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

   1 'use strict';
   2
   3 var toInteger    = require('../../../number/to-integer')
   4   , toPosInt     = require('../../../number/to-pos-integer')
   5   , isPlainArray = require('../../is-plain-array')
   6
   7   , isArray = Array.isArray, slice = Array.prototype.slice
   8   , hasOwnProperty = Object.prototype.hasOwnProperty, max = Math.max;
   9
  10 module.exports = function (start, end) {
  11         var length, result, i;
  12         if (!this || !isArray(this) || isPlainArray(this)) {
  13                 return slice.apply(this, arguments);
  14         }
  15         length = toPosInt(this.length);
  16         start = toInteger(start);
  17         if (start < 0) start = max(length + start, 0);
  18         else if (start > length) start = length;
  19         if (end === undefined) {
  20                 end = length;
  21         } else {
  22                 end = toInteger(end);
  23                 if (end < 0) end = max(length + end, 0);
  24                 else if (end > length) end = length;
  25         }
  26         if (start > end) start = end;
  27         result = new this.constructor(end - start);
  28         i = 0;
  29         while (start !== end) {
  30                 if (hasOwnProperty.call(this, start)) result[i] = this[start];
  31                 ++i;
  32                 ++start;
  33         }
  34         return result;
  35 };