.Net: Removing IsSemantic and IsAsync properties from ISKFunction and…

… FunctionView (microsoft#2881)

### Motivation and Context
The Kernel no longer differentiates between Native and Semantic
functions, nor between async and synchronous functions. These are
abstractions that are resolved internally.

### Description
ISKFunction
 - Removing IsSemantic
 - Updating tests and callers

FunctionView
 - Removing IsSemantic
 - Removing IsAsync
 - Updating tests and callers

### Contribution Checklist
- [X] The code builds clean without any errors or warnings
- [X] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [X] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄
   BREAKING CHANGE - due to change in public APIs. Low impact.

---------

Co-authored-by: Mark Wallace <127216156+markwallace-microsoft@users.noreply.github.com>

dotnet/src/Extensions/Extensions.UnitTests/Planning/ActionPlanner/ActionPlannerTests.cs

@@ -204,7 +204,7 @@ private Mock<ISkillCollection> CreateMockSkillCollection()
         var skills = new Mock<ISkillCollection>();
         foreach (var (name, skillName, description, isSemantic) in functions)
         {
-            var functionView = new FunctionView(name, skillName, description, new List<ParameterView>(), isSemantic, true);
+            var functionView = new FunctionView(name, skillName, description);
             var mockFunction = CreateMockFunction(functionView);
             functionsView.Add(functionView);
 

dotnet/src/Extensions/Extensions.UnitTests/Planning/SequentialPlanner/SKContextExtensionsTests.cs

@@ -68,8 +68,8 @@ public async Task CanCallGetAvailableFunctionsWithFunctionsAsync()
 
         // Arrange FunctionView
         var functionMock = new Mock<ISKFunction>();
-        var functionView = new FunctionView("functionName", "skillName", "description", new List<ParameterView>(), true, false);
-        var nativeFunctionView = new FunctionView("nativeFunctionName", "skillName", "description", new List<ParameterView>(), false, false);
+        var functionView = new FunctionView("functionName", "skillName", "description");
+        var nativeFunctionView = new FunctionView("nativeFunctionName", "skillName", "description");
         var functionsView = new List<FunctionView>() { functionView, nativeFunctionView };
 
         // Arrange Mock Memory and Result
@@ -133,8 +133,8 @@ public async Task CanCallGetAvailableFunctionsWithFunctionsWithRelevancyAsync()
 
         // Arrange FunctionView
         var functionMock = new Mock<ISKFunction>();
-        var functionView = new FunctionView("functionName", "skillName", "description", new List<ParameterView>(), true, false);
-        var nativeFunctionView = new FunctionView("nativeFunctionName", "skillName", "description", new List<ParameterView>(), false, false);
+        var functionView = new FunctionView("functionName", "skillName", "description");
+        var nativeFunctionView = new FunctionView("nativeFunctionName", "skillName", "description");
         var functionsView = new List<FunctionView>() { functionView, nativeFunctionView };
 
         // Arrange Mock Memory and Result

dotnet/src/Extensions/Extensions.UnitTests/Planning/SequentialPlanner/SequentialPlanParserTests.cs

@@ -66,7 +66,10 @@ private static Mock<ISKFunction> CreateMockFunction(FunctionView functionView, s
         var functionsView = new List<FunctionView>();
         foreach (var (name, skillName, description, isSemantic, resultString) in functions)
         {
-            var functionView = new FunctionView(name, skillName, description, new List<ParameterView>() { new(name: "param", description: "description") }, isSemantic, true);
+            var functionView = new FunctionView(name, skillName, description)
+            {
+                Parameters = new ParameterView[] { new("param", "description") }
+            };
             var mockFunction = CreateMockFunction(functionView);
             functionsView.Add(functionView);
 

dotnet/src/Extensions/Extensions.UnitTests/Planning/SequentialPlanner/SequentialPlannerTests.cs

@@ -38,7 +38,7 @@ public async Task ItCanCreatePlanAsync(string goal)
         var skills = new Mock<ISkillCollection>();
         foreach (var (name, skillName, description, isSemantic) in input)
         {
-            var functionView = new FunctionView(name, skillName, description, new List<ParameterView>(), isSemantic, true);
+            var functionView = new FunctionView(name, skillName, description);
             var mockFunction = CreateMockFunction(functionView);
             functionsView.Add(functionView);
 

dotnet/src/Functions/Functions.Grpc/Extensions/GrpcOperationExtensions.cs

@@ -21,7 +21,7 @@ internal static class GrpcOperationExtensions
     /// <returns>The list of parameters.</returns>
     public static IReadOnlyList<ParameterView> GetParameters(this GrpcOperation operation)
     {
-        var parameters = new List<ParameterView>
+        var parameters = new ParameterView[]
         {
             // Register the "address" parameter so that it's possible to override it if needed.
             new ParameterView(GrpcOperation.AddressArgumentName,

dotnet/src/Functions/Functions.OpenAPI/Extensions/KernelAIPluginExtensions.cs

@@ -380,9 +380,8 @@ async Task<SKContext> ExecuteAsync(SKContext context)
         }
 
         var parameters = restOperationParameters
-            .Select(p => new ParameterView
+            .Select(p => new ParameterView(p.AlternativeName ?? p.Name)
             {
-                Name = p.AlternativeName ?? p.Name,
                 Description = $"{p.Description ?? p.Name}{(p.IsRequired ? " (required)" : string.Empty)}",
                 DefaultValue = p.DefaultValue ?? string.Empty,
                 Type = string.IsNullOrEmpty(p.Type) ? null : new ParameterViewType(p.Type),

dotnet/src/InternalUtilities/src/Diagnostics/IsExternalInit.cs

@@ -0,0 +1,14 @@
+// Copyright (c) Microsoft. All rights reserved.
+
+using System.ComponentModel;
+
+namespace System.Runtime.CompilerServices;
+
+/// <summary>
+/// Reserved to be used by the compiler for tracking metadata.
+/// This class should not be used by developers in source code.
+/// </summary>
+[EditorBrowsable(EditorBrowsableState.Never)]
+internal static class IsExternalInit
+{
+}

dotnet/src/InternalUtilities/src/Diagnostics/Verify.cs

@@ -84,7 +84,7 @@ internal static void DirectoryExists(string path)
     /// Make sure every function parameter name is unique
     /// </summary>
     /// <param name="parameters">List of parameters</param>
-    internal static void ParametersUniqueness(IList<ParameterView> parameters)
+    internal static void ParametersUniqueness(IReadOnlyList<ParameterView> parameters)
     {
         int count = parameters.Count;
         if (count > 0)

dotnet/src/SemanticKernel.Abstractions/SemanticFunctions/IPromptTemplate.cs

@@ -14,10 +14,9 @@ namespace Microsoft.SemanticKernel.SemanticFunctions;
 public interface IPromptTemplate
 {
     /// <summary>
-    /// Get the list of parameters required by the template, using configuration and template info.
+    /// The list of parameters required by the template, using configuration and template info.
     /// </summary>
-    /// <returns>List of parameters</returns>
-    IList<ParameterView> GetParameters();
+    IReadOnlyList<ParameterView> Parameters { get; }
 
     /// <summary>
     /// Render the template using the information in the context

dotnet/src/SemanticKernel.Abstractions/SkillDefinition/FunctionView.cs

@@ -1,79 +1,25 @@
 // Copyright (c) Microsoft. All rights reserved.
 
+using System;
 using System.Collections.Generic;
-using System.Diagnostics;
 
 namespace Microsoft.SemanticKernel.SkillDefinition;
 
 /// <summary>
-/// Class used to copy and export data from the skill collection.
-/// The data is mutable, but changes do not affect the skill collection.
+/// A function view is a read-only representation of a function.
 /// </summary>
-[DebuggerDisplay("{DebuggerDisplay,nq}")]
-public sealed class FunctionView
+/// <param name="Name">Name of the function. The name is used by the skill collection and in prompt templates e.g. {{skillName.functionName}}</param>
+/// <param name="SkillName">Name of the skill containing the function. The name is used by the skill collection and in prompt templates e.g. {{skillName.functionName}}</param>
+/// <param name="Description">Function description. The description is used in combination with embeddings when searching relevant functions.</param>
+/// <param name="Parameters">Optional list of function parameters</param>
+public sealed record FunctionView(
+    string Name,
+    string SkillName,
+    string Description = "",
+    IReadOnlyList<ParameterView>? Parameters = null)
 {
-    /// <summary>
-    /// Name of the function. The name is used by the skill collection and in prompt templates e.g. {{skillName.functionName}}
-    /// </summary>
-    public string Name { get; set; } = string.Empty;
-
-    /// <summary>
-    /// Name of the skill containing the function. The name is used by the skill collection and in prompt templates e.g. {{skillName.functionName}}
-    /// </summary>
-    public string SkillName { get; set; } = string.Empty;
-
-    /// <summary>
-    /// Function description. The description is used in combination with embeddings when searching relevant functions.
-    /// </summary>
-    public string Description { get; set; } = string.Empty;
-
-    /// <summary>
-    /// Whether the delegate points to a semantic function
-    /// </summary>
-    public bool IsSemantic { get; set; }
-
-    /// <summary>
-    /// Whether the delegate is an asynchronous function
-    /// </summary>
-    public bool IsAsynchronous { get; set; }
-
     /// <summary>
     /// List of function parameters
     /// </summary>
-    public IList<ParameterView> Parameters { get; set; } = new List<ParameterView>();
-
-    /// <summary>
-    /// Constructor
-    /// </summary>
-    public FunctionView()
-    {
-    }
-
-    /// <summary>
-    /// Create a function view.
-    /// </summary>
-    /// <param name="name">Function name</param>
-    /// <param name="skillName">Skill name, e.g. the function namespace</param>
-    /// <param name="description">Function description</param>
-    /// <param name="parameters">List of function parameters provided by the skill developer</param>
-    /// <param name="isSemantic">Whether the function is a semantic one (or native is False)</param>
-    /// <param name="isAsynchronous">Whether the function is async. Note: all semantic functions are async.</param>
-    public FunctionView(
-        string name,
-        string skillName,
-        string description,
-        IList<ParameterView> parameters,
-        bool isSemantic,
-        bool isAsynchronous = true)
-    {
-        this.Name = name;
-        this.SkillName = skillName;
-        this.Description = description;
-        this.Parameters = parameters;
-        this.IsSemantic = isSemantic;
-        this.IsAsynchronous = isAsynchronous;
-    }
-
-    [DebuggerBrowsable(DebuggerBrowsableState.Never)]
-    private string DebuggerDisplay => $"{this.Name} ({this.Description})";
+    public IReadOnlyList<ParameterView> Parameters { get; init; } = Parameters ?? Array.Empty<ParameterView>();
 }

dotnet/src/SemanticKernel.Abstractions/SkillDefinition/ISKFunction.cs

@@ -1,6 +1,7 @@
 // Copyright (c) Microsoft. All rights reserved.
 
 using System;
+using System.ComponentModel;
 using System.Threading;
 using System.Threading.Tasks;
 using Microsoft.SemanticKernel.AI;
@@ -29,13 +30,6 @@ public interface ISKFunction
     /// </summary>
     string Description { get; }
 
-    /// <summary>
-    /// Whether the function is defined using a prompt template.
-    /// IMPORTANT: native functions might use semantic functions internally,
-    /// so when this property is False, executing the function might still involve AI calls.
-    /// </summary>
-    bool IsSemantic { get; }
-
     /// <summary>
     /// AI service settings
     /// </summary>
@@ -81,4 +75,17 @@ public interface ISKFunction
     /// <param name="requestSettings">LLM completion settings</param>
     /// <returns>Self instance</returns>
     ISKFunction SetAIConfiguration(AIRequestSettings? requestSettings);
+
+    #region Obsolete
+
+    /// <summary>
+    /// Whether the function is defined using a prompt template.
+    /// IMPORTANT: native functions might use semantic functions internally,
+    /// so when this property is False, executing the function might still involve AI calls.
+    /// </summary>
+    [Obsolete("Kernel no longer differentiates between Semantic and Native functions. This will be removed in a future release.")]
+    [EditorBrowsable(EditorBrowsableState.Never)]
+    bool IsSemantic { get; }
+
+    #endregion
 }

dotnet/src/SemanticKernel.Abstractions/SkillDefinition/ParameterView.cs

@@ -1,75 +1,16 @@
 // Copyright (c) Microsoft. All rights reserved.
 
-using System.Diagnostics;
-using Microsoft.SemanticKernel.Diagnostics;
-
 namespace Microsoft.SemanticKernel.SkillDefinition;
 
 /// <summary>
-/// Class used to copy and export data about parameters
-/// for planner and related scenarios.
+/// Class used to copy and export data about parameters for planner and related scenarios.
 /// </summary>
-[DebuggerDisplay("{DebuggerDisplay,nq}")]
-public sealed class ParameterView
-{
-    private string _name = string.Empty;
-
-    /// <summary>
-    /// Parameter name. Alphanumeric chars + "_" only.
-    /// </summary>
-    public string Name
-    {
-        get => this._name;
-        set
-        {
-            Verify.ValidFunctionParamName(value);
-            this._name = value;
-        }
-    }
-
-    /// <summary>
-    /// Parameter description.
-    /// </summary>
-    public string? Description { get; set; }
-
-    /// <summary>
-    /// Default value when the value is not provided.
-    /// </summary>
-    public string? DefaultValue { get; set; }
-
-    /// <summary>
-    /// Parameter type.
-    /// </summary>
-    public ParameterViewType? Type { get; set; }
-
-    /// <summary>
-    /// Constructor
-    /// </summary>
-    public ParameterView()
-    {
-    }
-
-    /// <summary>
-    /// Create a function parameter view, using information provided by the skill developer.
-    /// </summary>
-    /// <param name="name">Parameter name. The name must be alphanumeric (underscore is the only special char allowed).</param>
-    /// <param name="description">Parameter description</param>
-    /// <param name="defaultValue">Default parameter value, if not provided</param>
-    /// <param name="type">Parameter type.</param>
-    public ParameterView(
-        string name,
-        string? description = null,
-        string? defaultValue = null,
-        ParameterViewType? type = null)
-    {
-        this.Name = name;
-        this.Description = description;
-        this.DefaultValue = defaultValue;
-        this.Type = type;
-    }
-
-    [DebuggerBrowsable(DebuggerBrowsableState.Never)]
-    private string DebuggerDisplay => string.IsNullOrEmpty(this.Description)
-        ? this.Name
-        : $"{this.Name} ({this.Description})";
-}
+/// <param name="Name">Parameter name. The name must be alphanumeric (underscore is the only special char allowed).</param>
+/// <param name="Description">Parameter description</param>
+/// <param name="DefaultValue">Default parameter value, if not provided</param>
+/// <param name="Type">Parameter type.</param>
+public sealed record ParameterView(
+    string Name,
+    string? Description = null,
+    string? DefaultValue = null,
+    ParameterViewType? Type = null);