Pair(3)                          OCaml library                         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.



OCamldoc                          2025-11-01                           Pair(3)