Use Microsoft.Bcl.AsyncInterfaces in netstandard2.0 (#39)

* Use Microsoft.Bcl.AsyncInterfaces in netstandard2.0

* Make own IAsyncEnumerable

* Fix AsyncEx IAsyncEnum impl

* Fix stalling

build/build.fs

@@ -238,7 +238,6 @@ module DocsTool =
     let build (configuration) =
         Fsdocs.build fsDocsDotnetOptions (fsDocsBuildParams configuration)
 
-
     let watch (configuration) =
         let buildParams bp =
             let bp =
@@ -276,7 +275,7 @@ let maxCpuMsBuild =
     lazy
         (match maxCpuCount.Value with
          | None -> ""
-         | Some None -> "/m:"
+         | Some None -> "/m"
          | Some(Some x) -> $"/m:%d{x}")
 
 let allPublishChecks () =

paket.dependencies

@@ -7,6 +7,7 @@ nuget FSharp.Core >= 6.0.1
 nuget Microsoft.SourceLink.GitHub 1.1.1 copy_local: true
 nuget BenchmarkDotNet >= 0.13.9
 nuget Ply >= 0.3.1
+nuget Microsoft.Bcl.AsyncInterfaces >= 6.0.0 framework:netstandard2.0
 
 
 group Test
@@ -15,6 +16,7 @@ group Test
   source https://api.nuget.org/v3/index.json
   nuget Expecto >= 10.1.0
   nuget Microsoft.Bcl.TimeProvider
+  nuget Microsoft.Bcl.AsyncInterfaces >= 8
   nuget TimeProviderExtensions
   nuget YoloDev.Expecto.TestSdk >= 0.14.2
   nuget Microsoft.NET.Test.Sdk >= 17.7.2

paket.lock

@@ -24,8 +24,8 @@ NUGET
     FSharp.Core (6.0.1)
     Gee.External.Capstone (2.3) - restriction: >= netstandard2.0
     Iced (1.17) - restriction: >= netstandard2.0
-    Microsoft.Bcl.AsyncInterfaces (1.1) - restriction: >= netstandard2.0
-      System.Threading.Tasks.Extensions (>= 4.5.2) - restriction: || (>= net461) (&& (< netcoreapp2.1) (>= netstandard2.0) (< netstandard2.1)) (&& (< netcoreapp2.1) (>= netstandard2.1))
+    Microsoft.Bcl.AsyncInterfaces (6.0) - restriction: == netstandard2.0
+      System.Threading.Tasks.Extensions (>= 4.5.4) - restriction: || (>= net461) (&& (>= netstandard2.0) (< netstandard2.1))
     Microsoft.Build.Tasks.Git (1.1.1) - copy_local: true
     Microsoft.CodeAnalysis.Analyzers (3.3.3) - restriction: >= netstandard2.0
     Microsoft.CodeAnalysis.Common (4.1) - restriction: >= netstandard2.0
@@ -112,7 +112,7 @@ NUGET
     System.Text.Encoding.CodePages (4.5.1) - restriction: >= netstandard2.0
       Microsoft.NETCore.Platforms (>= 2.1.2) - restriction: && (>= netcoreapp2.0) (< xamarinios) (< xamarinmac) (< xamarintvos) (< xamarinwatchos)
       System.Runtime.CompilerServices.Unsafe (>= 4.5.2) - restriction: || (&& (< net46) (< netcoreapp2.0) (>= netstandard2.0) (< xamarinios) (< xamarinmac) (< xamarintvos) (< xamarinwatchos)) (>= net461) (&& (>= netcoreapp2.0) (< xamarinios) (< xamarinmac) (< xamarintvos) (< xamarinwatchos))
-    System.Threading.Tasks.Extensions (4.5.4) - restriction: || (&& (< netcoreapp2.1) (>= netstandard2.1)) (>= netstandard2.0)
+    System.Threading.Tasks.Extensions (4.5.4) - restriction: >= netstandard2.0
       System.Runtime.CompilerServices.Unsafe (>= 4.5.3) - restriction: || (&& (< monoandroid) (< monotouch) (< net45) (>= netstandard1.0) (< netstandard2.0) (< win8) (< wpa81) (< xamarintvos) (< xamarinwatchos)) (&& (< monoandroid) (< netstandard1.0) (>= portable-net45+win8+wp8+wpa81) (< win8)) (&& (>= net45) (< netstandard2.0)) (&& (< net45) (< netcoreapp2.1) (>= netstandard2.0) (< xamarinios) (< xamarinmac) (< xamarintvos) (< xamarinwatchos)) (>= net461) (&& (< netstandard1.0) (>= win8)) (&& (< netstandard2.0) (>= wpa81)) (>= wp8)
 
 GROUP Build
@@ -367,7 +367,7 @@ NUGET
     FSharp.Control.TaskSeq (0.3)
       FSharp.Core (>= 6.0.2) - restriction: >= netstandard2.1
     FSharp.Core (7.0.401) - restriction: >= netstandard2.1
-    Microsoft.Bcl.AsyncInterfaces (7.0) - restriction: || (>= net462) (&& (< net8.0) (>= netstandard2.0))
+    Microsoft.Bcl.AsyncInterfaces (8.0)
       System.Threading.Tasks.Extensions (>= 4.5.4) - restriction: || (>= net462) (&& (>= netstandard2.0) (< netstandard2.1))
     Microsoft.Bcl.TimeProvider (8.0)
       Microsoft.Bcl.AsyncInterfaces (>= 6.0) - restriction: || (>= net462) (&& (< net8.0) (>= netstandard2.0))

src/IcedTasks/AsyncEx.fs

@@ -155,7 +155,6 @@ type AsyncEx =
                 )
                 |> ignore
         )
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
 
 
     /// <summary>
@@ -191,7 +190,6 @@ type AsyncEx =
         else
             AsyncEx.AwaitTask(vTask.AsTask())
 
-#endif
 
 /// <exclude/>
 [<AutoOpen>]
@@ -274,19 +272,13 @@ type AsyncExBuilder() =
     member inline _.Bind(computation: Async<'f>, [<InlineIfLambda>] binder: 'f -> Async<'f0>) =
         async.Bind(computation, binder)
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
-
-    member inline _.TryFinallyAsync
+    member inline this.TryFinallyAsync
         (
             computation: Async<'ok>,
             [<InlineIfLambda>] compensation: unit -> ValueTask
         ) : Async<'ok> =
 
-        let compensation =
-            async {
-                let vTask = compensation ()
-                return! Async.AwaitValueTask vTask
-            }
+        let compensation = this.Delay(fun () -> AsyncEx.AwaitValueTask(compensation ()))
 
         Async.TryFinallyAsync(computation, compensation)
 
@@ -331,14 +323,13 @@ type AsyncExBuilder() =
                                 enumerator.MoveNextAsync()
                                 |> AsyncEx.AwaitValueTask
                             )),
-                            (body enumerator.Current)
+                            (this.Delay(fun () -> body enumerator.Current))
                         )
 
                     )
                 )
         )
 
-#endif
     member inline _.While([<InlineIfLambda>] guard: unit -> bool, computation: Async<unit>) =
         async.While(guard, computation)
 
@@ -412,9 +403,8 @@ module AsyncExExtensionsHighPriority =
 
     type AsyncExBuilder with
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
         member inline _.Source(seq: #IAsyncEnumerable<_>) = seq
-#endif
+
         // Required because SRTP can't determine the type of the awaiter
         //     Candidates:
         //  - Task.GetAwaiter() : Runtime.CompilerServices.TaskAwaiter
@@ -423,11 +413,10 @@ module AsyncExExtensionsHighPriority =
 
         member inline _.Source(task: Task) = AsyncEx.AwaitTask task
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
         member inline _.Source(vtask: ValueTask<_>) = AsyncEx.AwaitValueTask vtask
 
         member inline _.Source(vtask: ValueTask) = AsyncEx.AwaitValueTask vtask
-#endif
+
 namespace IcedTasks.Polyfill.Async
 
 /// <namespacedoc>

src/IcedTasks/CancellableTask.fs

@@ -377,12 +377,7 @@ module CancellableTasks =
         /// followed by "Tasks Finished".
         /// </example>
         let inline getCancellationToken () =
-            fun (ct: CancellationToken) ->
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
-                ValueTask<CancellationToken> ct
-#else
-                Task.FromResult ct
-#endif
+            fun (ct: CancellationToken) -> ValueTask<CancellationToken> ct
 
         /// <summary>Lifts an item to a CancellableTask.</summary>
         /// <param name="item">The item to be the result of the CancellableTask.</param>

src/IcedTasks/CancellableTaskBuilderBase.fs

@@ -194,7 +194,7 @@ module CancellableTaskBase =
                 body: 'T -> CancellableTaskBaseCode<'TOverall, unit, 'Builder>
             ) : CancellableTaskBaseCode<'TOverall, unit, 'Builder> =
             ResumableCode.For(sequence, body)
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
+
         /// <summary>Creates A CancellableTask that runs computation. The action compensation is executed
         /// after computation completes, whether computation exits normally or by an exception. If compensation raises an exception itself
         /// the original exception is discarded and the new exception becomes the overall result of the computation.</summary>
@@ -379,8 +379,6 @@ module CancellableTaskBase =
                     )
                     .Invoke(&sm)
             )
-#endif
-
 
     /// <exclude/>
     [<AutoOpen>]
@@ -764,14 +762,12 @@ module CancellableTaskBase =
         // High priority extensions
         type CancellableTaskBuilderBase with
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
             /// <summary>Allows the computation expression to turn other types into other types</summary>
             ///
             /// <remarks>This is the identify function for For binds.</remarks>
             ///
             /// <returns>IEnumerable</returns>
             member inline _.Source(s: #IAsyncEnumerable<_>) = s
-#endif
 
             /// <summary>Allows the computation expression to turn other types into CancellationToken -> 'Awaiter</summary>
             ///

src/IcedTasks/CancellableValueTask.fs

@@ -11,7 +11,6 @@
 
 namespace IcedTasks
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
 
 /// Contains methods to build CancellableTasks using the F# computation expression syntax
 [<AutoOpen>]
@@ -456,4 +455,3 @@ module CancellableValueTasks =
             fun ct ->
                 cancellableTask ct
                 |> ValueTask.toUnit
-#endif

src/IcedTasks/ColdTask.fs

@@ -196,7 +196,6 @@ module ColdTasks =
             ) : ColdTaskCode<'TOverall, unit> =
             ResumableCode.For(sequence, body)
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
         /// <summary>Creates an ColdTask that runs computation. The action compensation is executed
         /// after computation completes, whether computation exits normally or by an exception. If compensation raises an exception itself
         /// the original exception is discarded and the new exception becomes the overall result of the computation.</summary>
@@ -287,7 +286,6 @@ module ColdTasks =
                 )
             )
 
-#endif
     /// Contains methods to build ColdTasks using the F# computation expression syntax
     type ColdTaskBuilder() =
 

src/IcedTasks/TaskBuilderBase.fs

@@ -164,7 +164,6 @@ module TaskBase =
                 )
             )
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
         /// <summary>Creates a Task that runs computation. The action compensation is executed
         /// after computation completes, whether computation exits normally or by an exception. If compensation raises an exception itself
         /// the original exception is discarded and the new exception becomes the overall result of the computation.</summary>
@@ -345,7 +344,6 @@ module TaskBase =
                     )
                     .Invoke(&sm)
             )
-#endif
 
         /// <summary>Creates a Task that enumerates the sequence seq
         /// on demand and runs body for each element.</summary>
@@ -550,14 +548,12 @@ module TaskBase =
         // High priority extensions
         type TaskBuilderBase with
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
             /// <summary>Allows the computation expression to turn other types into other types</summary>
             ///
             /// <remarks>This is the identify function for For binds.</remarks>
             ///
             /// <returns>IEnumerable</returns>
             member inline _.Source(s: #IAsyncEnumerable<_>) = s
-#endif
 
 
             /// <summary>Allows the computation expression to turn other types into 'Awaiter</summary>

src/IcedTasks/TaskUnit.fs

@@ -41,7 +41,7 @@ module TasksUnit =
         /// <summary>
         /// The entry point for the dynamic implementation of the corresponding operation. Do not use directly, only used when executing quotations that involve tasks or other reflective execution of F# code.
         /// </summary>
-        static member inline RunDynamic(code: TaskBaseCode<'T, 'T, _>) : Task =
+        static member inline RunDynamic(code: TaskBaseCode<'T, 'T, AsyncTaskMethodBuilder>) : Task =
 
             let mutable sm = TaskBaseStateMachine<'T, _>()
 
@@ -58,7 +58,12 @@ module TasksUnit =
                             let step = info.ResumptionFunc.Invoke(&sm)
 
                             if step then
+#if DEBUG
+                                sm.Data.MethodBuilder.SetResult()
+#else
+                                // SRTP fails here for some reason in debug mode
                                 MethodBuilder.SetResult(&sm.Data.MethodBuilder)
+#endif
                             else
                                 let mutable awaiter =
                                     sm.ResumptionDynamicInfo.ResumptionData
@@ -89,7 +94,7 @@ module TasksUnit =
             MethodBuilder.get_Task (&sm.Data.MethodBuilder)
 
         /// Hosts the task code in a state machine and starts the task.
-        member inline _.Run(code: TaskBaseCode<'T, 'T, _>) : Task =
+        member inline _.Run(code: TaskBaseCode<'T, 'T, AsyncTaskMethodBuilder>) : Task =
             if __useResumableCode then
                 __stateMachine<TaskBaseStateMachineData<'T, _>, _>
                     (MoveNextMethodImpl<_>(fun sm ->
@@ -101,7 +106,12 @@ module TasksUnit =
                             let __stack_code_fin = code.Invoke(&sm)
 
                             if __stack_code_fin then
+#if DEBUG
+                                sm.Data.MethodBuilder.SetResult()
+#else
+                                // SRTP fails here for some reason in debug mode
                                 MethodBuilder.SetResult(&sm.Data.MethodBuilder)
+#endif
                         with exn ->
                             __stack_exn <- exn
                         // Run SetException outside the stack unwind, see https://github.com/dotnet/roslyn/issues/26567
@@ -157,7 +167,7 @@ module TasksUnit =
         /// <summary>
         /// Hosts the task code in a state machine and starts the task, executing in the threadpool using Task.Run
         /// </summary>
-        member inline _.Run(code: TaskBaseCode<'T, 'T, _>) =
+        member inline _.Run(code: TaskBaseCode<'T, 'T, AsyncTaskMethodBuilder>) =
             if __useResumableCode then
                 __stateMachine<TaskBaseStateMachineData<'T, _>, _>
                     (MoveNextMethodImpl<_>(fun sm ->
@@ -169,7 +179,12 @@ module TasksUnit =
                             let __stack_code_fin = code.Invoke(&sm)
 
                             if __stack_code_fin then
+#if DEBUG
+                                sm.Data.MethodBuilder.SetResult()
+#else
+                                // SRTP fails here for some reason in debug mode
                                 MethodBuilder.SetResult(&sm.Data.MethodBuilder)
+#endif
                         with exn ->
                             __stack_exn <- exn
                         // Run SetException outside the stack unwind, see https://github.com/dotnet/roslyn/issues/26567

src/IcedTasks/ValueTask.fs

@@ -3,7 +3,6 @@ namespace IcedTasks
 
 open System.Threading.Tasks
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
 
 /// <summary>
 /// Module with extension methods for <see cref="T:System.Threading.Tasks.ValueTask`1"/>.
@@ -310,6 +309,3 @@ module ValueTasks =
                 ValueTask()
             else
                 ValueTask(vtask.AsTask())
-
-
-#endif

src/IcedTasks/ValueTaskUnit.fs

@@ -1,8 +1,6 @@
 namespace IcedTasks
 
 
-#if NETSTANDARD2_1 || NET6_0_OR_GREATER
-
 // Task builder for F# that compiles to allocation-free paths for synchronous code.
 //
 // Originally written in 2016 by Robert Peele ([email protected])
@@ -43,7 +41,9 @@ module ValueTasksUnit =
         /// <summary>
         /// The entry point for the dynamic implementation of the corresponding operation. Do not use directly, only used when executing quotations that involve tasks or other reflective execution of F# code.
         /// </summary>
-        static member inline RunDynamic(code: TaskBaseCode<'T, 'T, _>) : ValueTask =
+        static member inline RunDynamic
+            (code: TaskBaseCode<'T, 'T, AsyncValueTaskMethodBuilder>)
+            : ValueTask =
 
             let mutable sm = TaskBaseStateMachine<'T, _>()
 
@@ -60,7 +60,12 @@ module ValueTasksUnit =
                             let step = info.ResumptionFunc.Invoke(&sm)
 
                             if step then
+#if DEBUG
+                                sm.Data.MethodBuilder.SetResult()
+#else
+                                // SRTP fails here for some reason in debug mode
                                 MethodBuilder.SetResult(&sm.Data.MethodBuilder)
+#endif
                             else
                                 let mutable awaiter =
                                     sm.ResumptionDynamicInfo.ResumptionData
@@ -82,6 +87,7 @@ module ValueTasksUnit =
                         | exn -> MethodBuilder.SetException(&sm.Data.MethodBuilder, exn)
 
                     member _.SetStateMachine(sm, state) =
+
                         MethodBuilder.SetStateMachine(&sm.Data.MethodBuilder, state)
                 }
 
@@ -91,9 +97,9 @@ module ValueTasksUnit =
             MethodBuilder.get_Task (&sm.Data.MethodBuilder)
 
         /// Hosts the task code in a state machine and starts the task.
-        member inline _.Run(code: TaskBaseCode<'T, 'T, _>) : ValueTask =
+        member inline _.Run(code: TaskBaseCode<'T, 'T, AsyncValueTaskMethodBuilder>) : ValueTask =
             if __useResumableCode then
-                __stateMachine<TaskBaseStateMachineData<'T, _>, ValueTask>
+                __stateMachine<TaskBaseStateMachineData<'T, AsyncValueTaskMethodBuilder>, ValueTask>
                     (MoveNextMethodImpl<_>(fun sm ->
                         //-- RESUMABLE CODE START
                         __resumeAt sm.ResumptionPoint
@@ -103,7 +109,12 @@ module ValueTasksUnit =
                             let __stack_code_fin = code.Invoke(&sm)
 
                             if __stack_code_fin then
+#if DEBUG
+                                sm.Data.MethodBuilder.SetResult()
+#else
+                                // SRTP fails here for some reason in debug mode
                                 MethodBuilder.SetResult(&sm.Data.MethodBuilder)
+#endif
                         with exn ->
                             __stack_exn <- exn
                         // Run SetException outside the stack unwind, see https://github.com/dotnet/roslyn/issues/26567
@@ -148,5 +159,3 @@ module ValueTasksUnit =
         /// Builds a valueTask using computation expression syntax.
         /// </summary>
         let vTaskUnit = valueTaskUnit
-
-#endif