Add 'SyntaxKind' extensions

Author: Sergio0694

components/DependencyPropertyGenerator/CommunityToolkit.DependencyPropertyGenerator.SourceGenerators/Extensions/SyntaxKindExtensions.cs

@@ -0,0 +1,39 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+using System.Collections.Immutable;
+using System.Runtime.CompilerServices;
+using Microsoft.CodeAnalysis.CSharp;
+
+namespace CommunityToolkit.GeneratedDependencyProperty.Extensions;
+
+/// <summary>
+/// A <see langword="class"/> with some extension methods for C# syntax kinds.
+/// </summary>
+internal static partial class SyntaxKindExtensions
+{
+    /// <summary>
+    /// Converts an <see cref="ImmutableArray{T}"/> of <see cref="SyntaxKind"/> values to one of their underlying type.
+    /// </summary>
+    /// <param name="array">The input <see cref="ImmutableArray{T}"/> value.</param>
+    /// <returns>The resulting <see cref="ImmutableArray{T}"/> of <see cref="ushort"/> values.</returns>
+    public static ImmutableArray<ushort> AsUnderlyingType(this ImmutableArray<SyntaxKind> array)
+    {
+        ushort[]? underlyingArray = (ushort[]?)(object?)Unsafe.As<ImmutableArray<SyntaxKind>, SyntaxKind[]?>(ref array);
+
+        return Unsafe.As<ushort[]?, ImmutableArray<ushort>>(ref underlyingArray);
+    }
+
+    /// <summary>
+    /// Converts an <see cref="ImmutableArray{T}"/> of <see cref="ushort"/> values to one of their real type.
+    /// </summary>
+    /// <param name="array">The input <see cref="ImmutableArray{T}"/> value.</param>
+    /// <returns>The resulting <see cref="ImmutableArray{T}"/> of <see cref="SyntaxKind"/> values.</returns>
+    public static ImmutableArray<SyntaxKind> AsSyntaxKindArray(this ImmutableArray<ushort> array)
+    {
+        SyntaxKind[]? typedArray = (SyntaxKind[]?)(object?)Unsafe.As<ImmutableArray<ushort>, ushort[]?>(ref array);
+
+        return Unsafe.As<SyntaxKind[]?, ImmutableArray<SyntaxKind>>(ref typedArray);
+    }
+}