src/promissory-arbiter.js
function map (f, arr) {
    var result = [], i, n;
    for (i = 0, n = arr.length; i < n; i++) {
      result.push(f(arr[i]));
    }
    return result;
  }
function map (f, arr) {
    var result = [], i, n;
    for (i = 0, n = arr.length; i < n; i++) {
      result.push(f(arr[i]));
    }
    return result;
  }
function map ( f , arr ) { var result = [ ] , i , n ; for ( i = 0 , n = arr . length ; i < n ; i ++ ) { result . push ( f ( arr [ i ] ) ) ; } return result ; }
Array.prototype.map is supeeeeer slow. In fact, it is slower than a custom map function, which is usually slower than an inline for loop, but is more maintainable.
Array . prototype . map is supeeeeer slow . In fact it is slower than a custom map function which is usually slower than an inline for loop but is more maintainable .