Added bind operator for Validation

Close #188

Author: ratsclub

src/FsToolkit.ErrorHandling/ValidationOp.fs

@@ -4,7 +4,6 @@ open FsToolkit.ErrorHandling
 
 [<AutoOpen>]
 module Validation =
-
     let inline (<!>)
         ([<InlineIfLambda>] mapper: 'okInput -> 'okOutput)
         (input: Validation<'okInput, 'error>)
@@ -28,3 +27,9 @@ module Validation =
         (input: Result<'okInput, 'error>)
         : Validation<'okOutput, 'error> =
         Validation.apply applier (Validation.ofResult input)
+
+    let inline (>>=)
+        (input: Validation<'okInput, 'error>)
+        ([<InlineIfLambda>] binder: 'okInput -> Validation<'okOutput, 'error>)
+        : Validation<'okOutput, 'error> =
+        Validation.bind binder input

tests/FsToolkit.ErrorHandling.Tests/Validation.fs

@@ -104,14 +104,14 @@ let applyTests =
 let operatorsTests =
 
     testList "Validation Operators Tests" [
-        testCase "map & apply operators"
+        testCase "map, apply & bind operators"
         <| fun _ ->
             createPostRequest
             <!> (lift validLatR)
             <*> (lift validLngR)
             <*> (lift validTweetR)
+            >>= (fun tweet -> Ok tweet)
             |> Expect.hasOkValue validCreatePostRequest
-
         testCase "map^ & apply^ operators"
         <| fun _ ->
             createPostRequest