jtulach@177: package org.apidesign.visitor;
jtulach@177: 
jtulach@177: public final class Language {
jtulach@177:     private Language() { }
jtulach@177:     
jtulach@177:     public interface Expression {
jtulach@177:         public abstract void visit(Visitor v);
jtulach@177:     }
jtulach@177:     public interface Plus extends Expression {
jtulach@177:         public Expression getFirst();
jtulach@177:         public Expression getSecond();
jtulach@177:     }
jtulach@177:     public interface Number extends Expression {
jtulach@177:         public int getValue();
jtulach@177:     }
jtulach@177:     /** @since 2.0 */
jtulach@177:     public interface Minus extends Expression {
jtulach@177:         public Expression getFirst();
jtulach@177:         public Expression getSecond();
jtulach@177:     }
jtulach@177:     
jtulach@177:     // BEGIN: visitor.clientprovider.v3
jtulach@177:     /** @since 3.0 */
jtulach@177:     public interface Real extends Expression {
jtulach@177:         public double getValue();
jtulach@177:     }
jtulach@177:     public static abstract class Visitor {
jtulach@177:         Visitor() {}
jtulach@177:         
jtulach@177:         
jtulach@177:         /** @since 3.0 */
jtulach@266:         public static Visitor create(Version30 v) {
jtulach@266:             return create30(v);
jtulach@177:         }
jtulach@177: 
jtulach@177:         /** @since 3.0 */
jtulach@266:         public interface Version30 {
jtulach@177:             public boolean visitUnknown(Expression e);
jtulach@177:             public void visitPlus(Plus s);
jtulach@177:             public void visitMinus(Minus s);
jtulach@177:             public void visitReal(Real r);
jtulach@177:         }
jtulach@177: 
jtulach@177:         /** @since 3.0 */
jtulach@177:         public abstract void dispatchReal(Real r);
jtulach@177:         
jtulach@177:     // FINISH: visitor.clientprovider.v3
jtulach@177:         /** @since 2.0 */
jtulach@266:         public static Visitor create(Version20 v) {
jtulach@266:             return create20(v);
jtulach@177:         }
jtulach@177: 
jtulach@177:         /** @since 2.0 */
jtulach@266:         public interface Version20 extends Version10 {
jtulach@177:             public void visitMinus(Minus m);
jtulach@177:         }
jtulach@177: 
jtulach@177: 
jtulach@177:         /** @since 2.0 */
jtulach@177:         public abstract void dispatchNumber(Number n);
jtulach@177:         
jtulach@266:         public static Visitor create(Version10 v) {
jtulach@266:             return create10(v);
jtulach@177:         }
jtulach@177: 
jtulach@266:         public interface Version10 {
jtulach@177:             public boolean visitUnknown(Expression e);
jtulach@177:             public void visitPlus(Plus s);
jtulach@177:             public void visitNumber(Number n);
jtulach@177:         }
jtulach@177: 
jtulach@177:         public abstract void dispatchPlus(Plus p);
jtulach@177:         public abstract void dispatchMinus(Minus m);
jtulach@177:     }
jtulach@177:     
jtulach@177:     // BEGIN: visitor.clientprovider.dispatch.v3.l1
jtulach@266:     static Visitor create10(final Visitor.Version10 v) {
jtulach@177:         return new Visitor() {
jtulach@177:             @Override
jtulach@177:             public void dispatchPlus(Plus p) {
jtulach@177:                 v.visitPlus(p);
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchNumber(Number n) {
jtulach@177:                 v.visitNumber(n);
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchMinus(Minus m) {
jtulach@177:                 if (v.visitUnknown(m)) {
jtulach@177:                     m.getFirst().visit(this);
jtulach@177:                     m.getSecond().visit(this);
jtulach@177:                 }
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchReal(Real r) {
jtulach@177:                 v.visitUnknown(r);
jtulach@177:             }
jtulach@177:         };
jtulach@177:     }
jtulach@177:     // END: visitor.clientprovider.dispatch.v3.l1
jtulach@177:     // BEGIN: visitor.clientprovider.dispatch.v3.l2
jtulach@266:     static Visitor create20(final Visitor.Version20 v) {
jtulach@177:         return new Visitor() {
jtulach@177:             @Override
jtulach@177:             public void dispatchPlus(Plus p) {
jtulach@177:                 v.visitPlus(p);
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchNumber(Number n) {
jtulach@177:                 v.visitNumber(n);
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchMinus(Minus m) {
jtulach@177:                 v.visitMinus(m);
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchReal(Real r) {
jtulach@177:                 v.visitUnknown(r);
jtulach@177:             }
jtulach@177:         };
jtulach@177:     }
jtulach@177:     // END: visitor.clientprovider.dispatch.v3.l2
jtulach@177:     // BEGIN: visitor.clientprovider.dispatch.v3.l3
jtulach@266:     static Visitor create30(final Visitor.Version30 v) {
jtulach@177:         return new Visitor() {
jtulach@177:             @Override
jtulach@177:             public void dispatchReal(Real r) {
jtulach@177:                 v.visitReal(r);
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchNumber(final Number n) {
jtulach@177:                 class RealWrapper implements Real {
jtulach@177:                     public double getValue() {
jtulach@177:                         return n.getValue();
jtulach@177:                     }
jtulach@177:                     public void visit(Visitor v) {
jtulach@177:                         n.visit(v);
jtulach@177:                     }
jtulach@177:                 }
jtulach@177:                 v.visitReal(new RealWrapper());
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchPlus(Plus p) {
jtulach@177:                 v.visitPlus(p);
jtulach@177:             }
jtulach@177: 
jtulach@177:             @Override
jtulach@177:             public void dispatchMinus(Minus m) {
jtulach@177:                 v.visitMinus(m);
jtulach@177:             }
jtulach@177:         };
jtulach@177:     }
jtulach@177:     // END: visitor.clientprovider.dispatch.v3.l3
jtulach@177: }