hg/apidesign: samples/visitor/11-cleanversion/src-api3.0/org/apidesign/visitor/Language.java@db68b5a2636f

     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 Visitor1_0) {

    37                 ((Visitor1_0) v).visitPlus(this);

    38             } else if (v instanceof Visitor3_0) {

    39                 ((Visitor3_0) v).visitPlus(this);

    40             } else {

    41                 v.visitUnknown(this);

    42             }

    43         }

    44     }

    46     public static final class Number extends Expression {

    48         private final int value;

    50         public Number(int value) {

    51             this.value = value;

    52         }

    54         public int getValue() {

    55             return value;

    56         }

    58         @Override

    59         public void visit(Visitor v) {

    60             if (v instanceof Visitor1_0) {

    61                 ((Visitor1_0) v).visitNumber(this);

    62             } else if (v instanceof Visitor3_0) {

    63                 Real wrapper = new Real(getValue());

    64                 ((Visitor3_0) v).visitReal(wrapper);

    65             } else {

    66                 v.visitUnknown(this);

    67             }

    68         }

    69     }

    70     /** @since 2.0 */

    71     public static final class Minus extends Expression {

    72         private final Expression first;

    73         private final Expression second;

    75         public Minus(Expression first, Expression second) {

    76             this.first = first;

    77             this.second = second;

    78         }

    79         public Expression getFirst() { return first; }

    80         public Expression getSecond() { return second; }

    82         public void visit(Visitor v) {

    83             if (v instanceof Visitor2_0) {

    84                 ((Visitor2_0)v).visitMinus(this);

    85             } else if (v instanceof Visitor3_0) {

    86                 ((Visitor3_0)v).visitMinus(this);

    87             } else {

    88                 v.visitUnknown(this);

    89             }

    90         }

    91     }

    92     // BEGIN: visitor.nonmonotonic.real

    93     /** @since 3.0 */

    94     public static final class Real extends Expression {

    95         private final double value;

    96         public Real(double value) {

    97             this.value = value;

    98         }

    99         public double getValue() {

   100             return value;

   101         }

   102         public void visit(Visitor v)

   103         // FINISH: visitor.nonmonotonic.real

   104         {

   105         }

   106     }

   109     public interface Visitor {

   110         public void visitUnknown(Expression e);

   111     }

   112     public interface Visitor1_0 extends Visitor {

   113         public void visitPlus(Plus s);

   114         public void visitNumber(Number n);

   115     }

   116     /** @since 2.0 */

   117     public interface Visitor2_0 extends Visitor {

   118         public void visitMinus(Minus s);

   119     }

   120     // BEGIN: visitor.nonmonotonic.visitor

   121     /** @since 3.0 */

   122     public interface Visitor3_0 extends Visitor {

   123         public void visitPlus(Plus s);

   124         public void visitMinus(Minus s);

   125         public void visitReal(Real r);

   126     }

   127     // END: visitor.nonmonotonic.visitor

   128 }

author	Jaroslav Tulach <jtulach@netbeans.org>
	Sat, 14 Jun 2008 09:59:01 +0200
changeset 173	db68b5a2636f
parent 172	bb543d116467
child 174	3f3e772ccd52
permissions	-rw-r--r--