LanguageFeatures/Extension-methods/syntax_name_t01.dart

// Copyright (c) 2019, 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.

/**
 * @assertion an extension declaration is a top-level declaration with a grammar
 * similar to:
 * <extension> ::=
 *   `extension' <identifier>? <typeParameters>? `on' <type> `?'? `{'
 *     memberDeclaration*
 *   `}'
 * Such a declaration introduces its name (the identifier) into the surrounding
 * scope. The name does not denote a type, but it can be used to denote the
 * extension itself in various places. The name can be hidden or shown in import
 * or export declarations.
 *
 * @description Check that the name does not denote a type
 * @compile-error
 * @author sgrekhov@unipro.ru
 */


extension MyFancyList<T> on List<T> {
  int get doubleLength => this.length * 2;
  List<T> operator-() => this.reversed.toList();
  List<List<T>> split(int at) => <List<T>>[this.sublist(0, at), this.sublist(at)];
  static String get className => "List";
}

main() {
  MyFancyList<String> list = ["Lily", "was", "here"];
}