deepMap.js

function deepMap(obj, fn, that) {
  var stack = {0: {obj: obj}},
		sp = 0,
		ss = 1,
		scope, keys, i, val;
	while ((scope = stack[sp++])) {
		keys = Object.keys(scope.obj);
		for (i = 0; i < keys.length; i++) {
			val = scope.obj[keys[i]];
			fn.call(that, val, keys[i]);
			if (val && Object(val) === val) {
				stack[ss++] = {obj: val};
			}
		}
		delete stack[sp - 1];
	}
}