Source code in the ocaml programming language

type tree = Empty
          | Leaf of int
          | Node of tree * tree

let t1 = Node (Leaf 1, Node (Leaf 2, Leaf 3))


type point = { x : int; y : int }


let p = { x = 4; y = 5 }


p.x (* evaluates to 4 *)


type mutable_point = { mutable x2 : int; mutable y2 : int }


let p2 = { x2 = 4; y2 = 5 } in
  p2.x2 <- 6;
  p2 (* evaluates to { x2 = 6; y2 = 5 } *)


let p = (2,3)