tests/base_var_type_evolution_null_while.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
  17 interface Object
  18         fun ==(o: nullable Object): Bool do return self.is_same_instance(o)
  19         fun !=(o: nullable Object): Bool do return not self.is_same_instance(o)
  20         fun is_same_instance(other: nullable Object): Bool is intern
  21 end
  22 class A
  23 end
  24
  25 class Bool
  26         fun output is intern
  27 end
  28
  29 fun maybe: Bool do return true
  30
  31 fun test1(a: nullable A)
  32 do
  33         var res = a
  34         while res == null do
  35                 if maybe then
  36                         false.output
  37                         return
  38                 end
  39         end
  40         __debug__ type A : res
  41         true.output
  42 end
  43
  44 fun test2(a: nullable A)
  45 do
  46         var res = a
  47         while res != null do
  48                 __debug__ type A : res
  49                 if maybe then
  50                         false.output
  51                         return
  52                 end
  53         end
  54         true.output
  55 end
  56
  57 test1(new A)
  58 test1(null)
  59 test2(new A)
  60 test2(null)