Cartesian Product in JavaScript

function cartProd() {
  var args = [].slice.call(arguments)
    , end  = args.length - 1

  var result = []

  function addTo(curr, start) {
    var first = args[start]
      , last  = (start === end)

    for (var i = 0; i < first.length; ++i) {
      var copy = curr.slice()
      copy.push(first[i])

      if (last) {
        result.push(copy)
      } else {
        addTo(copy, start + 1)
      }
    }
  }

  if (args.length) {
    addTo([], 0)
  } else {
    result.push([])
  }
  return result
}