org.drools.core.reteoo.TupleIterator Maven / Gradle / Ivy
/*
* Copyright 2010 Red Hat, Inc. and/or its affiliates.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.drools.core.reteoo;
public class TupleIterator {
public interface OnLeaf {
public void execute(LeftTuple leafLeftTuple);
}
public static void traverse(LeftTuple rootLeftTuple, LeftTuple leftTuple, OnLeaf onLeaf) {
boolean down = true;
while ( leftTuple != null ) {
while ( down ) {
// iterate to next leaf
if ( leftTuple.getFirstChild() != null ) {
leftTuple = leftTuple.getFirstChild();
} else {
down = false;
}
}
// we know we are at a leaf here
onLeaf.execute( leftTuple );
if ( leftTuple.getHandleNext() != null ) {
// iterate to next peer
leftTuple = leftTuple.getHandleNext();
// attempt to traverse that peer's children
if ( leftTuple.getFirstChild() != null ) {
down = true;
}
} else {
// iterate to parent's next peer and set down to find next leaf
// never go beyond the specified root node
while (leftTuple != rootLeftTuple && leftTuple.getHandleNext() == null) {
leftTuple = leftTuple.getLeftParent();
// onNode
}
leftTuple = leftTuple.getHandleNext();
down = true;
}
}
}
}