+ (Value)Task.recover

Author: gusty

src/FSharpPlus/Extensions/Task.fs

@@ -39,19 +39,6 @@ module Task =
     /// <returns>A Task that is completed successfully with the specified value.</returns>
     let result (value: 'T) : Task<'T> = Task.FromResult value
 
-        
-    /// <summary>Creates a Task that's completed unsuccessfully with the specified exception.</summary>
-    /// <param name="exn">The exception to be raised.</param>
-    /// <returns>A Task that is completed unsuccessfully with the specified exception.</returns>
-    let raise<'T> (exn: exn) : Task<'T> =
-      #if NET5_0_OR_GREATER  
-        Task.FromException<'T> exn
-      #else
-        let tcs = TaskCompletionSource<'T> tcsOptions
-        tcs.SetException exn
-        tcs.Task
-      #endif
-
     /// <summary>Creates a Task that's completed unsuccessfully with the specified exceptions.</summary>
     /// <param name="aex">The AggregateException to be raised.</param>
     /// <returns>A Task that is completed unsuccessfully with the specified exceptions.</returns>
@@ -483,14 +470,30 @@ module Task =
     /// <param name="source">The source task.</param>
     /// <returns>A successful resulting task.</returns>
     /// <remarks>The result is always a successful task, unless the mapping function itself throws an exception.</remarks>
+    #if !NET45
+    let inline recover ([<InlineIfLambda>]mapper: exn -> 'T) (source: Task<'T>) : Task<'T> =
+    #else
     let inline recover (mapper: exn -> 'T) (source: Task<'T>) : Task<'T> =
+    #endif
         #if !NET45
         let source = nullArgCheck (nameof source) source
         #else
         raiseIfNull "source" source
         #endif
 
-        tryWith (fun () -> source) (mapper >> result)
+        tryWith (fun () -> source) (mapper >> Task.FromResult)
+    
+    /// <summary>Creates a Task that's completed unsuccessfully with the specified exception.</summary>
+    /// <param name="exn">The exception to be raised.</param>
+    /// <returns>A Task that is completed unsuccessfully with the specified exception.</returns>
+    let raise<'T> (exn: exn) : Task<'T> =
+      #if NET5_0_OR_GREATER  
+        Task.FromException<'T> exn
+      #else
+        let tcs = TaskCompletionSource<'T> tcsOptions
+        tcs.SetException exn
+        tcs.Task
+      #endif
 
     /// <summary>Maps the exception of a faulted task to another exception.</summary>
     /// <param name="mapper">Mapping function from exception to exception.</param>
@@ -525,8 +528,6 @@ module Task =
         match source with
         | Ok x -> result x
         | Error exn -> raise exn
-
-
 /// Workaround to fix signatures without breaking binary compatibility.
 [<AutoOpen>]
 module Task_v2 =

src/FSharpPlus/Extensions/ValueTask.fs

@@ -42,18 +42,6 @@ module ValueTask =
         tcs.SetResult value
         ValueTask<'T> tcs.Task
     #endif
-
-    /// <summary>Creates a ValueTask that's completed unsuccessfully with the specified exception.</summary>
-    /// <param name="exn">The exception to be raised.</param>
-    /// <returns>A ValueTask that is completed unsuccessfully with the specified exception.</returns>
-    let raise<'T> (exn: exn) : ValueTask<'T> =
-      #if NET5_0_OR_GREATER  
-        ValueTask.FromException<'T> exn
-      #else
-        let tcs = TaskCompletionSource<'T> tcsOptions
-        tcs.SetException exn
-        ValueTask<'T> tcs.Task
-      #endif
 
     /// <summary>Creates a Task that's completed unsuccessfully with the specified exceptions.</summary>
     /// <param name="aex">The AggregateException to be raised.</param>
@@ -391,13 +379,37 @@ module ValueTask =
     /// <returns>A successful resulting task.</returns>
     /// <remarks>The result is always a successful task, unless the mapping function itself throws an exception.</remarks>
     let inline recover ([<InlineIfLambda>]mapper: exn -> 'T) (source: ValueTask<'T>) : ValueTask<'T> =
-        tryWith (mapper >> result) (fun () -> source)
+      #if NET5_0_OR_GREATER  
+        tryWith (mapper >> ValueTask.FromResult) (fun () -> source)
+      #else
+        let fromResult r =
+            let tcs = TaskCompletionSource<'T> tcsOptions
+            tcs.SetResult r
+            ValueTask<'T> tcs.Task
+        tryWith (mapper >> fromResult) (fun () -> source)
+      #endif
+
+    /// <summary>Creates a ValueTask that's completed unsuccessfully with the specified exception.</summary>
+    /// <param name="exn">The exception to be raised.</param>
+    /// <returns>A ValueTask that is completed unsuccessfully with the specified exception.</returns>
+    let raise<'T> (exn: exn) : ValueTask<'T> =
+      #if NET5_0_OR_GREATER  
+        ValueTask.FromException<'T> exn
+      #else
+        let tcs = TaskCompletionSource<'T> tcsOptions
+        tcs.SetException exn
+        ValueTask<'T> tcs.Task
+      #endif
 
     /// <summary>Maps the exception of a faulted task to another exception.</summary>
     /// <param name="mapper">Mapping function from exception to exception.</param>
     /// <param name="source">The source task.</param>
     /// <returns>The resulting task.</returns>
+    #if !NET45
     let inline mapError ([<InlineIfLambda>]mapper: exn -> exn) (source: ValueTask<'T>) : ValueTask<'T> =
+    #else
+    let inline mapError (mapper: exn -> exn) (source: ValueTask<'T>) : ValueTask<'T> =
+    #endif
         if source.IsCompleted then
             match source with
             | Faulted exn -> FromExceptions (AggregateException (mapper exn))