// $Id: exprcalc.cc 59 2007-07-17 14:43:23Z tb $ /* * STX Expression Parser C++ Framework v0.7 * Copyright (C) 2007 Timo Bingmann * * This library is free software; you can redistribute it and/or modify it * under the terms of the GNU Lesser General Public License as published by the * Free Software Foundation; either version 2.1 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 Lesser General Public License * for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library; if not, write to the Free Software Foundation, * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** \file exprcalc.cc * File containing the first example application: * A Simple Expression Calculator. * See the doxygen documentation for a detailed walk-through of the code. */ // Simple Expression Calculator Example #include <iostream> #include "ExpressionParser.h" int main(int argc, char *argv[]) { // collect expression by joining all input arguments std::string args; for(int i = 1; i < argc; i++) { if (!args.empty()) args += " "; args += argv[i]; } std::cout << "input string: " << args << "\n"; // parse expression into a parse tree stx::ParseTree pt; try { pt = stx::parseExpression(args); std::cout << "parsed: " << pt.toString() << "\n"; } catch (stx::ExpressionParserException &e) { std::cout << "ExpressionParserException: " << e.what() << "\n"; return 0; } // evaluate the expression with a very simple symbol table stx::BasicSymbolTable bst; bst.setVariable("x", 42); try { stx::AnyScalar val = pt.evaluate(bst); std::cout << "evaluated: " << val << "\n"; } catch (stx::UnknownSymbolException &e) { std::cout << "UnknownSymbolException: " << e.what() << "\n"; return 0; } catch (stx::ExpressionParserException &e) { std::cout << "ExpressionParserException: " << e.what() << "\n"; return 0; } return 0; }