| module.exports = function (xs, fn) { | |
|     var res = []; | |
|     for (var i = 0; i < xs.length; i++) { | |
|         var x = fn(xs[i], i); | |
|         if (isArray(x)) res.push.apply(res, x); | |
|         else res.push(x); | |
|     } | |
|     return res; | |
| }; | |
| 
 | |
| var isArray = Array.isArray || function (xs) { | |
|     return Object.prototype.toString.call(xs) === '[object Array]'; | |
| };
 |