with opal

exercise_one.js

(function($opal) {
  var self = $opal.top, $scope = $opal, nil = $opal.nil, $breaker = $opal.breaker, $slice = $opal.slice, $hash2 = $opal.hash2;
  $opal.add_stubs(['$send', '$&', '$collect', '$[]', '$keys', '$empty?', '$each', '$compact', '$flatten', '$==', '$first']);
  return ($opal.Object._proto.$preferred_code = function(preferred_code_sets, codes_attribute, value_set_map) {try {

    var $a, $b, TMP_1, $c, TMP_2, self = this, codes_value = nil, matching_code_sets = nil, code_set = nil;
    if (codes_attribute == null) {
      codes_attribute = "codes"
    }
    if (value_set_map == null) {
      value_set_map = nil
    }
    codes_value = self.$send(codes_attribute);
    preferred_code_sets = (function() {if (value_set_map !== false && value_set_map !== nil) {
      return (preferred_code_sets['$&'](($a = ($b = value_set_map).$collect, $a._p = (TMP_1 = function(cs){var self = TMP_1._s || this;if (cs == null) cs = nil;
      return cs['$[]']("set")}, TMP_1._s = self, TMP_1), $a).call($b)))
      } else {
      return preferred_code_sets
    }; return nil; })();
    matching_code_sets = preferred_code_sets['$&'](codes_value.$keys());
    if (($a = matching_code_sets['$empty?']()) !== false && $a !== nil) {
      return nil
    } else if (value_set_map !== false && value_set_map !== nil) {
      return ($a = ($c = matching_code_sets).$each, $a._p = (TMP_2 = function(matching_code_set){var self = TMP_2._s || this, $a, $b, TMP_3, $c, matching_codes = nil;if (matching_code_set == null) matching_code_set = nil;
      matching_codes = codes_value['$[]'](matching_code_set)['$&'](($a = ($b = value_set_map).$collect, $a._p = (TMP_3 = function(cs){var self = TMP_3._s || this;if (cs == null) cs = nil;
        if (cs['$[]']("set")['$=='](matching_code_set)) {
            return cs['$[]']("values")
            } else {
            return []
          }}, TMP_3._s = self, TMP_3), $a).call($b).$flatten().$compact());
        if (($a = ($c = matching_codes['$empty?'](), ($c === nil || $c === false))) !== false && $a !== nil) {
          $opal.$return($hash2(["code", "code_set"], {"code": matching_codes.$first(), "code_set": matching_code_set}))
          } else {
          return nil
        };}, TMP_2._s = self, TMP_2), $a).call($c)
      } else {
      code_set = matching_code_sets.$first();
      return $hash2(["code", "code_set"], {"code": codes_value['$[]'](code_set).$first(), "code_set": code_set});
    };
    } catch ($returner) { if ($returner === $opal.returner) { return $returner.$v } throw $returner; }
  }, nil)
})(Opal);