-- 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_AST_EXPRESSION_BINARY[E_ -> LIBERTY_AST_NON_TERMINAL_NODE]

inherit
   LIBERTY_AST_NON_TERMINAL_NODE

feature {LIBERTY_AST_HANDLER}
   left_expression: E_ is
      require
         not is_empty
         not is_binary
      do
         Result ::= nodes.first
      end

   left_binary: like Current is
      require
         not is_empty
         is_binary
      do
         Result ::= nodes.first
      end

   right_expression: E_ is
      require
         not is_empty
      do
         Result ::= nodes.last
      end

   is_binary: BOOLEAN is
      require
         not is_empty
      do
         Result := nodes.first.name = eiffel_name
      end

   is_double_operator: BOOLEAN is
      do
         Result := count = 4
      end

   operator1: EIFFEL_IMAGE is
      local
         op1: LIBERTY_AST_TERMINAL_NODE
      do
         op1 ::= nodes.item(1)
         Result := op1.image
      end

   operator2: EIFFEL_IMAGE is
      require
         is_double_operator
      local
         op2: LIBERTY_AST_TERMINAL_NODE
      do
         op2 ::= nodes.item(2)
         Result := op2.image
      end

feature {ANY}
   count: INTEGER is
      do
         Result := nodes.count
      end

feature {}
   possible_counts: SET[INTEGER] is
      once
         Result := {AVL_SET[INTEGER] << 3, 4 >> } -- depends on the operator
      end

   errors: LIBERTY_ERRORS

end