Merge pull request #1974 from mono/fsharp-completion-bug

[F#] Prevents completion window appearing here`let (x|`

Author: nosami

main/external/fsharpbinding/MonoDevelop.FSharp.Tests/CompletionTests.fs

@@ -69,6 +69,7 @@ type ``Completion Tests``() =
         results |> should contain "completeme"
 
     [<TestCase("let x|")>]
+    [<TestCase("let (x|")>]
     [<TestCase("let! x|")>]
     [<TestCase("let in|")>]
     [<TestCase("let x |")>]

main/external/fsharpbinding/MonoDevelop.FSharpBinding/FSharpTextEditorCompletion.fs

@@ -187,7 +187,7 @@ module Completion =
             None
 
     let (|LetIdentifier|_|) context =
-        if Regex.IsMatch(context.lineToCaret, "\s?(let!?|override|member|for)\s+[^=(]+$", RegexOptions.Compiled) then
+        if Regex.IsMatch(context.lineToCaret, "\s?(let!?|override|member|for)\s+[^=:]+$", RegexOptions.Compiled) then
              Some LetIdentifier
         else
             None