Changing a few classes to private.

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

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information. 
 
 using System.Collections.Generic;
-using System.Diagnostics;
 using System.Threading.Tasks;
 
 namespace System.Linq
@@ -15,7 +14,6 @@ namespace System.Linq
             if (source == null)
                 throw Error.ArgumentNull(nameof(source));
 
-            // Check to see if it already is and short-circuit
             if (source is IAsyncEnumerable<TResult> typedSource)
             {
                 return typedSource;
@@ -24,15 +22,13 @@ namespace System.Linq
             return new CastAsyncIterator<TResult>(source);
         }
 
-        internal sealed class CastAsyncIterator<TResult> : AsyncIterator<TResult>
+        private sealed class CastAsyncIterator<TResult> : AsyncIterator<TResult>
         {
             private readonly IAsyncEnumerable<object> _source;
             private IAsyncEnumerator<object> _enumerator;
 
             public CastAsyncIterator(IAsyncEnumerable<object> source)
             {
-                Debug.Assert(source != null);
-
                 _source = source;
             }
 

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

@@ -315,7 +315,7 @@ namespace System.Linq
         }
 #endif
 
-        internal sealed class GroupedResultAsyncEnumerable<TSource, TKey, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
+        private sealed class GroupedResultAsyncEnumerable<TSource, TKey, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, TKey> _keySelector;
@@ -408,7 +408,7 @@ namespace System.Linq
             }
         }
 
-        internal sealed class GroupedResultAsyncEnumerableWithTask<TSource, TKey, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
+        private sealed class GroupedResultAsyncEnumerableWithTask<TSource, TKey, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, ValueTask<TKey>> _keySelector;
@@ -502,7 +502,7 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal sealed class GroupedResultAsyncEnumerableWithTaskAndCancellation<TSource, TKey, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
+        private sealed class GroupedResultAsyncEnumerableWithTaskAndCancellation<TSource, TKey, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, CancellationToken, ValueTask<TKey>> _keySelector;
@@ -596,7 +596,7 @@ namespace System.Linq
         }
 #endif
 
-        internal sealed class GroupedAsyncEnumerable<TSource, TKey, TElement> : AsyncIterator<IAsyncGrouping<TKey, TElement>>, IAsyncIListProvider<IAsyncGrouping<TKey, TElement>>
+        private sealed class GroupedAsyncEnumerable<TSource, TKey, TElement> : AsyncIterator<IAsyncGrouping<TKey, TElement>>, IAsyncIListProvider<IAsyncGrouping<TKey, TElement>>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, TKey> _keySelector;
@@ -689,7 +689,7 @@ namespace System.Linq
             }
         }
 
-        internal sealed class GroupedAsyncEnumerableWithTask<TSource, TKey, TElement> : AsyncIterator<IAsyncGrouping<TKey, TElement>>, IAsyncIListProvider<IAsyncGrouping<TKey, TElement>>
+        private sealed class GroupedAsyncEnumerableWithTask<TSource, TKey, TElement> : AsyncIterator<IAsyncGrouping<TKey, TElement>>, IAsyncIListProvider<IAsyncGrouping<TKey, TElement>>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, ValueTask<TKey>> _keySelector;
@@ -783,7 +783,7 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal sealed class GroupedAsyncEnumerableWithTaskAndCancellation<TSource, TKey, TElement> : AsyncIterator<IAsyncGrouping<TKey, TElement>>, IAsyncIListProvider<IAsyncGrouping<TKey, TElement>>
+        private sealed class GroupedAsyncEnumerableWithTaskAndCancellation<TSource, TKey, TElement> : AsyncIterator<IAsyncGrouping<TKey, TElement>>, IAsyncIListProvider<IAsyncGrouping<TKey, TElement>>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, CancellationToken, ValueTask<TKey>> _keySelector;
@@ -877,7 +877,7 @@ namespace System.Linq
         }
 #endif
 
-        internal sealed class GroupedAsyncEnumerable<TSource, TKey> : AsyncIterator<IAsyncGrouping<TKey, TSource>>, IAsyncIListProvider<IAsyncGrouping<TKey, TSource>>
+        private sealed class GroupedAsyncEnumerable<TSource, TKey> : AsyncIterator<IAsyncGrouping<TKey, TSource>>, IAsyncIListProvider<IAsyncGrouping<TKey, TSource>>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, TKey> _keySelector;
@@ -967,7 +967,7 @@ namespace System.Linq
             }
         }
 
-        internal sealed class GroupedAsyncEnumerableWithTask<TSource, TKey> : AsyncIterator<IAsyncGrouping<TKey, TSource>>, IAsyncIListProvider<IAsyncGrouping<TKey, TSource>>
+        private sealed class GroupedAsyncEnumerableWithTask<TSource, TKey> : AsyncIterator<IAsyncGrouping<TKey, TSource>>, IAsyncIListProvider<IAsyncGrouping<TKey, TSource>>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, ValueTask<TKey>> _keySelector;
@@ -1058,7 +1058,7 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal sealed class GroupedAsyncEnumerableWithTaskAndCancellation<TSource, TKey> : AsyncIterator<IAsyncGrouping<TKey, TSource>>, IAsyncIListProvider<IAsyncGrouping<TKey, TSource>>
+        private sealed class GroupedAsyncEnumerableWithTaskAndCancellation<TSource, TKey> : AsyncIterator<IAsyncGrouping<TKey, TSource>>, IAsyncIListProvider<IAsyncGrouping<TKey, TSource>>
         {
             private readonly IAsyncEnumerable<TSource> _source;
             private readonly Func<TSource, CancellationToken, ValueTask<TKey>> _keySelector;

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

@@ -111,7 +111,7 @@ namespace System.Linq
         }
 #endif
 
-        internal sealed class JoinAsyncIterator<TOuter, TInner, TKey, TResult> : AsyncIterator<TResult>
+        private sealed class JoinAsyncIterator<TOuter, TInner, TKey, TResult> : AsyncIterator<TResult>
         {
             private readonly IAsyncEnumerable<TOuter> _outer;
             private readonly IAsyncEnumerable<TInner> _inner;
@@ -238,7 +238,7 @@ namespace System.Linq
             }
         }
 
-        internal sealed class JoinAsyncIteratorWithTask<TOuter, TInner, TKey, TResult> : AsyncIterator<TResult>
+        private sealed class JoinAsyncIteratorWithTask<TOuter, TInner, TKey, TResult> : AsyncIterator<TResult>
         {
             private readonly IAsyncEnumerable<TOuter> _outer;
             private readonly IAsyncEnumerable<TInner> _inner;
@@ -366,7 +366,7 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal sealed class JoinAsyncIteratorWithTaskAndCancellation<TOuter, TInner, TKey, TResult> : AsyncIterator<TResult>
+        private sealed class JoinAsyncIteratorWithTaskAndCancellation<TOuter, TInner, TKey, TResult> : AsyncIterator<TResult>
         {
             private readonly IAsyncEnumerable<TOuter> _outer;
             private readonly IAsyncEnumerable<TInner> _inner;

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

@@ -3,8 +3,6 @@
 // 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
@@ -19,15 +17,13 @@ namespace System.Linq
             return new OfTypeAsyncIterator<TResult>(source);
         }
 
-        internal sealed class OfTypeAsyncIterator<TResult> : AsyncIterator<TResult>
+        private sealed class OfTypeAsyncIterator<TResult> : AsyncIterator<TResult>
         {
             private readonly IAsyncEnumerable<object> _source;
             private IAsyncEnumerator<object> _enumerator;
 
             public OfTypeAsyncIterator(IAsyncEnumerable<object> source)
             {
-                Debug.Assert(source != null);
-
                 _source = source;
             }
 

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

@@ -177,7 +177,7 @@ namespace System.Linq
             }
         }
 
-        internal sealed class SelectEnumerableWithIndexAsyncIterator<TSource, TResult> : AsyncIterator<TResult>
+        private sealed class SelectEnumerableWithIndexAsyncIterator<TSource, TResult> : AsyncIterator<TResult>
         {
             private readonly Func<TSource, int, TResult> _selector;
             private readonly IAsyncEnumerable<TSource> _source;
@@ -481,7 +481,7 @@ namespace System.Linq
         }
 #endif
 
-        internal sealed class SelectEnumerableWithIndexAsyncIteratorWithTask<TSource, TResult> : AsyncIterator<TResult>
+        private sealed class SelectEnumerableWithIndexAsyncIteratorWithTask<TSource, TResult> : AsyncIterator<TResult>
         {
             private readonly Func<TSource, int, ValueTask<TResult>> _selector;
             private readonly IAsyncEnumerable<TSource> _source;
@@ -546,7 +546,7 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal sealed class SelectEnumerableWithIndexAsyncIteratorWithTaskAndCancellation<TSource, TResult> : AsyncIterator<TResult>
+        private sealed class SelectEnumerableWithIndexAsyncIteratorWithTaskAndCancellation<TSource, TResult> : AsyncIterator<TResult>
         {
             private readonly Func<TSource, int, CancellationToken, ValueTask<TResult>> _selector;
             private readonly IAsyncEnumerable<TSource> _source;
@@ -616,7 +616,7 @@ namespace System.Linq
         //     elements in order to ensure side-effects. We should consider whether we want to follow this implementation
         //     strategy or support IAsyncPartition<TResult> in a less efficient but more correct manner here.
 
-        internal sealed class SelectIListIteratorWithTask<TSource, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
+        private sealed class SelectIListIteratorWithTask<TSource, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
         {
             private readonly Func<TSource, ValueTask<TResult>> _selector;
             private readonly IList<TSource> _source;
@@ -738,7 +738,7 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal sealed class SelectIListIteratorWithTaskAndCancellation<TSource, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
+        private sealed class SelectIListIteratorWithTaskAndCancellation<TSource, TResult> : AsyncIterator<TResult>, IAsyncIListProvider<TResult>
         {
             private readonly Func<TSource, CancellationToken, ValueTask<TResult>> _selector;
             private readonly IList<TSource> _source;

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

@@ -179,7 +179,7 @@ namespace System.Linq
             }
         }
 
-        internal sealed class WhereEnumerableWithIndexAsyncIterator<TSource> : AsyncIterator<TSource>
+        private sealed class WhereEnumerableWithIndexAsyncIterator<TSource> : AsyncIterator<TSource>
         {
             private readonly Func<TSource, int, bool> _predicate;
             private readonly IAsyncEnumerable<TSource> _source;
@@ -377,7 +377,7 @@ namespace System.Linq
         }
 #endif
 
-        internal sealed class WhereEnumerableWithIndexAsyncIteratorWithTask<TSource> : AsyncIterator<TSource>
+        private sealed class WhereEnumerableWithIndexAsyncIteratorWithTask<TSource> : AsyncIterator<TSource>
         {
             private readonly Func<TSource, int, ValueTask<bool>> _predicate;
             private readonly IAsyncEnumerable<TSource> _source;
@@ -446,7 +446,7 @@ namespace System.Linq
         }
 
 #if !NO_DEEP_CANCELLATION
-        internal sealed class WhereEnumerableWithIndexAsyncIteratorWithTaskAndCancellation<TSource> : AsyncIterator<TSource>
+        private sealed class WhereEnumerableWithIndexAsyncIteratorWithTaskAndCancellation<TSource> : AsyncIterator<TSource>
         {
             private readonly Func<TSource, int, CancellationToken, ValueTask<bool>> _predicate;
             private readonly IAsyncEnumerable<TSource> _source;
@@ -515,7 +515,7 @@ namespace System.Linq
         }
 #endif
 
-        internal sealed class WhereSelectEnumerableAsyncIterator<TSource, TResult> : AsyncIterator<TResult>
+        private sealed class WhereSelectEnumerableAsyncIterator<TSource, TResult> : AsyncIterator<TResult>
         {
             private readonly Func<TSource, bool> _predicate;
             private readonly Func<TSource, TResult> _selector;