(a -> b) -> m a -> m b

fmapDefault :: Traversable t => (a -> b) -> t a -> t b
base Data.Traversable
This function may be used as a value for fmap in a Functor instance.
fmap :: Functor f => (a -> b) -> f a -> f b
base Prelude, base Data.Functor, base Control.Monad, base Control.Monad.Instances
(<$>) :: Functor f => (a -> b) -> f a -> f b
base Data.Functor, base Control.Applicative
An infix synonym for fmap.
liftA :: Applicative f => (a -> b) -> f a -> f b
base Control.Applicative
Lift a function to actions. This function may be used as a value for fmap in a Functor instance.
liftM :: Monad m => (a1 -> r) -> m a1 -> m r
base Control.Monad
Promote a function to a monad.
map :: (a -> b) -> IntMap a -> IntMap b
containers Data.IntMap.Strict, containers Data.IntMap.Lazy
O(n). Map a function over all values in the map. > map (++ "x") (fromList [(5,"a"), (3,"b")]) == fromList [(3, "bx"), (5, "ax")]
mapMonotonic :: (a -> b) -> Set a -> Set b
containers Data.Set
O(n). The mapMonotonic f s == map f s, but works only when f is monotonic. The precondition is not checked. Semi-formally, we have: > and [x < y ==> f x < f y | x <- ls, y <- ls] > ==> mapMonotonic f s == map f s >  
map :: (a -> b) -> [a] -> [b]
base Prelude, base Data.List
map f xs is the list obtained by applying f to each element of xs, i.e., > map f [x1, x2, ..., xn] == [f x1, f x2, ..., f xn] > map f [x1, x2, ...] == [f x1, f x2, ...]
(<*>) :: Applicative f => f (a -> b) -> f a -> f b
base Control.Applicative
ap :: Monad m => m (a -> b) -> m a -> m b
base Control.Monad
In many situations, the liftM operations can be replaced by uses of ap, which promotes function application. > return f `ap` x1 `ap` ... `ap` xn is equivalent to > liftMn f x1 x2 ... xn
(<**>) :: Applicative f => f a -> f (a -> b) -> f b
base Control.Applicative
A variant of <*> with the arguments reversed.
parMap :: Strategy b -> (a -> b) -> [a] -> [b]
parallel Control.Parallel.Strategies
A combination of parList and map, encapsulating a common pattern: > parMap strat f = withStrategy (parList strat) . map f
($) :: (a -> b) -> a -> b
base Prelude, base Data.Function
Application operator. This operator is redundant, since ordinary application (f x) means the same as (f $ x). However, $ has low, right-associative binding precedence, so it sometimes allows parentheses to be omitted; for example: > f $ g $ h x = f (g (h x)) It is also useful in higher-order situations, such as map ($ 0) xs, or Data.List.zipWith ($) fs xs.
($!) :: (a -> b) -> a -> b
base Prelude
Strict (call-by-value) application, defined in terms of seq.
adjust :: (a -> a) -> Int -> Seq a -> Seq a
containers Data.Sequence
O(log(min(i,n-i))). Update the element at the specified position. If the position is out of range, the original sequence is returned.
foldMapDefault :: (Traversable t, Monoid m) => (a -> m) -> t a -> m
base Data.Traversable
This function may be used as a value for Data.Foldable.foldMap in a Foldable instance.
foldMap :: (Foldable t, Monoid m) => (a -> m) -> t a -> m
base Data.Foldable
adjust :: (a -> a) -> Key -> IntMap a -> IntMap a
containers Data.IntMap.Strict, containers Data.IntMap.Lazy
O(min(n,W)). Adjust a value at a specific key. When the key is not a member of the map, the original map is returned. > adjust ("new " ++) 5 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "new a")] > adjust ("new " ++) 7 (fromList [(5,"a"), (3,"b")]) == fromList [(3, "b"), (5, "a")] > adjust ("new " ++) 7 empty == empty
maybe :: b -> (a -> b) -> Maybe a -> b
base Prelude, base Data.Maybe
The maybe function takes a default value, a function, and a Maybe value. If the Maybe value is Nothing, the function returns the default value. Otherwise, it applies the function to the value inside the Just and returns the result.
map :: (Ord a, Ord b) => (a -> b) -> Set a -> Set b
containers Data.Set
O(n*log n). map f s is the set obtained by applying f to each element of s. It's worth noting that the size of the result may be smaller if, for some (x,y), x /= y && f x == f y

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