Pair(3)

✨ NAME ✨

okay so bestie, welcome to the Pair(3) page from the OCaml library 💅 — the module is called Pair, and it is Operations on pairs. no cap.

🧚 Module 🧚

Module Pair

Module Pair
 : sig end

💖 Documentation 💖

Module Pair : sig end

Operations on pairs.

Since 5.4 🎀

---

🎀 Pairs 🎀

• type ('a, 'b) t = 'a * 'b — this is the type for pairs. iconic.
• 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.

---

and that's the whole page, bestie 🫶 — brought to you by OCamldoc, dated 2026-06-22, for Pair(3) 💖