Add CombineLatest

src/UniTask.NetCoreSandbox/Program.cs

@@ -93,10 +93,16 @@ namespace NetCoreSandbox
 
             var channel = Channel.CreateSingleConsumerUnbounded<int>();
 
+            // Observable.Range(1,10).CombineLatest(
+
+            var cts = new CancellationTokenSource();
+
+            var token = cts.Token;
+
+            FooAsync(token).ForEachAsync(x => { }, token);
 
 
-
+            // Observable.Range(1,10).CombineLatest(
-
 
         }
 

src/UniTask.NetCoreTests/Linq/Projection.cs

@@ -319,5 +319,86 @@ namespace NetCoreTests.Linq
                 await Assert.ThrowsAsync<UniTaskTestException>(async () => await ys);
             }
         }
+
+        [Fact]
+        public async Task CombineLatestOK()
+        {
+            var a = new AsyncReactiveProperty<int>(0);
+            var b = new AsyncReactiveProperty<int>(0);
+
+            var list = new List<(int, int)>();
+            var complete = a.WithoutCurrent().CombineLatest(b.WithoutCurrent(), (x, y) => (x, y)).ForEachAsync(x => list.Add(x));
+
+            list.Count.Should().Be(0);
+
+            a.Value = 10;
+            list.Count.Should().Be(0);
+
+            a.Value = 20;
+            list.Count.Should().Be(0);
+
+            b.Value = 1;
+            list.Count.Should().Be(1);
+
+            list[0].Should().Be((20, 1));
+
+            a.Value = 30;
+            list.Last().Should().Be((30, 1));
+
+            b.Value = 2;
+            list.Last().Should().Be((30, 2));
+
+            a.Dispose();
+            b.Value = 3;
+            list.Last().Should().Be((30, 3));
+
+            b.Dispose();
+
+            await complete;
+        }
+
+        [Fact]
+        public async Task CombineLatestLong()
+        {
+            var a = UniTaskAsyncEnumerable.Range(1, 100000);
+            var b = new AsyncReactiveProperty<int>(0);
+
+            var list = new List<(int, int)>();
+            var complete = a.CombineLatest(b.WithoutCurrent(), (x, y) => (x, y)).ForEachAsync(x => list.Add(x));
+
+            b.Value = 1;
+
+            list[0].Should().Be((100000, 1));
+
+            b.Dispose();
+
+            await complete;
+        }
+
+        [Fact]
+        public async Task CombineLatestError()
+        {
+            var a = new AsyncReactiveProperty<int>(0);
+            var b = new AsyncReactiveProperty<int>(0);
+
+            var list = new List<(int, int)>();
+            var complete = a.WithoutCurrent()
+                .Select(x => { if (x == 0) { throw new MyException(); } return x; })
+                .CombineLatest(b.WithoutCurrent(), (x, y) => (x, y)).ForEachAsync(x => list.Add(x));
+
+
+            a.Value = 10;
+            b.Value = 1;
+            list.Last().Should().Be((10, 1));
+
+            a.Value = 0;
+
+            await Assert.ThrowsAsync<MyException>(async () => await complete);
+        }
+
+        class MyException : Exception
+        {
+
+        }
     }
 }

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/CombineLatest.cs.meta

@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: 6cb07f6e88287e34d9b9301a572284a5
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/CombineLatest.tt

@@ -0,0 +1,212 @@
+<#@ template debug="false" hostspecific="false" language="C#" #>
+<#@ assembly name="System.Core" #>
+<#@ import namespace="System.Linq" #>
+<#@ import namespace="System.Text" #>
+<#@ import namespace="System.Collections.Generic" #>
+<#@ output extension=".cs" #>
+<#
+    var tMax = 15;
+    Func<int, string> typeArgs = x => string.Join(", ", Enumerable.Range(1, x).Select(x => $"T{x}")) + ", TResult";
+    Func<int, string> paramArgs = x => string.Join(", ", Enumerable.Range(1, x).Select(x => $"IUniTaskAsyncEnumerable<T{x}> source{x}"));
+    Func<int, string> parameters = x => string.Join(", ", Enumerable.Range(1, x).Select(x => $"source{x}"));
+
+
+#>
+using Cysharp.Threading.Tasks.Internal;
+using System;
+using System.Threading;
+
+namespace Cysharp.Threading.Tasks.Linq
+{
+    public static partial class UniTaskAsyncEnumerable
+    {
+<# for(var i = 1; i <= tMax; i++) { #>
+        public static IUniTaskAsyncEnumerable<TResult> CombineLatest<<#= typeArgs(i) #>>(this <#= paramArgs(i) #>, Func<<#= typeArgs(i) #>> resultSelector)
+        {
+<# for(var j = 1; j <= i; j++) { #>
+            Error.ThrowArgumentNullException(source<#= j #>, nameof(source<#= j #>));
+<# } #>
+            Error.ThrowArgumentNullException(resultSelector, nameof(resultSelector));
+
+            return new CombineLatest<<#= typeArgs(i) #>>(<#= parameters(i) #>, resultSelector);
+        }
+
+<# } #>
+    }
+
+<# for(var i = 1; i <= tMax; i++) { #>
+    internal class CombineLatest<<#= typeArgs(i) #>> : IUniTaskAsyncEnumerable<TResult>
+    {
+<# for(var j = 1; j <= i; j++) { #>
+        readonly IUniTaskAsyncEnumerable<T<#= j #>> source<#= j #>;
+<# } #>        
+        readonly Func<<#= typeArgs(i) #>> resultSelector;
+
+        public CombineLatest(<#= paramArgs(i) #>, Func<<#= typeArgs(i) #>> resultSelector)
+        {
+<# for(var j = 1; j <= i; j++) { #>
+            this.source<#= j #> = source<#= j #>;
+<# } #>        
+            this.resultSelector = resultSelector;
+        }
+
+        public IUniTaskAsyncEnumerator<TResult> GetAsyncEnumerator(CancellationToken cancellationToken = default)
+        {
+            return new _CombineLatest(<#= parameters(i) #>, resultSelector, cancellationToken);
+        }
+
+        class _CombineLatest : MoveNextSource, IUniTaskAsyncEnumerator<TResult>
+        {
+<# for(var j = 1; j <= i; j++) { #>
+            static readonly Action<object> Completed<#= j #>Delegate = Completed<#= j #>;
+<# } #>
+            const int CompleteCount = <#= i #>;
+
+<# for(var j = 1; j <= i; j++) { #>
+            readonly IUniTaskAsyncEnumerable<T<#= j #>> source<#= j #>;
+<# } #>       
+            readonly Func<<#= typeArgs(i) #>> resultSelector;
+            CancellationToken cancellationToken;
+
+<# for(var j = 1; j <= i; j++) { #>
+            IUniTaskAsyncEnumerator<T<#= j #>> enumerator<#= j #>;
+            UniTask<bool>.Awaiter awaiter<#= j #>;
+            bool hasCurrent<#= j #>;
+            bool running<#= j #>;
+            T<#= j #> current<#= j #>;
+
+<# } #>
+
+            int completedCount;
+            bool syncRunning;
+            TResult result;
+
+            public _CombineLatest(<#= paramArgs(i) #>, Func<<#= typeArgs(i) #>> resultSelector, CancellationToken cancellationToken)
+            {
+<# for(var j = 1; j <= i; j++) { #>
+                this.source<#= j #> = source<#= j #>;
+<# } #>                
+                this.resultSelector = resultSelector;
+                this.cancellationToken = cancellationToken;
+            }
+
+            public TResult Current => result;
+
+            public UniTask<bool> MoveNextAsync()
+            {
+                cancellationToken.ThrowIfCancellationRequested();
+                if (completedCount == CompleteCount) return CompletedTasks.False;
+
+                if (enumerator1 == null)
+                {
+<# for(var j = 1; j <= i; j++) { #>
+                    enumerator<#= j #> = source<#= j #>.GetAsyncEnumerator(cancellationToken);
+<# } #>
+                }
+
+                completionSource.Reset();
+
+                AGAIN:
+                syncRunning = true;
+<# for(var j = 1; j <= i; j++) { #>
+                if (!running<#= j #>)
+                {
+                    running<#= j #> = true;
+                    awaiter<#= j #> = enumerator<#= j #>.MoveNextAsync().GetAwaiter();
+                    awaiter<#= j #>.SourceOnCompleted(Completed<#= j #>Delegate, this);
+                }
+<# } #>
+
+                if (<#= string.Join(" || ", Enumerable.Range(1, i).Select(x => $"!running{x}")) #>)
+                {
+                    goto AGAIN;
+                }
+                syncRunning = false;
+
+                return new UniTask<bool>(this, completionSource.Version);
+            }
+
+<# for(var j = 1; j <= i; j++) { #>
+            static void Completed<#= j #>(object state)
+            {
+                var self = (_CombineLatest)state;
+                self.running<#= j #> = false;
+
+                try
+                {
+                    if (self.awaiter<#= j #>.GetResult())
+                    {
+                        self.hasCurrent<#= j #> = true;
+                        self.current<#= j #> = self.enumerator<#= j #>.Current;
+                        goto SUCCESS;
+                    }
+                    else
+                    {
+                        if (Interlocked.Increment(ref self.completedCount) == CompleteCount)
+                        {
+                            goto COMPLETE;
+                        }
+                        self.running<#= j #> = true; // as complete.
+                        return;
+                    }
+                }
+                catch (Exception ex)
+                {
+                    self.completedCount = CompleteCount;
+                    self.completionSource.TrySetException(ex);
+                    return;
+                }
+
+                SUCCESS:
+                if (!self.TrySetResult())
+                {
+                    if (self.syncRunning) return;
+                    try
+                    {
+                        self.awaiter<#= j #> = self.enumerator<#= j #>.MoveNextAsync().GetAwaiter();
+                    }
+                    catch (Exception ex)
+                    {
+                        self.completedCount = CompleteCount;
+                        self.completionSource.TrySetException(ex);
+                        return;
+                    }
+
+                    self.awaiter<#= j #>.SourceOnCompleted(Completed<#= j #>Delegate, self);
+                }
+                return;
+                COMPLETE:
+                self.completionSource.TrySetResult(false);
+                return;
+            }
+
+<# } #>
+
+            bool TrySetResult()
+            {
+                if (<#= string.Join(" && ", Enumerable.Range(1, i).Select(x => $"hasCurrent{x}")) #>)
+                {
+                    result = resultSelector(<#= string.Join(", ", Enumerable.Range(1, i).Select(x => $"current{x}")) #>);
+                    completionSource.TrySetResult(true);
+                    return true;
+                }
+                else
+                {
+                    return false;
+                }
+            }
+
+            public async UniTask DisposeAsync()
+            {
+<# for(var j = 1; j <= i; j++) { #>
+                if (enumerator<#= j #> != null)
+                {
+                    await enumerator<#= j #>.DisposeAsync();
+                }
+<# } #>                
+            }
+        }
+    }
+
+<# } #>
+}

src/UniTask/Assets/Plugins/UniTask/Runtime/Linq/CombineLatest.tt.meta

@@ -0,0 +1,7 @@
+fileFormatVersion: 2
+guid: b1b8cfa9d17af814a971ee2224aaaaa2
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

src/UniTask/Assets/Scenes/SandboxMain.cs

@@ -276,6 +276,8 @@ public class SandboxMain : MonoBehaviour
 
 
         
+
+
         okButton.OnClickAsAsyncEnumerable().ForEachAsync(_ =>
         {