Merge branch 'morelinq:master' into scanby

morelinq · Nov 19, 2022 · 48f3387 · 48f3387
2 parents 8520a34 + b31c7fd
commit 48f3387
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Showing 14 changed files with 112 additions and 46 deletions.
diff --git a/MoreLinq.Test/FallbackIfEmptyTest.cs b/MoreLinq.Test/FallbackIfEmptyTest.cs
@@ -60,5 +60,13 @@ public void FallbackIfEmptyPreservesFallbackCollectionIfPossible(SourceKind sour
             Assert.AreSame(source.FallbackIfEmpty(fallback), fallback);
             Assert.AreSame(source.FallbackIfEmpty(fallback.AsEnumerable()), fallback);
         }
+
+        [Test]
+        public void FallbackIfEmptyWithEmptyNullableSequence()
+        {
+            var source = Enumerable.Empty<int?>().Select(x => x);
+            var fallback = (int?)null;
+            source.FallbackIfEmpty(fallback).AssertSequenceEqual(fallback);
+        }
     }
 }
diff --git a/MoreLinq.Test/PartialSortByTest.cs b/MoreLinq.Test/PartialSortByTest.cs
@@ -15,6 +15,8 @@
 // limitations under the License.
 #endregion
 
+#nullable enable
+
 namespace MoreLinq.Test
 {
     using System;

diff --git a/MoreLinq.Test/PartialSortTest.cs b/MoreLinq.Test/PartialSortTest.cs
@@ -15,6 +15,8 @@
 // limitations under the License.
 #endregion
 
+#nullable enable
+
 namespace MoreLinq.Test
 {
     using System;

diff --git a/MoreLinq/Assume.cs b/MoreLinq/Assume.cs
@@ -0,0 +1,31 @@
+#region License and Terms
+// MoreLINQ - Extensions to LINQ to Objects
+// Copyright (c) 2022 Atif Aziz. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#endregion
+
+namespace MoreLinq
+{
+    using System.Runtime.CompilerServices;
+
+    static class Assume
+    {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T NotNull<T>(T? obj) where T : class
+        {
+            Debug.Assert(obj is not null);
+            return obj;
+        }
+    }
+}
diff --git a/MoreLinq/Debug.cs b/MoreLinq/Debug.cs
@@ -0,0 +1,31 @@
+#region License and Terms
+// MoreLINQ - Extensions to LINQ to Objects
+// Copyright (c) 2022 Atif Aziz. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+#endregion
+
+namespace MoreLinq
+{
+    using System.Diagnostics;
+    using System.Diagnostics.CodeAnalysis;
+    using System.Runtime.CompilerServices;
+
+    static class Debug
+    {
+        [Conditional("DEBUG")]
+        public static void Assert([DoesNotReturnIf(false)] bool condition,
+                                  [CallerArgumentExpression(nameof(condition))] string? message = null) =>
+            System.Diagnostics.Debug.Assert(condition);
+    }
+}
diff --git a/MoreLinq/Experimental/Await.cs b/MoreLinq/Experimental/Await.cs
@@ -23,7 +23,6 @@ namespace MoreLinq.Experimental
     using System.Collections;
     using System.Collections.Concurrent;
     using System.Collections.Generic;
-    using System.Diagnostics;
     using System.Linq;
     using System.Runtime.ExceptionServices;
     using System.Threading;
@@ -528,18 +527,15 @@ void PostNotice(Notice notice,
                         catch (OperationCanceledException e) when (e.CancellationToken == consumerCancellationTokenSource.Token)
                         {
                             var (error1, error2) = lastCriticalErrors;
-                            Debug.Assert(error1 is not null);
                             throw new Exception("One or more critical errors have occurred.",
-                                error2 != null ? new AggregateException(error1, error2)
-                                               : new AggregateException(error1));
+                                error2 != null ? new AggregateException(Assume.NotNull(error1), error2)
+                                               : new AggregateException(Assume.NotNull(error1)));
                         }
 
                         var (kind, result, error) = notice.Current;
 
                         if (kind == Notice.Error)
-                        {
-                            error!.Throw();
-                        }
+                            Assume.NotNull(error).Throw();
 
                         if (kind == Notice.End)
                             break;

diff --git a/MoreLinq/Experimental/Memoize.cs b/MoreLinq/Experimental/Memoize.cs
@@ -115,9 +115,7 @@ public IEnumerator<T> GetEnumerator()
                         if (index >= _cache.Count)
                         {
                             if (index == _errorIndex)
-                            {
-                                _error!.Throw();
-                            }
+                                Assume.NotNull(_error).Throw();
 
                             if (_sourceEnumerator == null)
                                 break;

diff --git a/MoreLinq/FallbackIfEmpty.cs b/MoreLinq/FallbackIfEmpty.cs
@@ -19,7 +19,6 @@ namespace MoreLinq
 {
     using System;
     using System.Collections.Generic;
-    using System.Diagnostics;
 
     static partial class MoreEnumerable
     {

diff --git a/MoreLinq/Fold.cs b/MoreLinq/Fold.cs
@@ -69,22 +69,22 @@ static TResult FoldImpl<T, TResult>(IEnumerable<T> source, int count,
 
             return count switch
             {
-                 1 => folder1 !(elements[0]),
-                 2 => folder2 !(elements[0], elements[1]),
-                 3 => folder3 !(elements[0], elements[1], elements[2]),
-                 4 => folder4 !(elements[0], elements[1], elements[2], elements[3]),
-                 5 => folder5 !(elements[0], elements[1], elements[2], elements[3], elements[4]),
-                 6 => folder6 !(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5]),
-                 7 => folder7 !(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6]),
-                 8 => folder8 !(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7]),
-                 9 => folder9 !(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8]),
-                10 => folder10!(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9]),
-                11 => folder11!(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10]),
-                12 => folder12!(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11]),
-                13 => folder13!(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12]),
-                14 => folder14!(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12], elements[13]),
-                15 => folder15!(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12], elements[13], elements[14]),
-                16 => folder16!(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12], elements[13], elements[14], elements[15]),
+                 1 => Assume.NotNull(folder1 )(elements[0]),
+                 2 => Assume.NotNull(folder2 )(elements[0], elements[1]),
+                 3 => Assume.NotNull(folder3 )(elements[0], elements[1], elements[2]),
+                 4 => Assume.NotNull(folder4 )(elements[0], elements[1], elements[2], elements[3]),
+                 5 => Assume.NotNull(folder5 )(elements[0], elements[1], elements[2], elements[3], elements[4]),
+                 6 => Assume.NotNull(folder6 )(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5]),
+                 7 => Assume.NotNull(folder7 )(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6]),
+                 8 => Assume.NotNull(folder8 )(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7]),
+                 9 => Assume.NotNull(folder9 )(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8]),
+                10 => Assume.NotNull(folder10)(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9]),
+                11 => Assume.NotNull(folder11)(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10]),
+                12 => Assume.NotNull(folder12)(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11]),
+                13 => Assume.NotNull(folder13)(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12]),
+                14 => Assume.NotNull(folder14)(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12], elements[13]),
+                15 => Assume.NotNull(folder15)(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12], elements[13], elements[14]),
+                16 => Assume.NotNull(folder16)(elements[0], elements[1], elements[2], elements[3], elements[4], elements[5], elements[6], elements[7], elements[8], elements[9], elements[10], elements[11], elements[12], elements[13], elements[14], elements[15]),
                 _ => throw new NotSupportedException()
             };
         }

diff --git a/MoreLinq/Lookup.cs b/MoreLinq/Lookup.cs
@@ -24,12 +24,6 @@
 // SOFTWARE.
 #endregion
 
-#if !NET6_0_OR_GREATER
-#nullable enable annotations
-#pragma warning disable 8602 // Dereference of a possibly null reference.
-#pragma warning disable 8603 // Possible null reference return.
-#endif
-
 namespace MoreLinq
 {
     using System;
@@ -65,7 +59,10 @@ internal static Lookup<TKey, TElement> Create<TSource>(IEnumerable<TSource> sour
             var lookup = new Lookup<TKey, TElement>(comparer);
 
             foreach (var item in source)
-                lookup.GetGrouping(keySelector(item), create: true)!.Add(elementSelector(item));
+            {
+                var grouping = Assume.NotNull(lookup.GetGrouping(keySelector(item), create: true));
+                grouping.Add(elementSelector(item));
+            }
 
             return lookup;
         }
@@ -78,7 +75,10 @@ internal static Lookup<TKey, TElement> Create(IEnumerable<TElement> source, Func
             var lookup = new Lookup<TKey, TElement>(comparer);
 
             foreach (var item in source)
-                lookup.GetGrouping(keySelector(item), create: true)!.Add(item);
+            {
+                var grouping = Assume.NotNull(lookup.GetGrouping(keySelector(item), create: true));
+                grouping.Add(item);
+            }
 
             return lookup;
         }
@@ -90,7 +90,10 @@ internal static Lookup<TKey, TElement> CreateForJoin(IEnumerable<TElement> sourc
             foreach (var item in source)
             {
                 if (keySelector(item) is { } key)
-                    lookup.GetGrouping(key, create: true)!.Add(item);
+                {
+                    var grouping = Assume.NotNull(lookup.GetGrouping(key, create: true));
+                    grouping.Add(item);
+                }
             }
 
             return lookup;
@@ -122,9 +125,7 @@ public IEnumerator<IGrouping<TKey, TElement>> GetEnumerator()
             {
                 do
                 {
-                    g = g._next;
-
-                    Debug.Assert(g is not null);
+                    g = Assume.NotNull(g._next);
                     yield return g;
                 }
                 while (g != _lastGrouping);
@@ -179,10 +180,10 @@ void Resize()
         {
             var newSize = checked((_count * 2) + 1);
             var newGroupings = new Grouping<TKey, TElement>[newSize];
-            var g = _lastGrouping!;
+            var g = Assume.NotNull(_lastGrouping);
             do
             {
-                g = g._next!;
+                g = Assume.NotNull(g._next);
                 var index = g._hashCode % newSize;
                 g._hashNext = newGroupings[index];
                 newGroupings[index] = g;

diff --git a/MoreLinq/Pad.cs b/MoreLinq/Pad.cs
@@ -19,7 +19,6 @@ namespace MoreLinq
 {
     using System;
     using System.Collections.Generic;
-    using System.Diagnostics;
 
     static partial class MoreEnumerable
     {

diff --git a/MoreLinq/PartialSort.cs b/MoreLinq/PartialSort.cs
@@ -242,7 +242,7 @@ static IEnumerable<TSource> PartialSortByImpl<TSource, TKey>(
             {
                 if (keys != null)
                 {
-                    var key = keySelector!(item);
+                    var key = Assume.NotNull(keySelector)(item);
                     if (Insert(keys, key, keyComparer) is {} i)
                     {
                         if (top.Count == count)

diff --git a/MoreLinq/Partition.cs b/MoreLinq/Partition.cs
@@ -19,7 +19,6 @@ namespace MoreLinq
 {
     using System;
     using System.Collections.Generic;
-    using System.Diagnostics;
     using System.Linq;
 
     static partial class MoreEnumerable

diff --git a/MoreLinq/Reactive/Subject.cs b/MoreLinq/Reactive/Subject.cs
@@ -116,12 +116,12 @@ public void OnNext(T value)
         }
 
         public void OnError(Exception error) =>
-            OnFinality(ref _error, error, (observer, err) => observer.OnError(err!));
+            OnFinality(ref _error, error, (observer, err) => observer.OnError(err));
 
         public void OnCompleted() =>
             OnFinality(ref _completed, true, (observer, _) => observer.OnCompleted());
 
-        void OnFinality<TState>(ref TState state, TState value, Action<IObserver<T>, TState> action)
+        void OnFinality<TState>(ref TState? state, TState value, Action<IObserver<T>, TState> action)
         {
             if (IsMuted)
                 return;