Refactor Where/Select optimizations

Ix.NET/Source/System.Linq.Async/System/Linq/Operators/Select.Opt.cs

@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information. 
+
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace System.Linq
+{
+    public static partial class AsyncEnumerable
+    {
+        private static Func<TSource, TResult> CombineSelectors<TSource, TMiddle, TResult>(Func<TSource, TMiddle> selector1, Func<TMiddle, TResult> selector2)
+        {
+            return x => selector2(selector1(x));
+        }
+
+        private static Func<TSource, ValueTask<TResult>> CombineSelectors<TSource, TMiddle, TResult>(Func<TSource, ValueTask<TMiddle>> selector1, Func<TMiddle, ValueTask<TResult>> selector2)
+        {
+            return async x => await selector2(await selector1(x).ConfigureAwait(false)).ConfigureAwait(false);
+        }
+
+#if !NO_DEEP_CANCELLATION
+        private static Func<TSource, CancellationToken, ValueTask<TResult>> CombineSelectors<TSource, TMiddle, TResult>(Func<TSource, CancellationToken, ValueTask<TMiddle>> selector1, Func<TMiddle, CancellationToken, ValueTask<TResult>> selector2)
+        {
+            return async (x, ct) => await selector2(await selector1(x, ct).ConfigureAwait(false), ct).ConfigureAwait(false);
+        }
+#endif
+    }
+}

Ix.NET/Source/System.Linq.Async/System/Linq/Operators/Select.cs

@@ -99,23 +99,6 @@ namespace System.Linq
         }
 #endif
 
-        private static Func<TSource, TResult> CombineSelectors<TSource, TMiddle, TResult>(Func<TSource, TMiddle> selector1, Func<TMiddle, TResult> selector2)
-        {
-            return x => selector2(selector1(x));
-        }
-
-        private static Func<TSource, ValueTask<TResult>> CombineSelectors<TSource, TMiddle, TResult>(Func<TSource, ValueTask<TMiddle>> selector1, Func<TMiddle, ValueTask<TResult>> selector2)
-        {
-            return async x => await selector2(await selector1(x).ConfigureAwait(false)).ConfigureAwait(false);
-        }
-
-#if !NO_DEEP_CANCELLATION
-        private static Func<TSource, CancellationToken, ValueTask<TResult>> CombineSelectors<TSource, TMiddle, TResult>(Func<TSource, CancellationToken, ValueTask<TMiddle>> selector1, Func<TMiddle, CancellationToken, ValueTask<TResult>> selector2)
-        {
-            return async (x, ct) => await selector2(await selector1(x, ct).ConfigureAwait(false), ct).ConfigureAwait(false);
-        }
-#endif
-
         internal sealed class SelectEnumerableAsyncIterator<TSource, TResult> : AsyncIterator<TResult>
         {
             private readonly Func<TSource, TResult> _selector;

Ix.NET/Source/System.Linq.Async/System/Linq/Operators/Where.Opt.cs

@@ -0,0 +1,31 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the Apache 2.0 License.
+// See the LICENSE file in the project root for more information. 
+
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace System.Linq
+{
+    public static partial class AsyncEnumerable
+    {
+        private static Func<TSource, bool> CombinePredicates<TSource>(Func<TSource, bool> predicate1, Func<TSource, bool> predicate2)
+        {
+            return x => predicate1(x) && predicate2(x);
+        }
+
+        private static Func<TSource, ValueTask<bool>> CombinePredicates<TSource>(Func<TSource, ValueTask<bool>> predicate1, Func<TSource, ValueTask<bool>> predicate2)
+        {
+            return async x => await predicate1(x).ConfigureAwait(false) && await predicate2(x).ConfigureAwait(false);
+        }
+
+#if !NO_DEEP_CANCELLATION
+        private static Func<TSource, CancellationToken, ValueTask<bool>> CombinePredicates<TSource>(Func<TSource, CancellationToken, ValueTask<bool>> predicate1, Func<TSource, CancellationToken, ValueTask<bool>> predicate2)
+        {
+            return async (x, ct) => await predicate1(x, ct).ConfigureAwait(false) && await predicate2(x, ct).ConfigureAwait(false);
+        }
+#endif
+    }
+}

Ix.NET/Source/System.Linq.Async/System/Linq/Operators/Where.cs

@@ -93,23 +93,6 @@ namespace System.Linq
         }
 #endif
 
-        private static Func<TSource, bool> CombinePredicates<TSource>(Func<TSource, bool> predicate1, Func<TSource, bool> predicate2)
-        {
-            return x => predicate1(x) && predicate2(x);
-        }
-
-        private static Func<TSource, ValueTask<bool>> CombinePredicates<TSource>(Func<TSource, ValueTask<bool>> predicate1, Func<TSource, ValueTask<bool>> predicate2)
-        {
-            return async x => await predicate1(x).ConfigureAwait(false) && await predicate2(x).ConfigureAwait(false);
-        }
-
-#if !NO_DEEP_CANCELLATION
-        private static Func<TSource, CancellationToken, ValueTask<bool>> CombinePredicates<TSource>(Func<TSource, CancellationToken, ValueTask<bool>> predicate1, Func<TSource, CancellationToken, ValueTask<bool>> predicate2)
-        {
-            return async (x, ct) => await predicate1(x, ct).ConfigureAwait(false) && await predicate2(x, ct).ConfigureAwait(false);
-        }
-#endif
-
         internal sealed class WhereEnumerableAsyncIterator<TSource> : AsyncIterator<TSource>
         {
             private readonly Func<TSource, bool> _predicate;