Iterable

Base trait that can be used to compose traits with non-standard enumeration behaviors.

This trait is supposed to be used as part of a composition, since it only provides custom enumeration behavior to a composed object. It defines one required _keyValueMap property, that is used as a hash of "key-values" to iterate on during enumeration.

List

An ordered collection (also known as a sequence) disallowing duplicate elements. List is composed out of Iterable, therefore it provides custom enumeration behavior that is similar to array (enumerates only on the elements of the list).

List is a base trait and is meant to be part of a composition, since all of its API is private except for the length property.

Examples:

var MyList = List.compose({
  add: function add(item1, item2, /*item3...*/) {
    Array.slice(arguments).forEach(this._add.bind(this));
  },
  remove: function remove(item1, item2, /*item3...*/) {
    Array.slice(arguments).forEach(this._remove.bind(this));
  }
});
MyList('foo', 'bar', 'baz').length == 3;        // true
new MyList('new', 'keyword').length == 2;       // true
MyList.apply(null, [1, 2, 3]).length == 3;      // true
let list = MyList();
list.length == 0;                               // true
list.add(1, 2, 3) == 3;                         // true