Safe Haskell | Safe-Inferred |
---|---|
Language | Haskell2010 |
Extra functions for working with pairs and triples. Some of these functions are available in the Control.Arrow module, but here are available specialised to pairs. Some operations work on triples.
Synopsis
- module Data.Tuple
- first :: (a -> a') -> (a, b) -> (a', b)
- second :: (b -> b') -> (a, b) -> (a, b')
- (***) :: (a -> a') -> (b -> b') -> (a, b) -> (a', b')
- (&&&) :: (a -> b) -> (a -> c) -> a -> (b, c)
- dupe :: a -> (a, a)
- both :: (a -> b) -> (a, a) -> (b, b)
- firstM :: Functor m => (a -> m a') -> (a, b) -> m (a', b)
- secondM :: Functor m => (b -> m b') -> (a, b) -> m (a, b')
- fst3 :: (a, b, c) -> a
- snd3 :: (a, b, c) -> b
- thd3 :: (a, b, c) -> c
- first3 :: (a -> a') -> (a, b, c) -> (a', b, c)
- second3 :: (b -> b') -> (a, b, c) -> (a, b', c)
- third3 :: (c -> c') -> (a, b, c) -> (a, b, c')
- curry3 :: ((a, b, c) -> d) -> a -> b -> c -> d
- uncurry3 :: (a -> b -> c -> d) -> (a, b, c) -> d
Documentation
module Data.Tuple
Specialised Arrow
functions
first :: (a -> a') -> (a, b) -> (a', b) Source #
Update the first component of a pair.
first succ (1,"test") == (2,"test")
second :: (b -> b') -> (a, b) -> (a, b') Source #
Update the second component of a pair.
second reverse (1,"test") == (1,"tset")
(***) :: (a -> a') -> (b -> b') -> (a, b) -> (a', b') infixr 3 Source #
Given two functions, apply one to the first component and one to the second.
A specialised version of ***
.
(succ *** reverse) (1,"test") == (2,"tset")
(&&&) :: (a -> b) -> (a -> c) -> a -> (b, c) infixr 3 Source #
Given two functions, apply both to a single argument to form a pair.
A specialised version of &&&
.
(succ &&& pred) 1 == (2,0)
More pair operations
both :: (a -> b) -> (a, a) -> (b, b) Source #
Apply a single function to both components of a pair.
both succ (1,2) == (2,3)
Monadic versions
firstM :: Functor m => (a -> m a') -> (a, b) -> m (a', b) Source #
Update the first component of a pair.
firstM (\x -> [x-1, x+1]) (1,"test") == [(0,"test"),(2,"test")]
secondM :: Functor m => (b -> m b') -> (a, b) -> m (a, b') Source #
Update the second component of a pair.
secondM (\x -> [reverse x, x]) (1,"test") == [(1,"tset"),(1,"test")]
Operations on triple
first3 :: (a -> a') -> (a, b, c) -> (a', b, c) Source #
Update the first component of a triple.
first3 succ (1,1,1) == (2,1,1)
second3 :: (b -> b') -> (a, b, c) -> (a, b', c) Source #
Update the second component of a triple.
second3 succ (1,1,1) == (1,2,1)
third3 :: (c -> c') -> (a, b, c) -> (a, b, c') Source #
Update the third component of a triple.
third3 succ (1,1,1) == (1,1,2)