| /* |
| * Copyright (c) 2011, 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 logical boolean expression b of the form e1 && e2 shows that a |
| * variable v has type T if all of the following conditions hold: |
| * • Either e1 shows that v has type T or e2 shows that v has type T. |
| * • v is a local variable or formal parameter. |
| * • The variable v is not mutated in e2 or within a closure. |
| * Furthermore, if all of the following hold: |
| * • e1 shows that v has type T. |
| * • v is not mutated in either e1 , e2 or within a closure. |
| * • If the variable v is accessed by a closure in e2 then the variable v is not |
| * potentially mutated anywhere in the scope of v. |
| * then the type of v is known to be T in e2. |
| * @description Checks that if v is local variable or formal parameter, either |
| * e1 or e2 shows that v has type T, v is not mutated in e2 or in a closure, |
| * then b shows that v has type T even if v is mutated in e1. |
| * @author ilya |
| */ |
| |
| class C {} |
| |
| class D extends C { |
| f() {} |
| } |
| |
| skyIsBlue(_) => true; |
| |
| f1(C x) { |
| skyIsBlue(x = new D()) && (x is D && skyIsBlue((() => x)())) ? x.f() : null; |
| } |
| |
| f2(C y) { |
| C x = y; |
| |
| skyIsBlue(x = new D()) && (x is D && skyIsBlue((() => x)())) ? x.f() : null; |
| } |
| |
| main() { |
| f1(new D()); |
| f2(new D()); |
| } |