const uniq = (array, iterator) => {
  if (iterator) return [...(new Map(array.map(x => [iterator(x), x]))).values()]
  else return [...new Set(array)]
}

const objectToString = o => Object.prototype.toString.call(o)

const isObject = arg => typeof arg === 'object' && arg !== null

const isDate = d => isObject(d) && objectToString(d) === '[object Date]'

const isRegExp = re => isObject(re) && objectToString(re) === '[object RegExp]'

module.exports.uniq = uniq
module.exports.isDate = isDate
module.exports.isRegExp = isRegExp