1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
|
package jp.ac.kobe_u.cs.prolog.builtin;
import jp.ac.kobe_u.cs.prolog.lang.*;
import java.util.Hashtable;
/**
<code>hash_get/3</code><br>
@author Mutsunori Banbara (banbara@kobe-u.ac.jp)
@author Naoyuki Tamura (tamura@kobe-u.ac.jp)
@version 1.0
*/
public class PRED_hash_get_3 extends Predicate.P3 {
private static final SymbolTerm SYM_NIL = SymbolTerm.makeSymbol("[]");
public PRED_hash_get_3(Term a1, Term a2, Term a3, Operation cont) {
arg1 = a1;
arg2 = a2;
arg3 = a3;
this.cont = cont;
}
public Operation exec(Prolog engine) {
engine.setB0();
Term a1, a2, a3;
a1 = arg1;
a2 = arg2;
a3 = arg3;
Object hash = null;
a1 = a1.dereference();
if (a1.isVariable()) {
throw new PInstantiationException(this, 1);
} else if (a1.isSymbol()) {
if (! engine.getHashManager().containsKey(a1))
throw new ExistenceException(this, 1, "hash", a1, "");
hash = ((JavaObjectTerm) engine.getHashManager().get(a1)).object();
} else if (a1.isJavaObject()) {
hash = ((JavaObjectTerm) a1).object();
} else {
throw new IllegalDomainException(this, 1, "hash_or_alias", a1);
}
if (! (hash instanceof HashtableOfTerm))
throw new InternalException(this + ": Hash is not HashtableOfTerm");
a2 = a2.dereference();
Term elem = ((HashtableOfTerm) hash).get(a2);
if (elem == null)
elem = SYM_NIL;
if (! a3.unify(elem, engine.trail))
return engine.fail();
return cont;
}
}
|
