hg/apidesign: samples/visitor/11-cleanversion/src-api2.0/org/apidesign/visitor/Language.java@40cabcdcd2be

     1 package org.apidesign.visitor;

     3 public final class Language {

     5     private Language() {

     6     }

     8     public static abstract class Expression {

    10         Expression() {

    11         }

    13         public abstract void visit(Visitor v);

    14     }

    16     public static final class Plus extends Expression {

    18         private final Expression first;

    19         private final Expression second;

    21         public Plus(Expression first, Expression second) {

    22             this.first = first;

    23             this.second = second;

    24         }

    26         public Expression getFirst() {

    27             return first;

    28         }

    30         public Expression getSecond() {

    31             return second;

    32         }

    34         @Override

    35         public void visit(Visitor v) {

    36             if (v instanceof Visitor10) {

    37                 ((Visitor10) v).visitPlus(this);

    38             } else {

    39                 v.visitUnknown(this);

    40             }

    41         }

    42     }

    44     public static final class Number extends Expression {

    46         private final int value;

    48         public Number(int value) {

    49             this.value = value;

    50         }

    52         public int getValue() {

    53             return value;

    54         }

    56         @Override

    57         public void visit(Visitor v) {

    58             if (v instanceof Visitor10) {

    59                 ((Visitor10) v).visitNumber(this);

    60             } else {

    61                 v.visitUnknown(this);

    62             }

    63         }

    64     }

    66     /** @since 2.0 */

    67     public static final class Minus extends Expression {

    68         private final Expression first;

    69         private final Expression second;

    71         public Minus(Expression first, Expression second) {

    72             this.first = first;

    73             this.second = second;

    74         }

    75         public Expression getFirst() { return first; }

    76         public Expression getSecond() { return second; }

    78         // BEGIN: visitor.cleanversion.dispatch2

    79         public void visit(Visitor v) {

    80             if (v instanceof Visitor20) {

    81                 ((Visitor20)v).visitMinus(this);

    82             } else {

    83                 v.visitUnknown(this);

    84             }

    85         }

    86         // END: visitor.cleanversion.dispatch2

    87     }

    89     // BEGIN: visitor.cleanversion.v2

    90     public interface Visitor {

    91         public void visitUnknown(Expression e);

    92     }

    93     public interface Visitor10 extends Visitor {

    94         public void visitPlus(Plus s);

    95         public void visitNumber(Number n);

    96     }

    97     /** @since 2.0 */

    98     public interface Visitor20 extends Visitor10 {

    99         public void visitMinus(Minus s);

   100     }

   101     // END: visitor.cleanversion.v2

   102 }

author	Jaroslav Tulach <jaroslav.tulach@apidesign.org>
	Thu, 30 Oct 2014 21:30:10 +0100
changeset 409	40cabcdcd2be
parent 170	206cdfeefeec
permissions	-rw-r--r--