationResult<TValue>> evaluator,
         TValue? expectedValue,
         SensitivityLevel expectedSensitivity = SensitivityLevel.None)
     {
-        // Arrange
-        RecalcEngine engine = this.CreateEngine();
-        this.Scopes.Bind(engine);
-        WorkflowExpressionEngine expressionEngine = new(engine);
-
         // Act
-        EvaluationResult<TValue> result = evaluator.Invoke(expressionEngine);
+        EvaluationResult<TValue> result = evaluator.Invoke(this.State.Evaluator);
 
         // Assert
         Assert.Equal(expectedValue, result.Value);
@@ -666,13 +614,8 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
         Func<WorkflowExpressionEngine, ImmutableArray<TValue>> evaluator,
         TValue[] expectedValue)
     {
-        // Arrange
-        RecalcEngine engine = this.CreateEngine();
-        this.Scopes.Bind(engine);
-        WorkflowExpressionEngine expressionEngine = new(engine);
-
         // Act
-        ImmutableArray<TValue> result = evaluator.Invoke(expressionEngine);
+        ImmutableArray<TValue> result = evaluator.Invoke(this.State.Evaluator);
 
         // Assert
         Assert.Equal(expectedValue.Length, result.Length);
@@ -683,23 +626,7 @@ public class WorkflowExpressionEngineTests : RecalcEngineTest
 
     private void EvaluateInvalidExpression<TException>(Action<WorkflowExpressionEngine> evaluator) where TException : Exception
     {
-        // Arrange
-        RecalcEngine engine = this.CreateEngine();
-        this.Scopes.Bind(engine);
-        WorkflowExpressionEngine expressionEngine = new(engine);
-
-        // Act
-        Assert.Throws<TException>(() => evaluator.Invoke(expressionEngine));
-    }
-
-    private void EvaluateUnsupportedExpression(Action<WorkflowExpressionEngine> evaluator)
-    {
-        // Arrange
-        RecalcEngine engine = this.CreateEngine();
-        this.Scopes.Bind(engine);
-        WorkflowExpressionEngine expressionEngine = new(engine);
-
-        // Act
-        Assert.Throws<NotSupportedException>(() => evaluator.Invoke(expressionEngine));
+        // Act & Assert
+        Assert.Throws<TException>(() => evaluator.Invoke(this.State.Evaluator));
     }
 }

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/PowerFx/WorkflowScopesTests.cs

@@ -9,17 +9,16 @@ namespace Microsoft.Agents.Workflows.Declarative.UnitTests.PowerFx;
 
 public class WorkflowScopesTests
 {
+    internal WorkflowFormulaState State { get; } = new(RecalcEngineFactory.Create());
+
     [Fact]
     public void ConstructorInitializesAllScopes()
     {
-        // Arrange & Act
-        WorkflowScopes scopes = new();
-
-        // Assert
-        RecordValue envRecord = scopes.BuildRecord(VariableScopeNames.Environment);
-        RecordValue topicRecord = scopes.BuildRecord(VariableScopeNames.Topic);
-        RecordValue globalRecord = scopes.BuildRecord(VariableScopeNames.Global);
-        RecordValue systemRecord = scopes.BuildRecord(VariableScopeNames.System);
+        // Act & Assert
+        RecordValue envRecord = this.State.BuildRecord(VariableScopeNames.Environment);
+        RecordValue topicRecord = this.State.BuildRecord(VariableScopeNames.Topic);
+        RecordValue globalRecord = this.State.BuildRecord(VariableScopeNames.Global);
+        RecordValue systemRecord = this.State.BuildRecord(VariableScopeNames.System);
 
         Assert.NotNull(envRecord);
         Assert.NotNull(topicRecord);
@@ -30,11 +29,8 @@ public class WorkflowScopesTests
     [Fact]
     public void BuildRecordWhenEmpty()
     {
-        // Arrange
-        WorkflowScopes scopes = new();
-
         // Act
-        RecordValue record = scopes.BuildRecord(VariableScopeNames.Topic);
+        RecordValue record = this.State.BuildRecord(VariableScopeNames.Topic);
 
         // Assert
         Assert.NotNull(record);
@@ -45,12 +41,11 @@ public class WorkflowScopesTests
     public void BuildRecordContainsSetValues()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue testValue = FormulaValue.New("test");
-        scopes.Set("key1", testValue, VariableScopeNames.Topic);
+        this.State.Set("key1", testValue, VariableScopeNames.Topic);
 
         // Act
-        RecordValue record = scopes.BuildRecord(VariableScopeNames.Topic);
+        RecordValue record = this.State.BuildRecord(VariableScopeNames.Topic);
 
         // Assert
         Assert.NotNull(record);
@@ -63,24 +58,23 @@ public class WorkflowScopesTests
     public void BuildRecordForAllScopeTypes()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue testValue = FormulaValue.New("test");
 
         // Act & Assert
-        scopes.Set("envKey", testValue, VariableScopeNames.Environment);
-        RecordValue envRecord = scopes.BuildRecord(VariableScopeNames.Environment);
+        this.State.Set("envKey", testValue, VariableScopeNames.Environment);
+        RecordValue envRecord = this.State.BuildRecord(VariableScopeNames.Environment);
         Assert.Single(envRecord.Fields);
 
-        scopes.Set("topicKey", testValue, VariableScopeNames.Topic);
-        RecordValue topicRecord = scopes.BuildRecord(VariableScopeNames.Topic);
+        this.State.Set("topicKey", testValue, VariableScopeNames.Topic);
+        RecordValue topicRecord = this.State.BuildRecord(VariableScopeNames.Topic);
         Assert.Single(topicRecord.Fields);
 
-        scopes.Set("globalKey", testValue, VariableScopeNames.Global);
-        RecordValue globalRecord = scopes.BuildRecord(VariableScopeNames.Global);
+        this.State.Set("globalKey", testValue, VariableScopeNames.Global);
+        RecordValue globalRecord = this.State.BuildRecord(VariableScopeNames.Global);
         Assert.Single(globalRecord.Fields);
 
-        scopes.Set("systemKey", testValue, VariableScopeNames.System);
-        RecordValue systemRecord = scopes.BuildRecord(VariableScopeNames.System);
+        this.State.Set("systemKey", testValue, VariableScopeNames.System);
+        RecordValue systemRecord = this.State.BuildRecord(VariableScopeNames.System);
         Assert.Single(systemRecord.Fields);
     }
 
@@ -88,12 +82,11 @@ public class WorkflowScopesTests
     public void GetWithImplicitScope()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue testValue = FormulaValue.New("test");
-        scopes.Set("key1", testValue, VariableScopeNames.Topic);
+        this.State.Set("key1", testValue, VariableScopeNames.Topic);
 
         // Act
-        FormulaValue result = scopes.Get("key1");
+        FormulaValue result = this.State.Get("key1");
 
         // Assert
         Assert.Equal(testValue, result);
@@ -103,12 +96,11 @@ public class WorkflowScopesTests
     public void GetWithSpecifiedScope()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue testValue = FormulaValue.New("test");
-        scopes.Set("key1", testValue, VariableScopeNames.Global);
+        this.State.Set("key1", testValue, VariableScopeNames.Global);
 
         // Act
-        FormulaValue result = scopes.Get("key1", VariableScopeNames.Global);
+        FormulaValue result = this.State.Get("key1", VariableScopeNames.Global);
 
         // Assert
         Assert.Equal(testValue, result);
@@ -118,14 +110,13 @@ public class WorkflowScopesTests
     public void SetDefaultScope()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue testValue = FormulaValue.New("test");
 
         // Act
-        scopes.Set("key1", testValue);
+        this.State.Set("key1", testValue);
 
         // Assert
-        FormulaValue result = scopes.Get("key1", VariableScopeNames.Topic);
+        FormulaValue result = this.State.Get("key1", VariableScopeNames.Topic);
         Assert.Equal(testValue, result);
     }
 
@@ -133,14 +124,13 @@ public class WorkflowScopesTests
     public void SetSpecifiedScope()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue testValue = FormulaValue.New("test");
 
         // Act
-        scopes.Set("key1", testValue, VariableScopeNames.System);
+        this.State.Set("key1", testValue, VariableScopeNames.System);
 
         // Assert
-        FormulaValue result = scopes.Get("key1", VariableScopeNames.System);
+        FormulaValue result = this.State.Get("key1", VariableScopeNames.System);
         Assert.Equal(testValue, result);
     }
 
@@ -148,16 +138,15 @@ public class WorkflowScopesTests
     public void SetOverwritesExistingValue()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue initialValue = FormulaValue.New("initial");
         FormulaValue newValue = FormulaValue.New("new");
 
         // Act
-        scopes.Set("key1", initialValue, VariableScopeNames.Topic);
-        scopes.Set("key1", newValue, VariableScopeNames.Topic);
+        this.State.Set("key1", initialValue, VariableScopeNames.Topic);
+        this.State.Set("key1", newValue, VariableScopeNames.Topic);
 
         // Assert
-        FormulaValue result = scopes.Get("key1", VariableScopeNames.Topic);
+        FormulaValue result = this.State.Get("key1", VariableScopeNames.Topic);
         Assert.Equal(newValue, result);
     }
 
@@ -165,21 +154,20 @@ public class WorkflowScopesTests
     public void RemoveSpecifiedScope()
     {
         // Arrange
-        WorkflowScopes scopes = new();
         FormulaValue testValue = FormulaValue.New("test");
 
         // Act
-        scopes.Set("key1", testValue);
+        this.State.Set("key1", testValue);
 
         // Assert
-        FormulaValue result = scopes.Get("key1");
+        FormulaValue result = this.State.Get("key1");
         Assert.Equal(testValue, result);
 
         // Act
-        scopes.Reset("key1");
+        this.State.Reset("key1");
 
         // Assert
-        FormulaValue resultBlank = scopes.Get("key1");
+        FormulaValue resultBlank = this.State.Get("key1");
         Assert.IsType<BlankValue>(resultBlank);
     }
 }

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/Workflows/Condition.yaml

@@ -9,7 +9,7 @@ beginDialog:
     - kind: SetVariable
       id: setVariable_test
       variable: Topic.TestValue
-      value: =Value(System.LastMessage.Text)
+      value: =System.LastMessageText
 
     - kind: ConditionGroup
       id: conditionGroup_test

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/Workflows/ConditionElse.yaml

@@ -9,7 +9,7 @@ beginDialog:
     - kind: SetVariable
       id: setVariable_test
       variable: Topic.TestValue
-      value: =Value(System.LastMessage.Text)
+      value: =System.LastMessageText
 
     - kind: ConditionGroup
       id: conditionGroup_test

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/Workflows/Goto.yaml

@@ -10,15 +10,15 @@ beginDialog:
       actionId: end_all
 
     - kind: SendActivity
-      id: sendActivity_1
+      id: send_activity_1
       activity: NEVER 1!
       
     - kind: SendActivity
-      id: sendActivity_2
+      id: send_activity_2
       activity: NEVER 2!
 
     - kind: SendActivity
-      id: sendActivity_3
+      id: send_activity_3
       activity: NEVER 3!
 
     - kind: EndConversation

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/Workflows/SendActivity.yaml

@@ -0,0 +1,16 @@
+kind: AdaptiveDialog
+beginDialog:
+  kind: OnActivity
+  id: my_workflow
+  type: Message
+  actions:
+  
+    - kind: SetVariable
+      id: set_input
+      variable: Topic.TestValue
+      value: =System.LastMessageText
+
+    - kind: SendActivity
+      id: activity_input
+      activity: |-
+        Input: {Topic.TestValue}

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/Workflows/SetTextVariable.yaml

@@ -7,4 +7,4 @@ beginDialog:
     - kind: SetTextVariable
       id: set_text
       variable: Topic.TestVar
-      value: "Test content"
+      value: Test content

dotnet/tests/Microsoft.Agents.Workflows.Declarative.UnitTests/Workflows/SetVariable.yaml

@@ -0,0 +1,10 @@
+kind: AdaptiveDialog
+beginDialog:
+  kind: OnActivity
+  id: my_workflow
+  type: Message
+  actions:
+    - kind: SetVariable
+      id: set_var
+      variable: Topic.TestVar
+      value: =3

workflows/HumanInLoop.yaml

@@ -29,16 +29,29 @@ beginDialog:
       entity:
         kind: StringPrebuiltEntity
 
-    # Respond with input
-    - kind: SendActivity
-      id: sendActivity_input
-      activity: |-
-        You entered:
-        {Topic.OriginalInput}
+    - kind: ConditionGroup
+      id: check_completion
+      conditions:
 
-        Confirmed input:
-        {Topic.ConfirmedInput}
+        - condition: =Topic.OriginalInput <> Topic.ConfirmedInput
+          id: check_confirm
+          actions:
 
+            - kind: SendActivity
+              id: sendActivity_mismatch
+              activity: |-
+                "{Topic.ConfirmedInput}" does not match the original input of "{Topic.OriginalInput}". Please try again.
 
+            - kind: GotoAction
+              id: goto_again
+              actionId: question_confirm
 
+      elseActions: # // %%% REMOVE / BUG
+        - kind: SendActivity
+          id: sendActivity_confirmed
+          activity: |-
+            You entered:
+            {Topic.OriginalInput}
 
+            Confirmed input:
+            {Topic.ConfirmedInput}

workflows/MathChat.yaml

@@ -34,7 +34,7 @@ beginDialog:
     - kind: SetVariable
       id: set_project
       variable: Topic.Project
-      value: =System.LastMessageText
+      value: =System.LastMessage.Text
 
     - kind: InvokeAzureAgent
       id: question_student
@@ -43,8 +43,6 @@ beginDialog:
         name: =Env.FOUNDRY_AGENT_STUDENT
       input:
         messages: =[UserMessage(Topic.Project)]
-      output:
-        messages: Topic.Answer
 
     - kind: ResetVariable
       id: reset_project
@@ -55,6 +53,8 @@ beginDialog:
       conversationId: =System.ConversationId
       agent:
         name: =Env.FOUNDRY_AGENT_TEACHER
+      output:
+        messages: Topic.TeacherResponse
 
     - kind: SetVariable
       id: set_count_increment
@@ -65,7 +65,7 @@ beginDialog:
       id: check_completion
       conditions:
 
-        - condition: =!IsBlank(Find("congratulations", Lower(System.LastMessageText)))
+        - condition: =!IsBlank(Find("CONGRATULATIONS", Upper(Topic.TeacherResponse.Text)))
           id: check_turn_done
           actions: