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1 package kawa.lang;
2 import gnu.mapping.*;
3 import gnu.lists.*;
4 import java.io.*;
5 import gnu.text.Printable;
6
7 public class PairPat extends Pattern implements Printable, Externalizable
8 {
9 Pattern car;
10 Pattern cdr;
11 private int car_count, cdr_count;
12
13 public PairPat ()
14 {
15 }
16
17 public PairPat (Pattern car, Pattern cdr)
18 {
19 this.car = car;
20 this.cdr = cdr;
21 car_count = car.varCount ();
22 cdr_count = cdr.varCount ();
23 }
24
25 public static PairPat make (Pattern car, Pattern cdr)
26 {
27 return new PairPat (car, cdr);
28 }
29
30 public boolean match (Object  obj, Object [] vars, int start_vars)
31 {
32 if (! (obj instanceof Pair))
33 return false;
34 Pair pair = (Pair) obj;
35 return (car.match (pair.car, vars, start_vars)
36 && cdr.match (pair.cdr, vars, start_vars + car_count));
37 }
38
39 public void print (Consumer out)
40 {
41 out.write("#<pair-pattern car: ");
42 car.print(out);
43 out.write(" cdr: ");
44 cdr.print(out);
45 out.write('>');
46 }
47
48 public int varCount () { return car_count + cdr_count; }
49
50
53 public void writeExternal(ObjectOutput out) throws IOException
54 {
55 out.writeObject(car);
56 out.writeObject(cdr);
57 }
58
59 public void readExternal(ObjectInput in)
60 throws IOException, ClassNotFoundException
61 {
62 car = (Pattern) in.readObject();
63 cdr = (Pattern) in.readObject();
64 }
65 }
66 |
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