Tiny array range api

range.js

/**
 * range(2, 6)        // [2,3,4,5,6]
 * range(5).to(8)     // [5,6,7,8]
 * range(4).until(10) // [4,5,6,7,8,9]
 */

var range = function(s, e) {
  if (e == null) {
    return {
      to: function(e) {
        return range(s, e);
      }
    , until: function(e) {
        return range(s, e >= s ? e-1 : e+1);
      }
    }
  }
  var arr = [];
  var ispos = e >= s;
  for (; ispos ? s <= e : e <= s; ispos ? s++ : s--) {
    arr.push(s);
  }
  return arr;
};