LibTest/collection/ListMixin/listmixin_lib.dart

// Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

// @dart = 2.9

/// @assertion ListMixin<E> abstract class 
/// Implements List<E>
/// Base implementation of a List class.
/// ListMixin can be used as a mixin to make a class implement the List interface.
/// This implements all read operations using only the length and operator[]
/// members. It implements write operations using those and length= and
/// operator[]=
/// @description Implementation of operator[]= and length=
/// @author sgrekhov@unipro.ru

library list_mixin_lib;
import "dart:collection";

class MyList<E> extends Object with ListMixin<E> {
  List<E> _list;
  
  MyList([int length]): _list = (length == null ? new List() : new List(length));
  
  E operator [](int index) => _list[index];

  void operator []=(int index, E value) {
    _list[index] = value;
  }

  int get length => _list.length;

  void set length(int newLength) {
    _list.length = newLength;
  }
}
 
List create([int length]) {
  return new MyList(length);
}