| package jp.ac.kobe_u.cs.prolog.builtin; |
| import jp.ac.kobe_u.cs.prolog.lang.*; |
| import java.io.PrintWriter; |
| /** |
| <code>set_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_set_output_1 extends Predicate { |
| |
| public Term arg1; |
| |
| public PRED_set_output_1(Term a1, Predicate cont) { |
| arg1 = a1; |
| this.cont = cont; |
| } |
| |
| public PRED_set_output_1(){} |
| |
| public void setArgument(Term[] args, Predicate cont) { |
| arg1 = args[0]; |
| this.cont = cont; |
| } |
| |
| public int arity() { return 1; } |
| |
| public String toString() { |
| return "set_output(" + arg1 + ")"; |
| } |
| |
| public Predicate exec(Prolog engine) { |
| engine.setB0(); |
| Term a1; |
| a1 = arg1; |
| Object stream = null; |
| |
| a1 = a1.dereference(); |
| if (a1.isVariable()) { |
| throw new PInstantiationException(this, 1); |
| } else if (a1.isSymbol()) { |
| if (! engine.getStreamManager().containsKey(a1)) |
| throw new ExistenceException(this, 1, "stream", a1, ""); |
| stream = ((JavaObjectTerm) engine.getStreamManager().get(a1)).object(); |
| } else if (a1.isJavaObject()) { |
| stream = ((JavaObjectTerm) a1).object(); |
| } else { |
| throw new IllegalDomainException(this, 1, "stream_or_alias", a1); |
| } |
| if (! (stream instanceof PrintWriter)) |
| throw new PermissionException(this, "output", "stream", a1, ""); |
| engine.setCurrentOutput((PrintWriter)stream); |
| return cont; |
| } |
| } |