| // TODO(multitest): This was automatically migrated from a multitest and may |
| // contain strange or dead code. |
| |
| // Copyright (c) 2013, 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. |
| |
| // Test least upper bound through type checking of conditionals. |
| |
| class N<T> { |
| T get n => null; |
| } |
| |
| class C1<T> extends N<N<C1<T>>> { |
| T get c1 => null; |
| } |
| |
| class C2<T> extends N<N<C2<N<C2<T>>>>> { |
| T get c2 => null; |
| } |
| |
| /** |
| * Test that we don't try to find the least upper bound by applying the |
| * algorithm for finding the most specific common declaration recursively on |
| * type arguments. |
| * |
| * For C1<int> and N<C1<String>> this would result in this infinite chain of |
| * computations: |
| * |
| * lub(C1<int>, N<C1<String>>) = lub(N<N<C1<int>>>, N<C1<String>>) |
| * => |
| * lub(N<C1<int>>, C1<String>) = lub(N<C1<int>>, N<N<C1<String>>>) |
| * => |
| * lub(C1<int>, N<C1<String>>) = lub(N<N<C1<int>>>, N<C1<String>>>) |
| * => ... |
| */ |
| void testC1(bool z, C1<int> a, N<C1<String>> b) { |
| if (z) { |
| // The least upper bound of C1<int> and N<C1<String>> is Object since the |
| // supertypes are |
| // {C1<int>, N<N<C1<int>>>, Object} for C1<int> and |
| // {N<C1<String>>, Object} for N<C1<String>> and |
| // Object is the most specific type in the intersection of the supertypes. |
| |
| // Is least upper bound dynamic? |
| |
| // Is least upper bound N<...> ? |
| |
| // Is least upper bound C1<...> ? |
| |
| // Is least upper bound N<dynamic> ? |
| |
| // Is least upper bound N<N<...>> ? |
| |
| // Is least upper bound N<C1<...>> ? |
| |
| } |
| } |
| |
| /** |
| * Test that we don't try to find the least upper bound by applying the |
| * algorithm for finding the most specific common declaration recursively on |
| * type arguments. |
| * |
| * For C1<int> and N<C1<String>> this would result in this infinite and |
| * expanding chain of computations: |
| * |
| * lub(C2<int>, N<C2<String>>) = lub(N<N<C2<N<C2<int>>>>>, N<C2<String>>) |
| * => |
| * lub(N<C2<N<C2<int>>>>, C2<String>) = |
| * lub(N<C2<N<C2<int>>>>, N<N<C2<N<C2<String>>>>>) |
| * => |
| * lub(C2<N<C2<int>>>, N<C2<N<C2<String>>>>) = |
| * lub(N<N<C2<N<C2<int>>>>>, N<C2<N<C2<String>>>>>) |
| * => ... |
| */ |
| |
| void testC2(bool z, C2<int> a, N<C2<String>> b) { |
| if (z) { |
| // The least upper bound of C2<int> and N<C2<String>> is Object since the |
| // supertypes are |
| // {C2<int>, N<N<C2<N<C2<int>>>>>, Object} for C1<int> and |
| // {N<C2<String>>, Object} for N<C1<String>> and |
| // Object is the most specific type in the intersection of the supertypes. |
| |
| // Is least upper bound dynamic? |
| |
| // Is least upper bound N<...> ? |
| |
| // Is least upper bound C2<...> ? |
| |
| // Is least upper bound N<dynamic> ? |
| |
| // Is least upper bound N<N<...>> ? |
| |
| // Is least upper bound N<C2<...>> ? |
| |
| } |
| } |
| |
| void main() { |
| testC1(false, null, null); |
| testC2(false, null, null); |
| } |