| Copyright | Nils Anders Danielsson 2006 , Alexander Berntsen 2014 |
|---|---|
| License | BSD-style (see the LICENSE file in the distribution) |
| Maintainer | libraries@haskell.org |
| Stability | experimental |
| Portability | portable |
| Safe Haskell | Trustworthy |
| Language | Haskell2010 |
Data.Function
Contents
- Prelude re-exports
- Other combinators
Description
Simple combinators working solely on and with functions.
Prelude re-exports
id :: a -> a
Identity function.
const :: a -> b -> a
Constant function.
(.) :: (b -> c) -> (a -> b) -> a -> c infixr 9
Function composition.
flip :: (a -> b -> c) -> b -> a -> c
takes its (first) two arguments in the reverse order of flip ff.
($) :: (a -> b) -> a -> b infixr 0
Application operator. This operator is redundant, since ordinary
application (f x) means the same as (f . However, $ x)$ 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 ,
or map ($ 0) xs.zipWith ($) fs xs
Other combinators
(&) :: a -> (a -> b) -> b infixl 1