cycle.js

cycle.js

var cycle = function() {
  var i = 1;
  return function(first, second) {
    if (first === 'reset') {
      i = 1;
      return;
    }
    var value = [first, second][i = 1 - i];
    return value;
  };
}();



cycle('odd', 'even'); //# =>  odd
cycle('odd', 'even'); //# =>  even
cycle('odd', 'even'); //# =>  odd
cycle('reset');
cycle('odd', 'even'); //# =>  odd
cycle('odd', 'even'); //# =>  even
cycle('odd', 'even'); //# =>  odd
cycle('odd', 'even'); //# =>  even