| // 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 and v is not mutated anywhere in its scope |
| /// then b shows that v has type T regardless of whether there are closures |
| /// capturing v. Local variable, closures case. |
| /// @author ilya |
| |
| |
| class C {} |
| class D extends C { |
| f() {} |
| } |
| class E extends D { |
| g() {} |
| } |
| |
| skyIsBlue(_) => true; |
| |
| f(C y) { |
| C x = y; |
| |
| x is D && skyIsBlue((() => x) ()) ? x.f() : null; |
| skyIsBlue((() => x) ()) && x is D ? x.f() : null; |
| |
| (x is D && skyIsBlue((() => x) ())) |
| && (x is E && skyIsBlue((() => x) ())) ? x.g() : null; |
| |
| (skyIsBlue((() => x) ()) && x is E) |
| && (skyIsBlue((() => x) ()) && x is D) ? x.g() : null; |
| } |
| |
| main() { |
| f(new D()); |
| f(new E()); |
| } |