Language/Types/Type_Aliases/syntax_t20.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 A type alias declares a name for a type expression.
 * <typeAlias> ::=<metadata> typedef <typeIdentifier> <typeParameters>?‘=’<type>
 * ‘;’
 * | <metadata> typedef <functionTypeAlias>
 *  <functionTypeAlias> ::= <functionPrefix> <formalParameterPart> ‘;’
 *  <functionPrefix> ::= <type>? <identifier>
 * @description Checks that type alias syntax works as expected. Test
 * built-in types
 * @author sgrekhov@unipro.ru
 */
// SharedOptions=--enable-experiment=nonfunction-type-aliases

import "../../../Utils/expect.dart";

const int meta = 1;

void getVoid() {}
dynamic getDynamic() => "123";

@meta typedef Aint = int;
@meta typedef Anum = num;
@meta typedef Adouble = double;
@meta typedef AString = String;
@meta typedef AObject = Object;
@meta typedef Avoid = void;
@meta typedef ANull = Null;
@meta typedef Adynamic = dynamic;
@meta typedef AFunction = Function;

main() {
  Aint ai = 1;
  Expect.isTrue(ai is int);
  Expect.isTrue(1 is Aint);

  Anum an = 3;
  an = 3.14;
  Expect.isTrue(an is num);

  Adouble ad = 3.1415926;
  Expect.isTrue(ad is double);

  AString as = new AString("Lily was here");
  Expect.isTrue(as is String);

  AObject ao = new AObject();
  ao = new Object();

  Avoid av = getVoid();

  ANull anull = null;
  Expect.isTrue(anull is Null);

  Adynamic adyn = getDynamic();
  Expect.isTrue(adyn is dynamic);

  AFunction af = getVoid;
  Expect.isTrue(af is Function);
}