| package jp.ac.kobe_u.cs.prolog.builtin; |
| import jp.ac.kobe_u.cs.prolog.lang.*; |
| /** |
| * <code>current_output/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_output_1 extends Predicate { |
| Term arg1; |
| |
| public PRED_current_output_1(Term a1, Predicate cont) { |
| arg1 = a1; |
| this.cont = cont; |
| } |
| public PRED_current_output_1() {} |
| |
| public void setArgument(Term[] args, Predicate cont){ |
| arg1 = args[0]; |
| this.cont = cont; |
| } |
| |
| public int arity() { return 1; } |
| |
| public String toString() { return "current_output(" + arg1 + ")"; } |
| |
| public Predicate exec(Prolog engine) { |
| engine.setB0(); |
| Term a1; |
| a1 = arg1; |
| a1 = a1.dereference(); |
| if (a1.isVariable()) { |
| ((VariableTerm)a1).bind(new JavaObjectTerm(engine.getCurrentOutput()), engine.trail); |
| } else if (a1.isJavaObject()) { |
| if (! a1.unify(new JavaObjectTerm(engine.getCurrentOutput()), engine.trail)) |
| return engine.fail(); |
| } else { |
| throw new IllegalDomainException(this,1,"stream",a1); |
| } |
| return cont; |
| } |
| } |