# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
#
--pattern-backward PatternSyn2.Some
--pattern-backward PatternSyn2.JustUnit
--pattern-backward PatternSyn2.SomeUnit
===
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE ViewPatterns    #-}
 module PatternSyn2 where

 pattern Some x <- Just x where Some x = Just x
 pattern JustUnit = Some ()
 pattern SomeUnit <- JustUnit

 foo :: Maybe () -> Maybe ()

-foo (Just ()) = Just ()
+foo (Some ()) = Some ()

-foo (id -> Just ()) = Just ()
+foo (id -> Some ()) = Some ()

-foo (Some ()) = Some ()
+foo JustUnit = JustUnit

-foo JustUnit = JustUnit
+foo SomeUnit = JustUnit