type tree = Leaf | Node(int, tree, tree);

​

let rec sum = (item) => {

  switch (item) {

  | Leaf => 0

  | Node(value, left, right) => value + sum(left) + sum(right);

  }

};

​

let myTree =

  Node(

    1,

    Node(2, Node(4, Leaf, Leaf), Node(6, Leaf, Leaf)),

    Node(3, Node(5, Leaf, Leaf), Node(7, Leaf, Leaf))

  );

​

Js.log(sum(myTree));

// Generated by BUCKLESCRIPT, PLEASE EDIT WITH CARE

'use strict';

​

​

function sum(item) {

  if (item) {

    return (item[0] + sum(item[1]) | 0) + sum(item[2]) | 0;

  } else {

    return 0;

  }

}

​

var myTree = /* Node */[

  1,

  /* Node */[

    2,

    /* Node */[

      4,

      /* Leaf */0,

      /* Leaf */0

    ],

    /* Node */[

      6,

      /* Leaf */0,

      /* Leaf */0

    ]

  ],

  /* Node */[

    3,

    /* Node */[

      5,

      /* Leaf */0,

      /* Leaf */0

    ],

    /* Node */[

      7,

      /* Leaf */0,

      /* Leaf */0

    ]

  ]

];

​

console.log(sum(myTree));

​

exports.sum = sum;

exports.myTree = myTree;

/*  Not a pure module */

​

type tree =

  | Leaf

  | Node of int* tree* tree

let rec sum item =

  match item with

  | Leaf  -> 0

  | ((Node (value,left,right))[@explicit_arity ]) ->

      (value + (sum left)) + (sum right)

let myTree =

  ((Node

      (1,

        ((Node

            (2, ((Node (4, Leaf, Leaf))[@explicit_arity ]),

              ((Node (6, Leaf, Leaf))[@explicit_arity ])))[@explicit_arity ]),

        ((Node

            (3, ((Node (5, Leaf, Leaf))[@explicit_arity ]),

              ((Node (7, Leaf, Leaf))[@explicit_arity ])))[@explicit_arity ])))

  [@explicit_arity ])

let _ = Js.log (sum myTree)