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| author | David Feuer <david.feuer@gmail.com> | 2015-02-05 17:42:50 -0600 |
|---|---|---|
| committer | Austin Seipp <austin@well-typed.com> | 2015-02-05 17:42:50 -0600 |
| commit | 7cf87fc6928f0252d9f61719e2344e6c69237079 (patch) | |
| tree | c278359497761c1a07481281ce0665f025122d41 /libraries/base/Data/Foldable.hs | |
| parent | ae39c5c040f121947e14877c3ceb47bbe80c0ccb (diff) | |
| download | haskell-7cf87fc6928f0252d9f61719e2344e6c69237079.tar.gz | |
Eta-expand argument to foldr in mapM_ for []
Summary:
This improves performance, at least sometimes--the previous
implementation can be worse than the version in base 4.7. I
have not had the time to run benchmarks and such, but `mapM`
already does this.
Also, inline `mapM_`, like `mapM`.
Reviewers: hvr, nomeata, ekmett, austin
Reviewed By: ekmett, austin
Subscribers: thomie
Projects: #ghc
Differential Revision: https://phabricator.haskell.org/D632
GHC Trac Issues: #10034
Diffstat (limited to 'libraries/base/Data/Foldable.hs')
| -rw-r--r-- | libraries/base/Data/Foldable.hs | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/libraries/base/Data/Foldable.hs b/libraries/base/Data/Foldable.hs index a745f66092..b8b0973a8c 100644 --- a/libraries/base/Data/Foldable.hs +++ b/libraries/base/Data/Foldable.hs @@ -349,7 +349,8 @@ for_ = flip traverse_ -- As of base 4.8.0.0, 'mapM_' is just 'traverse_', specialized to -- 'Monad'. mapM_ :: (Foldable t, Monad m) => (a -> m b) -> t a -> m () -mapM_ f= foldr ((>>) . f) (return ()) +{-# INLINE mapM_ #-} +mapM_ f = foldr (\m n -> f m >> n) (return ()) -- | 'forM_' is 'mapM_' with its arguments flipped. For a version that -- doesn't ignore the results see 'Data.Traversable.forM'. |