/* Soot - a J*va Optimization Framework
* Copyright (C) 2003 Ondrej Lhotak
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
package soot.jimple.toolkits.callgraph;
import java.util.*;
/** Represents a subset of the edges in a call graph satisfying an EdgePredicate
* predicate.
* @author Ondrej Lhotak
*/
public class Filter implements Iterator<Edge>
{
private Iterator<Edge> source;
private EdgePredicate pred;
private Edge next = null;
public Filter( EdgePredicate pred ) {
this.pred = pred;
}
public Iterator<Edge> wrap( Iterator<Edge> source ) {
this.source = source;
advance();
return this;
}
private void advance() {
while( source.hasNext() ) {
next = (Edge) source.next();
if( pred.want( next ) ) {
return;
}
}
next = null;
}
public boolean hasNext() {
return next != null;
}
public Edge next() {
Edge ret = next;
advance();
return ret;
}
public void remove() {
throw new UnsupportedOperationException();
}
}