tests/base_var_type_evolution_nullable.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Licensed under the Apache License, Version 2.0 (the "License");
   4 # you may not use this file except in compliance with the License.
   5 # You may obtain a copy of the License at
   6 #
   7 #     http://www.apache.org/licenses/LICENSE-2.0
   8 #
   9 # Unless required by applicable law or agreed to in writing, software
  10 # distributed under the License is distributed on an "AS IS" BASIS,
  11 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 # See the License for the specific language governing permissions and
  13 # limitations under the License.
  14
  15 import end
  16 interface Object
  17         fun ==(o: nullable Object): Bool do return self.is_same_instance(o)
  18         fun !=(o: nullable Object): Bool do return not self == o
  19         fun is_same_instance(o: nullable Object): Bool is intern
  20 end
  21 class A
  22 end
  23 class Bool
  24         fun output is intern
  25         redef fun ==(o: nullable Object): Bool is intern
  26         redef fun !=(o: nullable Object): Bool is intern
  27 end
  28
  29 fun test(a: nullable A)
  30 do
  31         __debug__ type nullable A : a
  32
  33         if a isa A then
  34                 __debug__ type A : a
  35         end
  36
  37         __debug__ type nullable A : a
  38
  39         if not a isa A then
  40                 false.output
  41                 return
  42         end
  43
  44         __debug__ type A : a
  45
  46         true.output
  47 end
  48
  49 test(new A)
  50 test(null)