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| author | Herbert Valerio Riedel <hvr@gnu.org> | 2015-10-17 16:47:51 +0200 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2015-10-17 16:51:33 +0200 |
| commit | e8ed2136feea75f4676eb6103acd5bb1bfe35281 (patch) | |
| tree | 156daa80421dfdd923d3fa12c83809458f42d333 /compiler/prelude | |
| parent | 40cbf9aaa16fd263c54e159a4bda3a5682720041 (diff) | |
| download | haskell-e8ed2136feea75f4676eb6103acd5bb1bfe35281.tar.gz | |
Make Monad/Applicative instances MRP-friendly
This patch refactors pure/(*>) and return/(>>) in MRP-friendly way, i.e.
such that the explicit definitions for `return` and `(>>)` match the
MRP-style default-implementation, i.e.
return = pure
and
(>>) = (*>)
This way, e.g. all `return = pure` definitions can easily be grepped and
removed in GHC 8.1;
Test Plan: Harbormaster
Reviewers: goldfire, alanz, bgamari, quchen, austin
Reviewed By: quchen, austin
Subscribers: thomie
Differential Revision: https://phabricator.haskell.org/D1312
Diffstat (limited to 'compiler/prelude')
| -rw-r--r-- | compiler/prelude/PrelRules.hs | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/compiler/prelude/PrelRules.hs b/compiler/prelude/PrelRules.hs index f87dce4798..919a1d51fe 100644 --- a/compiler/prelude/PrelRules.hs +++ b/compiler/prelude/PrelRules.hs @@ -643,11 +643,11 @@ instance Functor RuleM where fmap = liftM instance Applicative RuleM where - pure = return + pure x = RuleM $ \_ _ _ -> Just x (<*>) = ap instance Monad RuleM where - return x = RuleM $ \_ _ _ -> Just x + return = pure RuleM f >>= g = RuleM $ \dflags iu e -> case f dflags iu e of Nothing -> Nothing Just r -> runRuleM (g r) dflags iu e |