some.js 401 Bytes
'use strict';

var callable = require('es5-ext/object/valid-callable')
  , forOf    = require('es6-iterator/for-of')

  , call = Function.prototype.call;

module.exports = function (cb/*, thisArg*/) {
	var thisArg = arguments[1], result = false;
	callable(cb);
	forOf(this, function (value, doBreak) {
		if (call.call(cb, thisArg, value)) {
			result = true;
			doBreak();
		}
	});
	return result;
};