# 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-forward PatternSyn1.JustUnit
--pattern-forward PatternSyn1.Some
--pattern-forward PatternSyn1.SomeUni
--pattern-forward PatternSyn1.LeftSomething
--pattern-forward PatternSyn1.JustNot
--adhoc-pattern "SomeAdhoc x = Just x"
--adhoc-pattern "SomeAdhoc2 x <- Just x"
===
 {-# LANGUAGE PatternSynonyms #-}
 {-# LANGUAGE ViewPatterns    #-}
 module PatternSyn1 where

 pattern JustUnit = Just ()
 pattern Some x <- Just x where Some x = Just x
 pattern SomeUni x <- Just x
 pattern JustNot x <- Just (not -> x) where JustNot x = Just (not x)
 pattern LeftSomething <- Left _
 pattern SomeAdhoc x = Just x
 pattern SomeAdhoc2 x = Just x

 foo :: Maybe () -> Maybe ()

-foo JustUnit = JustUnit
+foo (Just ()) = Just ()

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

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

-foo (SomeUni ()) = Just ()
+foo (Just ()) = Just ()

-foo (Some x) = let x = Some () in x
+foo (Just x) = let x = Just () in x

-foo (SomeAdhoc ()) = SomeAdhoc ()
+foo (Just ()) = Just ()

-foo (SomeAdhoc2 ()) = SomeAdhoc2 ()
+foo (Just ()) = SomeAdhoc2 ()

 fooBool :: Maybe Bool -> MaybeBool
-fooBool (JustNot x) = JustNot x
+fooBool (Just (not -> x)) = Just (not x)

 bar :: Either () () -> Either () ()
-bar LeftSomething = Left ()
+bar (Left _) = Left ()