var _curry2 = require('./internal/_curry2');


/**
 * Creates a new list out of the two supplied by creating each possible pair
 * from the lists.
 *
 * @func
 * @memberOf R
 * @since v0.1.0
 * @category List
 * @sig [a] -> [b] -> [[a,b]]
 * @param {Array} as The first list.
 * @param {Array} bs The second list.
 * @return {Array} The list made by combining each possible pair from
 *         `as` and `bs` into pairs (`[a, b]`).
 * @example
 *
 *      R.xprod([1, 2], ['a', 'b']); //=> [[1, 'a'], [1, 'b'], [2, 'a'], [2, 'b']]
 * @symb R.xprod([a, b], [c, d]) = [[a, c], [a, d], [b, c], [b, d]]
 */
module.exports = _curry2(function xprod(a, b) { // = xprodWith(prepend); (takes about 3 times as long...)
  var idx = 0;
  var ilen = a.length;
  var j;
  var jlen = b.length;
  var result = [];
  while (idx < ilen) {
    j = 0;
    while (j < jlen) {
      result[result.length] = [a[idx], b[j]];
      j += 1;
    }
    idx += 1;
  }
  return result;
});