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Within LTS Haskell 24.31 (ghc-9.10.3)
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backprop Prelude.Backprop.Num Alias for fmapConst.
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backprop Prelude.Backprop.Num Alias for fmap.
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<$ ) :: Functor f => a -> f b -> f acabal-install-solver Distribution.Solver.Compat.Prelude Replace all locations in the input with the same value. The default definition is fmap . const, but this may be overridden with a more efficient version.
Examples
Perform a computation with Maybe and replace the result with a constant value if it is Just:>>> 'a' <$ Just 2 Just 'a' >>> 'a' <$ Nothing Nothing
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<$> ) :: Functor f => (a -> b) -> f a -> f bcabal-install-solver Distribution.Solver.Compat.Prelude An infix synonym for fmap. The name of this operator is an allusion to $. Note the similarities between their types:
($) :: (a -> b) -> a -> b (<$>) :: Functor f => (a -> b) -> f a -> f b
Whereas $ is function application, <$> is function application lifted over a Functor.Examples
Convert from a Maybe Int to a Maybe String using show:>>> show <$> Nothing Nothing
>>> show <$> Just 3 Just "3"
Convert from an Either Int Int to an Either Int String using show:>>> show <$> Left 17 Left 17
>>> show <$> Right 17 Right "17"
Double each element of a list:>>> (*2) <$> [1,2,3] [2,4,6]
Apply even to the second element of a pair:>>> even <$> (2,2) (2,True)
type (k1 :: t1)
:$$$: (k2 :: t2) = ToEM k1 ':$$: ToEM k2clash-prelude Clash.Class.HasDomain.Common No documentation available.
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:$$: ) :: ErrorMessage -> ErrorMessage -> ErrorMessageclash-prelude Clash.Explicit.Prelude Stack two pieces of error message on top of each other.
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:$$: ) :: ErrorMessage -> ErrorMessage -> ErrorMessageclash-prelude Clash.Explicit.Prelude.Safe Stack two pieces of error message on top of each other.
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<$ ) :: Functor f => a -> f b -> f aclash-prelude Clash.HaskellPrelude Replace all locations in the input with the same value. The default definition is fmap . const, but this may be overridden with a more efficient version.
Examples
Perform a computation with Maybe and replace the result with a constant value if it is Just:>>> 'a' <$ Just 2 Just 'a' >>> 'a' <$ Nothing Nothing
(
<$> ) :: Functor f => (a -> b) -> f a -> f bclash-prelude Clash.HaskellPrelude An infix synonym for fmap. The name of this operator is an allusion to $. Note the similarities between their types:
($) :: (a -> b) -> a -> b (<$>) :: Functor f => (a -> b) -> f a -> f b
Whereas $ is function application, <$> is function application lifted over a Functor.Examples
Convert from a Maybe Int to a Maybe String using show:>>> show <$> Nothing Nothing
>>> show <$> Just 3 Just "3"
Convert from an Either Int Int to an Either Int String using show:>>> show <$> Left 17 Left 17
>>> show <$> Right 17 Right "17"
Double each element of a list:>>> (*2) <$> [1,2,3] [2,4,6]
Apply even to the second element of a pair:>>> even <$> (2,2) (2,True)
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:$$: ) :: ErrorMessage -> ErrorMessage -> ErrorMessageclash-prelude Clash.Prelude Stack two pieces of error message on top of each other.