var _containsWith = require('./internal/_containsWith');
var _curry3 = require('./internal/_curry3');
var _filter = require('./internal/_filter');


/**
 * Takes a predicate `pred`, a list `xs`, and a list `ys`, and returns a list
 * `xs'` comprising each of the elements of `xs` which is equal to one or more
 * elements of `ys` according to `pred`.
 *
 * `pred` must be a binary function expecting an element from each list.
 *
 * `xs`, `ys`, and `xs'` are treated as sets, semantically, so ordering should
 * not be significant, but since `xs'` is ordered the implementation guarantees
 * that its values are in the same order as they appear in `xs`. Duplicates are
 * not removed, so `xs'` may contain duplicates if `xs` contains duplicates.
 *
 * @func
 * @memberOf R
 * @since v0.24.0
 * @category Relation
 * @sig (a -> b -> Boolean) -> [a] -> [b] -> [a]
 * @param {Function} pred
 * @param {Array} xs
 * @param {Array} ys
 * @return {Array}
 * @see R.intersection
 * @example
 *
 *      R.innerJoin(
 *        (record, id) => record.id === id,
 *        [{id: 824, name: 'Richie Furay'},
 *         {id: 956, name: 'Dewey Martin'},
 *         {id: 313, name: 'Bruce Palmer'},
 *         {id: 456, name: 'Stephen Stills'},
 *         {id: 177, name: 'Neil Young'}],
 *        [177, 456, 999]
 *      );
 *      //=> [{id: 456, name: 'Stephen Stills'}, {id: 177, name: 'Neil Young'}]
 */
module.exports = _curry3(function innerJoin(pred, xs, ys) {
  return _filter(function(x) { return _containsWith(pred, x, ys); }, xs);
});