Array.list = (function(hasOwnProperty, toString) {
  return function(obj, varName, expression, optFilter) {
    expression = new Function(varName, 'return ' + expression);
    if (optFilter) {
      optFilter = new Function(varName, 'return ' + optFilter);
    }
    var ret = [];
    function process(key, obj) {
      var value = obj[key];
      if (!optFilter || optFilter.call(obj, value)) {
        ret.push(expression.call(obj, value));
      }
    }
    if (toString.call(obj) == '[object Array]') {
      for (var i = 0, len = obj.length; i < len; i++) {
        process(i, obj);
      }
    }
    else {
      for (var key in obj) {
        if (hasOwnProperty.call(obj, key)) {
          process(key, obj);
        }
      }
    }
    return ret;
  };
})({}.hasOwnProperty, {}.toString);
// Array.list([1,2,3,4,5], 'x', 'x*x');
// Array.list({a:'A', b:'B', c:'C'}, 'c', 'c');
// Array.list([1,2,3,4,5], 'i', 'String.fromCharCode(64+i)', 'i%2');