| // 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 conditional expression c of the form e1 ? e2 : e3. |
| /// If all of the following hold: |
| /// • e1 shows that a variable v has type T. |
| /// • v is not potentially mutated in 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 e1 shows that v has type T and v is not |
| /// potentially mutated anywhere in the scope of v, then the type of v is |
| /// known to be T in e2, regardless of whether there are closures capturing v. |
| /// No closures case. |
| /// @author ilya |
| |
| |
| class C {} |
| class D extends C { |
| f() {} |
| } |
| |
| // formal parameter |
| f1(C x) { |
| x is D ? x.f() : null; |
| } |
| |
| // local variable |
| f2(C y) { |
| C x = y; |
| x is D ? x.f() : null; |
| } |
| |
| main() { |
| f1(new D()); |
| f2(new D()); |
| } |