hg/apidesign: samples/visitor/11-cleanversion/src-api3.0/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 if (v instanceof Visitor30) {

    39                 ((Visitor30) 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 Visitor10) {

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

    62             } else if (v instanceof Visitor30) {

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

    64                 ((Visitor30) v).visitReal(wrapper);

    65             } else {

    66                 v.visitUnknown(this);

    67             }

    68         }

    69     }

    70     // BEGIN: visitor.nonmonotonic.Minus3

    71     /** @since 2.0 */

    72     public static final class Minus/*3.0*/ extends Expression {

    73         private final Expression first;

    74         private final Expression second;

    76         public Minus(Expression first, Expression second) {

    77             this.first = first;

    78             this.second = second;

    79         }

    80         public Expression getFirst() { return first; }

    81         public Expression getSecond() { return second; }

    83         public void visit(Visitor v) {

    84             if (v instanceof Visitor20) {

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

    86             } else if (v instanceof Visitor30) {

    87                 ((Visitor30)v).visitMinus(this);

    88             } else {

    89                 v.visitUnknown(this);

    90             }

    91         }

    92     }

    93     // END: visitor.nonmonotonic.Minus3

    94     // BEGIN: visitor.nonmonotonic.real

    95     /** @since 3.0 */

    96     public static final class Real extends Expression {

    97         private final double value;

    98         public Real(double value) {

    99             this.value = value;

   100         }

   101         public double getValue() {

   102             return value;

   103         }

   104         public void visit(Visitor v)

   105         // FINISH: visitor.nonmonotonic.real

   106         {

   107             if (v instanceof Visitor30) {

   108                 ((Visitor30)v).visitReal(this);

   109             } else {

   110                 v.visitUnknown(this);

   111             }

   112         }

   113     }

   116     public interface Visitor {

   117         public void visitUnknown(Expression e);

   118     }

   119     public interface Visitor10 extends Visitor {

   120         public void visitPlus(Plus s);

   121         public void visitNumber(Number n);

   122     }

   123     /** @since 2.0 */

   124     public interface Visitor20 extends Visitor {

   125         public void visitMinus(Minus s);

   126     }

   127     // BEGIN: visitor.nonmonotonic.visitor

   128     /** @since 3.0 */

   129     public interface Visitor30 extends Visitor {

   130         public void visitPlus(Plus s);

   131         public void visitMinus(Minus s);

   132         public void visitReal(Real r);

   133     }

   134     // END: visitor.nonmonotonic.visitor

   135 }

author	Jaroslav Tulach <jaroslav.tulach@apidesign.org>
	Thu, 30 Oct 2014 21:30:10 +0100
changeset 409	40cabcdcd2be
parent 175	7aaa7b256c7e
permissions	-rw-r--r--