-- This file is part of Liberty Eiffel.
--
-- Liberty Eiffel is free software: you can redistribute it and/or modify
-- it under the terms of the GNU General Public License as published by
-- the Free Software Foundation, version 3 of the License.
--
-- Liberty Eiffel is distributed in the hope that it will be useful,
-- but WITHOUT ANY WARRANTY; without even the implied warranty of
-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-- GNU General Public License for more details.
--
-- You should have received a copy of the GNU General Public License
-- along with Liberty Eiffel.  If not, see <http://www.gnu.org/licenses/>.
--
deferred class LIBERTY_COMPARISON

inherit
   LIBERTY_EXPRESSION

feature {ANY}
   left, right: LIBERTY_EXPRESSION
   result_type: LIBERTY_TYPE

   specialized_in (a_type: LIBERTY_ACTUAL_TYPE): like Current is
      local
         l, r: LIBERTY_EXPRESSION
      do
         check result_type.specialized_in(a_type) = result_type end
         l := left.specialized_in(a_type)
         r := right.specialized_in(a_type)
         if l = left and then r = right then
            Result := Current
         else
            Result := make_new(l, r, result_type, position)
         end
      end

feature {LIBERTY_REACHABLE, LIBERTY_REACHABLE_COLLECTION_MARKER}
   mark_reachable_code (mark: INTEGER) is
      do
         left.mark_reachable_code(mark)
         right.mark_reachable_code(mark)
      end

feature {}
   make_new (a_left: like left; a_right: like right; a_result_type: like result_type; a_position: like position): like Current is
      require
         a_left /= Void
         a_right /= Void
         a_result_type /= Void
         -- a_result_type is BOOLEAN
         a_position /= Void
      deferred
      ensure
         Result.left = a_left
         Result.right = a_right
         Result.result_type = a_result_type
         Result.position = a_position
      end

   make (a_left: like left; a_right: like right; a_result_type: like result_type; a_position: like position) is
      require
         a_left /= Void
         a_right /= Void
         a_result_type /= Void
         -- a_result_type is BOOLEAN
         a_position /= Void
      do
         left := a_left
         right := a_right
         result_type := a_result_type
         position := a_position
      ensure
         left = a_left
         right = a_right
         result_type = a_result_type
         position = a_position
      end

invariant
   left /= Void
   right /= Void

end