Pair(3)

NAME
Pair - Operations on pairs.

Module
Module Pair

Documentation

Module Pair
 : sig end

Operations on pairs.

Since 5.4

  Pairs

type ('a, 'b) t = 'a * 'b

The type for pairs.

val make : 'a -> 'b -> 'a * 'b

make a b is the pair (a, b) .

val fst : 'a * 'b -> 'a

fst (a, b) is a .

val snd : 'a * 'b -> 'b

snd (a, b) is b .

val swap : 'a * 'b -> 'b * 'a

swap (a, b) is (b, a) .

  Iterators

val fold : ('a -> 'b -> 'c) -> 'a * 'b -> 'c

fold f (a, b) applies f to a and b .

val map : ('a -> 'c) -> ('b -> 'd) -> 'a * 'b -> 'c * 'd

map f g (a, b) applies f to a and g to b .

val iter : ('a -> unit) -> ('b -> unit) -> 'a * 'b -> unit

iter f g (a, b) first applies f to a , and then g to b .

val map_fst : ('a -> 'c) -> 'a * 'b -> 'c * 'b

map_fst f p applies f to p 's first component.

val map_snd : ('b -> 'c) -> 'a * 'b -> 'a * 'c

map_snd f p applies f to p 's second component.

  Predicates and comparisons

val equal : ('a -> 'a -> bool) -> ('b -> 'b -> bool) -> 'a * 'b -> 'a * 'b -> bool

equal eqa eqb (a1, b1) (a2, b2) is true if and only if eqa a1 a2 and eqb b1 b2 are both true .

val compare : ('a -> 'a -> int) -> ('b -> 'b -> int) -> 'a * 'b -> 'a * 'b -> int

compare cmpa cmpb is a total order on pairs using cmpa to compare the first component, and cmpb to compare the second component. It is implemented by a lexicographic order.