bucklescript output using conventional JS keys.

stringKeys.js

// Generated CODE, PLEASE EDIT WITH CARE
'use strict';

var invalid_argument = /* tuple */[
  248,
  "Invalid_argument",
  -3
];

var not_found = /* tuple */[
  248,
  "Not_found",
  -6
];



function height(param) {
  if (param) {
    return param.stringFour;
  }
  else {
    return 0;
  }
}

function create(l, x, d, r) {
  var hl = height(l);
  var hr = height(r);
  return /* Node */{
          "stringZero": l,
          "stringOne": x,
          "stringTwo": d,
          "stringThree": r,
          "stringFour": hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
          length: 5,
          tag: 0
        };
}

function bal(l, x, d, r) {
  var hl = l ? l.stringFour : 0;
  var hr = r ? r.stringFour : 0;
  if (hl > (hr + 2 | 0)) {
    if (l) {
      var lr = l.stringThree;
      var ld = l.stringTwo;
      var lv = l.stringOne;
      var ll = l.stringZero;
      if (height(ll) >= height(lr)) {
        return create(ll, lv, ld, create(lr, x, d, r));
      }
      else if (lr) {
        return create(create(ll, lv, ld, lr.stringZero), lr.stringOne, lr.stringTwo, create(lr.stringThree, x, d, r));
      }
      else {
        throw [
              invalid_argument,
              "Map.bal"
            ];
      }
    }
    else {
      throw [
            invalid_argument,
            "Map.bal"
          ];
    }
  }
  else if (hr > (hl + 2 | 0)) {
    if (r) {
      var rr = r.stringThree;
      var rd = r.stringTwo;
      var rv = r.stringOne;
      var rl = r.stringZero;
      if (height(rr) >= height(rl)) {
        return create(create(l, x, d, rl), rv, rd, rr);
      }
      else if (rl) {
        return create(create(l, x, d, rl.stringZero), rl.stringOne, rl.stringTwo, create(rl.stringThree, rv, rd, rr));
      }
      else {
        throw [
              invalid_argument,
              "Map.bal"
            ];
      }
    }
    else {
      throw [
            invalid_argument,
            "Map.bal"
          ];
    }
  }
  else {
    return /* Node */{
            "stringZero": l,
            "stringOne": x,
            "stringTwo": d,
            "stringThree": r,
            "stringFour": hl >= hr ? hl + 1 | 0 : hr + 1 | 0,
            length: 5,
            tag: 0
          };
  }
}

function add(x, data, param) {
  if (param) {
    var r = param.stringThree;
    var d = param.stringTwo;
    var v = param.stringOne;
    var l = param.stringZero;
    var c = x - v | 0;
    if (c) {
      if (c < 0) {
        return bal(add(x, data, l), v, d, r);
      }
      else {
        return bal(l, v, d, add(x, data, r));
      }
    }
    else {
      return /* Node */{
              "stringZero": l,
              "stringOne": x,
              "stringTwo": data,
              "stringThree": r,
              "stringFour": param.stringFour,
              length: 5,
              tag: 0
            };
    }
  }
  else {
    return /* Node */{
            "stringZero": /* Empty */0,
            "stringOne": x,
            "stringTwo": data,
            "stringThree": /* Empty */0,
            "stringFour": 1,
            length: 5,
            tag: 0
          };
  }
}

function find(x, _param) {
  while(true) {
    var param = _param;
    if (param) {
      var c = x - param.stringOne | 0;
      if (c) {
        _param = c < 0 ? param.stringZero : param.stringThree;
        continue ;
        
      }
      else {
        return param.stringTwo;
      }
    }
    else {
      throw not_found;
    }
  };
}

function test() {
  var m = /* Empty */0;
  for(var i = 0; i<= 1000000; ++i){
    m = add(i, i, m);
  }
  for(var i$1 = 0; i$1<= 1000000; ++i$1){
    find(i$1, m);
  }
  return /* () */0;
}

var start = Date.now();
test(/* () */0);
var end = Date.now();
console.log(end-start);

/*  Not a pure module */