support for collection shuffle

src/Microsoft.DotNet.Interactive.AIUtilities.Tests/SamplingTest.cs

@@ -0,0 +1,26 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+using FluentAssertions;
+using Xunit;
+
+namespace Microsoft.DotNet.Interactive.AIUtilities.Tests;
+
+public class SamplingTest
+{
+    [Fact]
+    public void can_shuffle_collection()
+    {
+        var src = Enumerable.Range(0, 10);
+        var shuffled = src.Shuffle().ToArray();
+        shuffled.Should().NotBeInAscendingOrder();
+    }
+
+    [Fact]
+    public void does_not_duplicate_items()
+    {
+        var src = Enumerable.Range(0, 10).ToArray();
+        var shuffled = src.Shuffle().Distinct().ToArray();
+        shuffled.Should().HaveCount(src.Length);
+    }
+}

src/Microsoft.DotNet.Interactive.AIUtilities/Sampling.cs

@@ -0,0 +1,21 @@
+// Copyright (c) .NET Foundation and contributors. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+
+namespace Microsoft.DotNet.Interactive.AIUtilities;
+
+public static class Sampling
+{
+    public static IEnumerable<T> Shuffle<T>(this IEnumerable<T> source)
+    {
+        var rnd = new Random();
+        var list = new List<T>(source);
+        while (list.Count > 0)
+        {
+            var pos = rnd.Next(list.Count);
+            var sample = list.ElementAt(pos);
+            list.RemoveAt(pos);
+            yield return sample;
+
+        }
+    }
+}