// This may look like C code, but it is really -*- C++ -*- // ------------------------------------------------------------------ // The Goldware Library // Copyright (C) 1990-1999 Odinn Sorensen // ------------------------------------------------------------------ // This library 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. // // This library 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 program; if not, write to the Free // Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, // MA 02111-1307, USA // ------------------------------------------------------------------ // $Id$ // ------------------------------------------------------------------ // Expression evaluator base class. // ------------------------------------------------------------------ #include <gdefs.h> #include <geval.h> // ------------------------------------------------------------------ geval::geval() { // nothing to do } // ------------------------------------------------------------------ geval::~geval() { // nothing } // ------------------------------------------------------------------ geval::ops geval::pop_operator() { ops o = ostk.back(); ostk.pop_back(); return o; } // ------------------------------------------------------------------ int geval::pop_value() { int v = vstk.back(); vstk.pop_back(); return v; } // ------------------------------------------------------------------ void geval::push_value(int v) { vstk.push_back(v); } // ------------------------------------------------------------------ void geval::push_operator(geval::ops o) { ostk.push_back(o); } // ------------------------------------------------------------------ int geval::evaluate_op(geval::ops o, int y, int x) { switch(o) { case addition: return y + x; case subtraction: return y - x; case multiplication: return y * x; case division: return y / x; case modulus: return y % x; case negation: return -x; case logic_not: return (not x) ? 1 : 0; case logic_and: return (y and x) ? 1 : 0; case logic_xor: return (y ^ x) ? 1 : 0; case equal: return (y == x) ? 1 : 0; case not_equal: return (y != x) ? 1 : 0; case greater: return (y > x) ? 1 : 0; case greater_or_equal: return (y >= x) ? 1 : 0; case lesser: return (y < x) ? 1 : 0; case lesser_or_equal: return (y <= x) ? 1 : 0; default: ; } return 0; } // ------------------------------------------------------------------