Added queryable chunking

Author: jamesmcroft

src/MADE.Collections/QueryableExtensions.cs

@@ -0,0 +1,40 @@
+// MADE Apps licenses this file to you under the MIT license.
+// See the LICENSE file in the project root for more information.
+
+namespace MADE.Collections
+{
+    using System.Collections.Generic;
+    using System.Linq;
+
+    /// <summary>
+    /// Defines a collection of extensions for queryable objects.
+    /// </summary>
+    public static class QueryableExtensions
+    {
+        /// <summary>
+        /// Chunks a query of items into the specified chunk size.
+        /// </summary>
+        /// <typeparam name="T">The type of item.</typeparam>
+        /// <param name="source">The source query to chunk.</param>
+        /// <param name="chunkSize">The chunk size.</param>
+        /// <returns>A collection of queries containing the chunked items.</returns>
+        public static IEnumerable<IQueryable<T>> Chunk<T>(this IQueryable<T> source, int chunkSize = 25)
+        {
+            int idx = 0;
+            while (true)
+            {
+                IQueryable<T> q = idx == 0
+                    ? source
+                    : source.Skip(idx * chunkSize);
+                IQueryable<T> chunk = q.Take(chunkSize);
+                if (!chunk.Any())
+                {
+                    yield break;
+                }
+
+                yield return chunk.AsQueryable();
+                idx++;
+            }
+        }
+    }
+}