type.js

/**
 * toString ref.
 * @private
 */

var toString = Object.prototype.toString;

/**
 * Return the type of `val`.
 * @private
 * @param {Mixed} val
 * @return {String}
 * @api public
 */

export default function(val) {
  switch (toString.call(val)) {
    case '[object Date]': return 'date';
    case '[object RegExp]': return 'regexp';
    case '[object Arguments]': return 'arguments';
    case '[object Array]': return 'array';
    case '[object Error]': return 'error';
  }

  if (val === null) {
    return 'null';
  }
  if (val === undefined) {
    return 'undefined';
  }
  if (val !== val) {
    return 'nan';
  }
  if (val && val.nodeType === 1) {
    return 'element';
  }

  if (typeof Buffer !== 'undefined' && typeof Buffer.isBuffer === 'function' && Buffer.isBuffer(val)) {
    return 'buffer';
  }

  val = val.valueOf ? val.valueOf() : Object.prototype.valueOf.apply(val);
  return typeof val;
}