tests/base_var_type_evolution_null3.nit

   1 # This file is part of NIT ( http://www.nitlanguage.org ).
   2 #
   3 # Copyright 2010 Jean Privat <jean@pryen.org>
   4 #
   5 # Licensed under the Apache License, Version 2.0 (the "License");
   6 # you may not use this file except in compliance with the License.
   7 # You may obtain a copy of the License at
   8 #
   9 #     http://www.apache.org/licenses/LICENSE-2.0
  10 #
  11 # Unless required by applicable law or agreed to in writing, software
  12 # distributed under the License is distributed on an "AS IS" BASIS,
  13 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14 # See the License for the specific language governing permissions and
  15 # limitations under the License.
  16
  17 import kernel
  18
  19 class G[A: nullable Object]
  20         var _a: A
  21         init (a: A) do _a = a
  22
  23         fun run
  24         do
  25                 var a = _a
  26
  27                 if a != null then
  28                         a.output
  29                 end
  30
  31                 _a = a
  32         end
  33
  34         fun na: nullable A = _a
  35
  36         fun run2
  37         do
  38                 var na = na
  39                 if na != null then
  40                         na.output
  41                         _a = na
  42                 end
  43
  44                 #alt1# _a = na
  45         end
  46 end
  47
  48 fun foo
  49 do
  50         var a: Object = 5
  51         var o = a
  52         if a != null then
  53                 a.output
  54         end
  55         o = a
  56 end
  57
  58 fun rand: Bool do return true
  59
  60 var g = new G[Object](1)
  61 g.run
  62 g.run2
  63 foo