package jp.ac.kobe_u.cs.prolog.builtin;
import jp.ac.kobe_u.cs.prolog.lang.IllegalDomainException;
import jp.ac.kobe_u.cs.prolog.lang.JavaObjectTerm;
import jp.ac.kobe_u.cs.prolog.lang.Predicate;
import jp.ac.kobe_u.cs.prolog.lang.Prolog;
import jp.ac.kobe_u.cs.prolog.lang.Term;
import jp.ac.kobe_u.cs.prolog.lang.VariableTerm;
/**
* <code>current_input/1</code><br>
*
* @author Mutsunori Banbara (banbara@kobe-u.ac.jp)
* @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
* @version 1.0
*/
public class PRED_current_input_1 extends Predicate {
/**
*
*/
private static final long serialVersionUID = 9011169850941382559L;
private Term arg1;
public PRED_current_input_1(Term a1, Predicate cont) {
arg1 = a1;
this.cont = cont;
}
public PRED_current_input_1() {
}
@Override
public void setArgument(Term[] args, Predicate cont) {
arg1 = args[0];
this.cont = cont;
}
@Override
public int arity() {
return 1;
}
@Override
public String toString() {
return "current_input(" + arg1 + ")";
}
@Override
public Predicate exec(Prolog engine) {
engine.setB0();
Term a1;
a1 = arg1;
a1 = a1.dereference();
if (a1.isVariable()) {
((VariableTerm) a1).bind(new JavaObjectTerm(engine
.getCurrentInput()), engine.trail);
} else if (a1.isJavaObject()) {
if (!a1.unify(new JavaObjectTerm(engine.getCurrentInput()),
engine.trail)) {
return engine.fail();
}
} else {
throw new IllegalDomainException(this, 1, "stream", a1);
}
return cont;
}
}