git.r.bdr.sh - rbdr/dotfiles/blob

   1 // Taken from: https://github.com/paulmillr/es6-shim/
   2
   3 'use strict';
   4
   5 var toInteger  = require('../../../number/to-integer')
   6   , toPosInt   = require('../../../number/to-pos-integer')
   7   , validValue = require('../../../object/valid-value')
   8
   9   , hasOwnProperty = Object.prototype.hasOwnProperty
  10   , max = Math.max, min = Math.min;
  11
  12 module.exports = function (target, start/*, end*/) {
  13         var o = validValue(this), end = arguments[2], l = toPosInt(o.length)
  14           , to, from, fin, count, direction;
  15
  16         target = toInteger(target);
  17         start = toInteger(start);
  18         end = (end === undefined) ? l : toInteger(end);
  19
  20         to = target < 0 ? max(l + target, 0) : min(target, l);
  21         from = start < 0 ? max(l + start, 0) : min(start, l);
  22         fin = end < 0 ? max(l + end, 0) : min(end, l);
  23         count = min(fin - from, l - to);
  24         direction = 1;
  25
  26         if ((from < to) && (to < (from + count))) {
  27                 direction = -1;
  28                 from += count - 1;
  29                 to += count - 1;
  30         }
  31         while (count > 0) {
  32                 if (hasOwnProperty.call(o, from)) o[to] = o[from];
  33                 else delete o[from];
  34                 from += direction;
  35                 to += direction;
  36                 count -= 1;
  37         }
  38         return o;
  39 };