Merge pull request fsprojects#108 from mattstermiller/fsprojects#11-return-misleading

Changes computation expression's Return to accept only unit.

Author: dsyme

src/FSharp.Control.AsyncSeq/AsyncSeq.fs

@@ -443,7 +443,7 @@ module AsyncSeq =
     //     do! something
     //
     // because F# translates body as Bind(something, fun () -> Return())
-    member x.Return _ = empty
+    member x.Return () = empty
     member x.YieldFrom(s:AsyncSeq<'T>) =
       s
     member x.Zero () = empty

src/FSharp.Control.AsyncSeq/AsyncSeq.fsi

@@ -90,9 +90,6 @@ module AsyncSeq =
         /// also the AsyncSeq.collect function.
         member For : source:AsyncSeq<'T> * action:('T -> AsyncSeq<'TResult>) -> AsyncSeq<'TResult>
 
-        /// Implements "return" for the asyncSeq computation builder.
-        member Return : 'unit -> AsyncSeq<'T>
-
         /// Implements "try-finally" for the asyncSeq computation builder.
         member TryFinally : body:AsyncSeq<'T> * compensation:(unit -> unit) -> AsyncSeq<'T>
 

tests/FSharp.Control.AsyncSeq.Tests/AsyncSeqTests.fs

@@ -1710,7 +1710,9 @@ let ``AsyncSeq.ofAsyncEnum should roundtrip successfully``() =
 let ``AsyncSeq.toAsyncEnum raises exception``() : unit =
   async {
     let exceptionMessage = "Raised inside AsyncSeq"
-    let exceptionSequence = asyncSeq { yield failwith exceptionMessage; yield 1 } |> AsyncSeq.toAsyncEnum
+    let exceptionSequence = 
+      asyncSeq { yield failwith exceptionMessage; yield 1 } 
+      |> AsyncSeq.toAsyncEnum
     let mutable exceptionRaised = false
     try
       let enumerator = exceptionSequence.GetAsyncEnumerator()
@@ -1729,7 +1731,10 @@ let ``AsyncSeq.toAsyncEnum raises exception``() : unit =
 let ``AsyncSeq.ofAsyncEnum raises exception``() : unit =
   async {
     let exceptionMessage = "Raised inside AsyncSeq"
-    let exceptionSequence = asyncSeq { return failwith exceptionMessage; yield 1 } |> AsyncSeq.toAsyncEnum |> AsyncSeq.ofAsyncEnum
+    let exceptionSequence = 
+      asyncSeq { yield failwith exceptionMessage; yield 1 } 
+      |> AsyncSeq.toAsyncEnum 
+      |> AsyncSeq.ofAsyncEnum
     let mutable exceptionRaised = false
     try
       let enumerator = exceptionSequence.GetEnumerator()