package org.apidesign.test.visitor;

 import org.apidesign.test.visitor.PrintTest.PrintVisitor;

 import static junit.framework.Assert.*;

 import org.apidesign.visitor.Language.Expression;

 import org.apidesign.visitor.Language.Minus;

 import org.apidesign.visitor.Language.Number;

 import org.apidesign.visitor.Language.Plus;

 import org.apidesign.visitor.Language.Real;

 import org.apidesign.visitor.Language.Visitor3_0;

 import org.junit.Test;

 public class PrintOfMinusStructureTest {

     @Test public void printOneMinusTwo() {

         Real one = new Real(1);

         Real two = new Real(2);

         Expression plus = new Minus(one, two);

         PrintVisitor print = new PrintVisitor();

         plus.visit(print);

         if (Boolean.getBoolean("no.failures")) {

             assertEquals(

                 "Not defined how to handle Minus. We'll get wrong result",

                 "unknown", print.sb.toString()

             );

             return;

         }

         assertEquals("1.0 - 2.0", print.sb.toString());

     }

     @Test public void visitorReadyForVersion3_0() {

         // BEGIN: visitor.nonmonotonic.print3

         class PrintVisitor3_0 implements Visitor3_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());

             }

             public void visitMinus(Minus m) {

                 m.getFirst().visit(this);

                 sb.append(" - ");

                 m.getSecond().visit(this);

             }

             public void visitReal(Real r) {

                 sb.append(r.getValue());

             }

         }

         Number one = new Number(1);

         Number two = new Number(2);

         Expression plus = new Minus(one, two);

         PrintVisitor3_0 print = new PrintVisitor3_0();

         plus.visit(print);

         assertEquals("1.0 - 2.0", print.sb.toString());

         // END: visitor.nonmonotonic.print3

         Real five = new Real(5);

         Real three = new Real(3);

         Expression realPlus = new Minus(five, three);

         PrintVisitor3_0 printReal = new PrintVisitor3_0();

         realPlus.visit(printReal);

         assertEquals("5.0 - 3.0", printReal.sb.toString());

     }

 }