Home - News ( United States | United Kingdom | Italy | Germany ) - Football scores

Showing content from http://hackage.haskell.org/packages/archive/base/4.5.0.0/doc/html/Data-Function.html below:

Data.Function

Description

Simple combinators working solely on and with functions.

Synopsis

• id :: a -> a
• const :: a -> b -> a
• (.) :: (b -> c) -> (a -> b) -> a -> c
• flip :: (a -> b -> c) -> b -> a -> c
• ($) :: (a -> b) -> a -> b
• fix :: (a -> a) -> a
• on :: (b -> b -> c) -> (a -> b) -> a -> a -> c

(.) :: (b -> c) -> (a -> b) -> a -> cSource

Function composition.

flip :: (a -> b -> c) -> b -> a -> cSource

flip f takes its (first) two arguments in the reverse order of f.

($) :: (a -> b) -> a -> bSource

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 zipWith ($) fs xs.

fix :: (a -> a) -> aSource

fix f is the least fixed point of the function f, i.e. the least defined x such that f x = x.

on :: (b -> b -> c) -> (a -> b) -> a -> a -> cSource

(*) `on` f = \x y -> f x * f y.

Typical usage: sortBy (compare `on` fst).

Algebraic properties:

• (*) `on` id = (*) (if (*) ∉ {⊥, const ⊥})

• ((*) `on` f) `on` g = (*) `on` (f . g)

• flip on f . flip on g = flip on (g . f)

RetroSearch is an open source project built by @garambo | Open a GitHub Issue

Search and Browse the WWW like it's 1997 | Search results from DuckDuckGo

HTML: 3.2 | Encoding: UTF-8 | Version: 0.7.4