/**
  * 序号列表生成函数
  *
  * @param {Number} start 起始值
  * @param {Number} stop 结束值
  * @param {Number} step 自增值
  * @return {Object}
  */
function range (start, stop, step) {
  var index, len
  var result = []
  var args = arguments
  if (args.length < 2) {
    stop = args[0]
    start = 0
  }
  index = start >> 0
  len = stop >> 0
  if (index < stop) {
    step = step >> 0 || 1
    for (; index < len; index += step) {
      result.push(index)
    }
  }
  return result
}

module.exports = range