Maybe a -> (a -> b) -> b
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.
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.
Strict (call-by-value) application, defined in terms of seq.
An infix synonym for fmap.
Lift a function to actions. This function may be used as a value for fmap in a Functor instance.
This function may be used as a value for Data.Foldable.foldMap in a Foldable instance.
This function may be used as a value for fmap in a Functor instance.
Promote a function to a monad.
Determines whether all elements of the structure satisfy the predicate.
Determines whether any element of the structure satisfies the predicate.
Sequential function application. The argument is evaluated using the given strategy before it is given to the function.
Parallel function application. The argument is evaluated using the given strategy, in parallel with the function application.
the deep analogue of $!. In the expression f $!! x, x is fully evaluated before the function f is applied to it.
Apply a transformation everywhere in bottom-up manner
Apply a transformation everywhere in top-down manner
A variant of <*> with the arguments reversed.
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
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