dir_constant.e

   1 deferred class DIR_CONSTANT
   2 feature
   3     dir_up : INTEGER is 1
   4     dir_right : INTEGER is 2
   5     dir_down : INTEGER is 3
   6     dir_left : INTEGER is 4
   7
   8     dir_opposite(dir : INTEGER) : INTEGER is
   9     do
  10         inspect dir
  11         when dir_up then
  12             Result := dir_down
  13         when dir_down then
  14             Result := dir_up
  15         when dir_left then
  16             Result := dir_right
  17         when dir_right then
  18             Result := dir_left
  19         end
  20     end
  21 end