package org.apidesign.test.visitor;

import static junit.framework.Assert.*;

import org.apidesign.visitor.Language.Expression;

import org.apidesign.visitor.Language.Number;

import org.apidesign.visitor.Language.Plus;

import org.apidesign.visitor.Language.Visitor1_0;

import org.junit.Test;

public class PrintTest {

    public static class PrintVisitor implements Visitor1_0 {

        StringBuffer sb = new StringBuffer();

        public void visitUnknown(Expression exp) {

            sb.append("unknown");

        }

        public void visitPlus(Plus s) {

            s.getFirst().visit(this);

            sb.append(" + ");

            s.getSecond().visit(this);

        }

        public void visitNumber(Number n) {

            sb.append (n.getValue());

        }

    }

    @Test public void printOnePlusOne() {

        Number one = new Number(1);

        Expression plus = new Plus(one, one);

        PrintVisitor print = new PrintVisitor();

        plus.visit(print);

        assertEquals("1 + 1", print.sb.toString());

    }

    @Test public void printOnePlusTwoPlusThree() {

        Number one = new Number(1);

        Number two = new Number(2);

        Number three = new Number(3);

        Expression plus = new Plus(one, new Plus(two, three));

        PrintVisitor print = new PrintVisitor();

        plus.visit(print);

        assertEquals("1 + 2 + 3", print.sb.toString());

    }

}