Tuples

.. highlight:: haskell

fst

fst :: (a, b) -> a

Extract the first component of a pair.

Example:

fst (1,2) 1

snd

snd :: (a, b) -> b

Extract the second component of a pair.

Example:

snd (1,2) 2

swap

swap :: (a, b) -> (b, a)

Swap the components of a pair.

Example:

swap (1,2) (2,1)

curry

curry :: ((a, b) -> c) -> a -> b -> c

curry converts an uncurried function to a curried function.

Example:

curry fst 1 2 1

uncurry

uncurry :: (a -> b -> c) -> (a, b) -> c

uncurry converts a curried function to a function on pairs.

Example:

uncurry (+) (1,2) 3