-- 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/>.
--
class LIBERTY_CAST_EXPRESSION
   --
   -- Used internally to force the expression type, either via conformance or conversion.
   --

inherit
   LIBERTY_EXPRESSION

create {LIBERTY_CALL_PROMOTION, LIBERTY_CAST_EXPRESSION}
   make

feature {ANY}
   expression: LIBERTY_EXPRESSION
   result_type: LIBERTY_TYPE

   specialized_in (a_type: LIBERTY_ACTUAL_TYPE): like Current is
      local
         e: LIBERTY_EXPRESSION
      do
         check result_type.specialized_in(a_type) = result_type end
         e := expression.specialized_in(a_type)
         if e = expression then
            Result := Current
         else
            create Result.make(e, result_type)
         end
      end

   is_valid_type (a_expression: like expression; a_result_type: like result_type): BOOLEAN is
      require
         a_expression /= Void
         a_result_type /= Void
         {LIBERTY_ACTUAL_TYPE} ?:= a_result_type.known_type
      local
         actual_type: LIBERTY_ACTUAL_TYPE
      do
         actual_type ::= a_result_type.known_type
         Result := a_expression.result_type.known_type.is_conform_to(actual_type)
            or else a_expression.result_type.known_type.converts_to(actual_type)
      end

   accept (v: VISITOR) is
      local
         v0: LIBERTY_CAST_EXPRESSION_VISITOR
      do
         v0 ::= v
         v0.visit_liberty_cast_expression(Current)
      end

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

feature {}
   make (a_expression: like expression; a_result_type: like result_type) is
      require
         a_expression /= Void
         a_result_type /= Void
         is_valid_type(a_expression, a_result_type)
      do
         expression := a_expression
         result_type := a_result_type
         position := a_expression.position
      ensure
         expression = a_expression
         result_type = a_result_type
         position = a_expression.position
      end

invariant
   is_valid_type(expression, result_type)

end