Std\Tuple

Operations on 2-tuples (pairs).

Tuples are the built-in product type (a, b). This module provides accessors, transformers, and conversion functions.

Functions

Returns the first element of a pair.

fst (1, 2)   # => 1

Returns the second element of a pair.

snd (1, 2)   # => 2

Swaps the elements of a pair.

swap (1, 2)   # => (2, 1)

Applies two functions to the respective elements.

mapBoth (\x -> x + 1) (\x -> x * 2) (3, 5)   # => (4, 10)

Transforms the first element, keeping the second unchanged.

mapFst (\x -> x * 10) (3, 5)   # => (30, 5)

Transforms the second element, keeping the first unchanged.

mapSnd (\x -> x * 10) (3, 5)   # => (3, 50)

Converts a pair to a two-element sequence.

toList (1, 2)   # => [1, 2]

Converts a function taking a pair into one taking two arguments.

let add = \(a, b) -> a + b in curry add 3 4   # => 7

Converts a function taking two arguments into one taking a pair.

let add = \a b -> a + b in uncurry add (3, 4)   # => 7