LibTest/collection/ListBase/listbase.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 ListBase<E> class
/// Implements ListMixin<E>
/// Abstract implementation of a list.
/// All operations are defined in terms of length, operator[], operator[]= and
/// length=, which need to be implemented.
/// @description Implementation of length, operator[], operator[]= and length=
/// @author sgrekhov@unipro.ru

library list_base_lib;
import "dart:collection";

class ListBaseImpl<E> extends ListBase<E> {
  List<E> _list;
  
  ListBaseImpl([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 ListBaseImpl(length);
}