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add GHC.HetMet.{hetmet_kappa,hetmet_kappa_app}
[ghc-base.git]
/
Data
/
Traversable.hs
diff --git
a/Data/Traversable.hs
b/Data/Traversable.hs
index
2bdc1bc
..
062d1a0
100644
(file)
--- a/
Data/Traversable.hs
+++ b/
Data/Traversable.hs
@@
-170,7
+170,10
@@
instance Applicative (StateR s) where
mapAccumR :: Traversable t => (a -> b -> (a, c)) -> a -> t b -> (a, t c)
mapAccumR f s t = runStateR (traverse (StateR . flip f) t) s
mapAccumR :: Traversable t => (a -> b -> (a, c)) -> a -> t b -> (a, t c)
mapAccumR f s t = runStateR (traverse (StateR . flip f) t) s
--- | This function may be used as a value for `fmap` in a `Functor` instance.
+-- | This function may be used as a value for `fmap` in a `Functor`
+-- instance, provided that 'traverse' is defined. (Using
+-- `fmapDefault` with a `Traversable` instance defined only by
+-- 'sequenceA' will result in infinite recursion.)
fmapDefault :: Traversable t => (a -> b) -> t a -> t b
{-# INLINE fmapDefault #-}
fmapDefault f = getId . traverse (Id . f)
fmapDefault :: Traversable t => (a -> b) -> t a -> t b
{-# INLINE fmapDefault #-}
fmapDefault f = getId . traverse (Id . f)