package jp.ac.kobe_u.cs.prolog.builtin;
import java.io.PrintWriter;
import jp.ac.kobe_u.cs.prolog.lang.Arithmetic;
import jp.ac.kobe_u.cs.prolog.lang.BuiltinException;
import jp.ac.kobe_u.cs.prolog.lang.ExistenceException;
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.NumberTerm;
import jp.ac.kobe_u.cs.prolog.lang.PInstantiationException;
import jp.ac.kobe_u.cs.prolog.lang.PermissionException;
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;
/**
* <code>tab/2</code><br>
*
* @author Mutsunori Banbara (banbara@kobe-u.ac.jp)
* @author Naoyuki Tamura (tamura@kobe-u.ac.jp)
* @version 1.0
*/
public class PRED_tab_2 extends Predicate {
/**
*
*/
private static final long serialVersionUID = 2404459398952020896L;
private Term arg1, arg2;
public PRED_tab_2(Term a1, Term a2, Predicate cont) {
arg1 = a1;
arg2 = a2;
this.cont = cont;
}
public PRED_tab_2() {
}
@Override
public void setArgument(Term[] args, Predicate cont) {
arg1 = args[0];
arg2 = args[1];
this.cont = cont;
}
@Override
public int arity() {
return 2;
}
@Override
public String toString() {
return "tab(" + arg1 + "," + arg2 + ")";
}
@Override
public Predicate exec(Prolog engine) {
engine.setB0();
Term a1, a2;
a1 = arg1;
a2 = arg2;
int n;
String s = "";
Object stream = null;
// Char
a2 = a2.dereference();
if (a2.isVariable()) {
throw new PInstantiationException(this, 2);
}
if (!a2.isInteger()) {
try {
a2 = Arithmetic.evaluate(a2);
} catch (BuiltinException e) {
e.goal = this;
e.argNo = 2;
throw e;
}
}
n = ((NumberTerm) a2).intValue();
// S_or_a
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, "");
}
// tab
for (int i = 0; i < n; i++) {
s += " ";
}
((PrintWriter) stream).print(s);
return cont;
}
}