Adding Generate.

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

@@ -0,0 +1,535 @@
+// 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.Reactive.Concurrency;
+using System.Threading.Tasks;
+
+namespace System.Reactive.Linq
+{
+    partial class AsyncObservable
+    {
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, IAsyncScheduler scheduler)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, scheduler));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, IAsyncScheduler scheduler)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, scheduler));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, TimeSpan> timeSelector)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, TimeSpan> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector, scheduler));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<TimeSpan>> timeSelector)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<TimeSpan>> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector, scheduler));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, DateTimeOffset> timeSelector)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, DateTimeOffset> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector, scheduler));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<DateTimeOffset>> timeSelector)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector));
+        }
+
+        public static IAsyncObservable<TResult> Generate<TState, TResult>(TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<DateTimeOffset>> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Create<TResult>(observer => AsyncObserver.Generate(observer, initialState, condition, iterate, resultSelector, timeSelector, scheduler));
+        }
+    }
+
+    partial class AsyncObserver
+    {
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+
+            return Generate(observer, initialState, s => Task.FromResult(condition(s)), s => Task.FromResult(iterate(s)), s => Task.FromResult(resultSelector(s)), TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Generate(observer, initialState, s => Task.FromResult(condition(s)), s => Task.FromResult(iterate(s)), s => Task.FromResult(resultSelector(s)), scheduler);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+
+            return Generate(observer, initialState, condition, iterate, resultSelector, TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return scheduler.ScheduleAsync(async ct =>
+            {
+                var first = true;
+                var state = initialState;
+
+                while (!ct.IsCancellationRequested)
+                {
+                    var hasResult = false;
+                    var result = default(TResult);
+
+                    try
+                    {
+                        if (first)
+                        {
+                            first = false;
+                        }
+                        else
+                        {
+                            state = await iterate(state).RendezVous(scheduler);
+                        }
+
+                        hasResult = await condition(state).RendezVous(scheduler);
+
+                        if (hasResult)
+                        {
+                            result = await resultSelector(state).RendezVous(scheduler);
+                        }
+                    }
+                    catch (Exception ex)
+                    {
+                        await observer.OnErrorAsync(ex).RendezVous(scheduler);
+                        return;
+                    }
+
+                    if (hasResult)
+                    {
+                        await observer.OnNextAsync(result).RendezVous(scheduler);
+                    }
+                    else
+                    {
+                        break;
+                    }
+                }
+
+                if (!ct.IsCancellationRequested)
+                {
+                    await observer.OnCompletedAsync().RendezVous(scheduler);
+                }
+            });
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, TimeSpan> timeSelector)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Generate(observer, initialState, s => Task.FromResult(condition(s)), s => Task.FromResult(iterate(s)), s => Task.FromResult(resultSelector(s)), s => Task.FromResult(timeSelector(s)), TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, TimeSpan> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Generate(observer, initialState, s => Task.FromResult(condition(s)), s => Task.FromResult(iterate(s)), s => Task.FromResult(resultSelector(s)), s => Task.FromResult(timeSelector(s)), scheduler);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<TimeSpan>> timeSelector)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Generate(observer, initialState, condition, iterate, resultSelector, timeSelector, TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<TimeSpan>> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return scheduler.ScheduleAsync(async ct =>
+            {
+                var first = true;
+                var state = initialState;
+
+                while (!ct.IsCancellationRequested)
+                {
+                    var hasResult = false;
+                    var result = default(TResult);
+                    var nextDue = default(TimeSpan);
+
+                    try
+                    {
+                        if (first)
+                        {
+                            first = false;
+                        }
+                        else
+                        {
+                            state = await iterate(state).RendezVous(scheduler);
+                        }
+
+                        hasResult = await condition(state).RendezVous(scheduler);
+
+                        if (hasResult)
+                        {
+                            result = await resultSelector(state).RendezVous(scheduler);
+                            nextDue = await timeSelector(state).RendezVous(scheduler);
+                        }
+                    }
+                    catch (Exception ex)
+                    {
+                        await observer.OnErrorAsync(ex).RendezVous(scheduler);
+                        return;
+                    }
+
+                    if (hasResult)
+                    {
+                        await observer.OnNextAsync(result).RendezVous(scheduler);
+                    }
+                    else
+                    {
+                        break;
+                    }
+
+                    await scheduler.Delay(nextDue).RendezVous(scheduler);
+                }
+
+                if (!ct.IsCancellationRequested)
+                {
+                    await observer.OnCompletedAsync().RendezVous(scheduler);
+                }
+            });
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, DateTimeOffset> timeSelector)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Generate(observer, initialState, s => Task.FromResult(condition(s)), s => Task.FromResult(iterate(s)), s => Task.FromResult(resultSelector(s)), s => Task.FromResult(timeSelector(s)), TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, bool> condition, Func<TState, TState> iterate, Func<TState, TResult> resultSelector, Func<TState, DateTimeOffset> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return Generate(observer, initialState, s => Task.FromResult(condition(s)), s => Task.FromResult(iterate(s)), s => Task.FromResult(resultSelector(s)), s => Task.FromResult(timeSelector(s)), scheduler);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<DateTimeOffset>> timeSelector)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+
+            return Generate(observer, initialState, condition, iterate, resultSelector, timeSelector, TaskPoolAsyncScheduler.Default);
+        }
+
+        public static Task<IAsyncDisposable> Generate<TState, TResult>(IAsyncObserver<TResult> observer, TState initialState, Func<TState, Task<bool>> condition, Func<TState, Task<TState>> iterate, Func<TState, Task<TResult>> resultSelector, Func<TState, Task<DateTimeOffset>> timeSelector, IAsyncScheduler scheduler)
+        {
+            if (observer == null)
+                throw new ArgumentNullException(nameof(observer));
+            if (condition == null)
+                throw new ArgumentNullException(nameof(condition));
+            if (iterate == null)
+                throw new ArgumentNullException(nameof(iterate));
+            if (resultSelector == null)
+                throw new ArgumentNullException(nameof(resultSelector));
+            if (timeSelector == null)
+                throw new ArgumentNullException(nameof(timeSelector));
+            if (scheduler == null)
+                throw new ArgumentNullException(nameof(scheduler));
+
+            return scheduler.ScheduleAsync(async ct =>
+            {
+                var first = true;
+                var state = initialState;
+
+                while (!ct.IsCancellationRequested)
+                {
+                    var hasResult = false;
+                    var result = default(TResult);
+                    var nextDue = default(DateTimeOffset);
+
+                    try
+                    {
+                        if (first)
+                        {
+                            first = false;
+                        }
+                        else
+                        {
+                            state = await iterate(state).RendezVous(scheduler);
+                        }
+
+                        hasResult = await condition(state).RendezVous(scheduler);
+
+                        if (hasResult)
+                        {
+                            result = await resultSelector(state).RendezVous(scheduler);
+                            nextDue = await timeSelector(state).RendezVous(scheduler);
+                        }
+                    }
+                    catch (Exception ex)
+                    {
+                        await observer.OnErrorAsync(ex).RendezVous(scheduler);
+                        return;
+                    }
+
+                    if (hasResult)
+                    {
+                        await observer.OnNextAsync(result).RendezVous(scheduler);
+                    }
+                    else
+                    {
+                        break;
+                    }
+
+                    await scheduler.Delay(nextDue).RendezVous(scheduler);
+                }
+
+                if (!ct.IsCancellationRequested)
+                {
+                    await observer.OnCompletedAsync().RendezVous(scheduler);
+                }
+            });
+        }
+    }
+}