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/*
   Copyright (C) 2019-2020 Andreas Franz Borchert
                           Michael Christian Lehn
   ----------------------------------------------------------------------------
   The Astl Library for ULMasm is free software; you can redistribute it
   and/or modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either version
   2 of the License, or (at your option) any later version.

   The Astl Library for ULMasm 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
   Library General Public License for more details.

   You should have received a copy of the GNU Library General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

attribution rules {

    // leaf nodes have an immediate value
    ("integer" int) as node -> post {
        node.value = int;
    }

    // evaluate sub nodes
    ("+" op1 op2) as node -> post {
        node.value = op1.value + op2.value;
    }
    ("-" op1 op2) as node -> post {
        node.value = op1.value - op2.value;
    }

    // expression now has result
    ("expression" expr) as node -> post {
        println(expr.value);
    }
}