Exploring freeing up the stack for tail-calls with setTimeout

tail-calls.js

/******************************************************************************
                               Without tail-call
 ******************************************************************************/
var times = 0;

function test(n) {
  if (++n >= 10000) {
    if (++times == 100) console.timeEnd('no-tail')
  } else {
    test(n);
  }
}

console.time('no-tail');
for (var i = 0; i < 100; i++) {
  test(0);
}

/******************************************************************************
                               With tail-call
 ******************************************************************************/

var LIMIT = 100;

(function() {
  var stackSize = 0;

  tail = function(fn, args) {
    if (++stackSize > LIMIT) {
      stackSize = 0;
      setTimeout(function() { fn.apply(null, args); }, 0);
    } else {
      fn.apply(null, args);
    }
  };
})();

var times = 0;

function test(n) {
  if (++n >= 10000) {
    if (++times == 100) console.timeEnd('tail-call');
  } else {
    tail(test, [n]);
  }
}

console.time('tail-call');
var taken = 0;
for (var i = 0; i < 100; i++) {
  test(0);
}