int visitorWay() {
CharStream stream = new ANTLRInputStream(EXPRESSION);
CalculatorLexer lexer = new CalculatorLexer(stream);
CommonTokenStream tokenStream = new CommonTokenStream(lexer);
CalculatorParser parser = new CalculatorParser(tokenStream);
// System.out.println(parser.c());
ParseTree tree = parser.c();
CalculatorBaseVisitor<Integer> visitor = new CalculatorEvaluationVisitor();
Integer sum = visitor.visit(tree);
return sum;
}
int listenerWay() {
CharStream stream = new ANTLRInputStream(EXPRESSION);
CalculatorLexer lexer = new CalculatorLexer(stream);
CommonTokenStream tokenStream = new CommonTokenStream(lexer);
CalculatorParser parser = new CalculatorParser(tokenStream);
// System.out.println(parser.c());
ParseTree tree = parser.c();
ParseTreeWalker walker = new ParseTreeWalker();
CalculatorWalker calcWalker = new CalculatorWalker();
walker.walk(calcWalker, tree);
return calcWalker.getSum();
}