Adding Concat.

AsyncRx.NET/System.Reactive.Async.Linq/System/Reactive/Linq/Operators/Repeat.cs

@@ -0,0 +1,176 @@
+// 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.Linq;
+using System.Reactive.Concurrency;
+using System.Reactive.Disposables;
+using System.Threading.Tasks;
+
+namespace System.Reactive.Linq
+{
+    partial class AsyncObservable
+    {
+        public static IAsyncObservable<TSource> Repeat<TSource>(TSource value)
+        {
+            return Create<TSource>(observer => AsyncObserver.Repeat(observer, value));
+        }
+
+        public static IAsyncObservable<TSource> Repeat<TSource>(TSource value, IAsyncScheduler scheduler)
+        {
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TSource>(observer => AsyncObserver.Repeat(observer, value, scheduler));
+        }
+
+        public static IAsyncObservable<TSource> Repeat<TSource>(TSource value, int repeatCount)
+        {
+            if (repeatCount < 0)
+                throw new ArgumentNullException(nameof(repeatCount));
+
+            return Create<TSource>(observer => AsyncObserver.Repeat(observer, value, repeatCount));
+        }
+
+        public static IAsyncObservable<TSource> Repeat<TSource>(TSource value, int repeatCount, IAsyncScheduler scheduler)
+        {
+            if (repeatCount < 0)
+                throw new ArgumentNullException(nameof(repeatCount));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TSource>(observer => AsyncObserver.Repeat(observer, value, repeatCount, scheduler));
+        }
+
+        public static IAsyncObservable<TSource> Repeat<TSource>(this IAsyncObservable<TSource> source)
+        {
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+
+            return Create<TSource>(observer => AsyncObserver.Repeat(observer, source));
+        }
+
+        public static IAsyncObservable<TSource> Repeat<TSource>(this IAsyncObservable<TSource> source, int repeatCount)
+        {
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+            if (repeatCount < 0)
+                throw new ArgumentNullException(nameof(repeatCount));
+
+            return Create<TSource>(observer => AsyncObserver.Repeat(observer, source, repeatCount));
+        }
+    }
+
+    partial class AsyncObserver
+    {
+        public static Task<IAsyncDisposable> Repeat<TSource>(IAsyncObserver<TSource> observer, TSource value)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+
+            return Repeat(observer, value, TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Repeat<TSource>(IAsyncObserver<TSource> observer, TSource value, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return scheduler.ScheduleAsync(async ct =>
+            {
+                while (!ct.IsCancellationRequested)
+                {
+                    await observer.OnNextAsync(value).RendezVous(scheduler);
+                }
+            });
+        }
+
+        public static Task<IAsyncDisposable> Repeat<TSource>(IAsyncObserver<TSource> observer, TSource value, int repeatCount)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (repeatCount < 0)
+                throw new ArgumentNullException(nameof(repeatCount));
+
+            return Repeat(observer, value, repeatCount, TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Repeat<TSource>(IAsyncObserver<TSource> observer, TSource value, int repeatCount, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (repeatCount < 0)
+                throw new ArgumentNullException(nameof(repeatCount));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return scheduler.ScheduleAsync(async ct =>
+            {
+                var i = 0;
+
+                while (!ct.IsCancellationRequested && i < repeatCount)
+                {
+                    await observer.OnNextAsync(value).RendezVous(scheduler);
+
+                    i++;
+                }
+
+                if (i == repeatCount)
+                {
+                    await observer.OnCompletedAsync().RendezVous(scheduler);
+                }
+            });
+        }
+
+        public static Task<IAsyncDisposable> Repeat<TSource>(IAsyncObserver<TSource> observer, IAsyncObservable<TSource> source)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+
+            async Task<IAsyncDisposable> CoreAsync()
+            {
+                var (sink, inner) = Concat(observer, Repeat(source).GetEnumerator());
+
+                var subscription = await source.SubscribeAsync(sink).ConfigureAwait(false);
+
+                return StableCompositeAsyncDisposable.Create(subscription, inner);
+            }
+
+            return CoreAsync();
+        }
+
+        public static Task<IAsyncDisposable> Repeat<TSource>(IAsyncObserver<TSource> observer, IAsyncObservable<TSource> source, int repeatCount)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (source == null)
+                throw new ArgumentNullException(nameof(source));
+            if (repeatCount < 0)
+                throw new ArgumentNullException(nameof(repeatCount));
+
+            async Task<IAsyncDisposable> CoreAsync()
+            {
+                var (sink, inner) = Concat(observer, Enumerable.Repeat(source, repeatCount).GetEnumerator());
+
+                var subscription = await source.SubscribeAsync(sink).ConfigureAwait(false);
+
+                return StableCompositeAsyncDisposable.Create(subscription, inner);
+            }
+
+            return CoreAsync();
+        }
+
+        private static IEnumerable<T> Repeat<T>(T value)
+        {
+            while (true)
+            {
+                yield return value;
+            }
+        }
+    }
+}