/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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.apache.commons.jexl2.parser;
import org.apache.commons.jexl2.DebugInfo;
import org.apache.commons.jexl2.JexlInfo;
/**
* Base class for parser nodes - holds an 'image' of the token for later use.
*
* @since 2.0
*/
public abstract class JexlNode extends SimpleNode implements JexlInfo {
/** A marker interface for literals.
* @param <T> the literal type
*/
public interface Literal<T> {
T getLiteral();
}
/** token value. */
public String image;
public JexlNode(int id) {
super(id);
}
public JexlNode(Parser p, int id) {
super(p, id);
}
/** {@inheritDoc} */
public DebugInfo debugInfo() {
JexlNode node = this;
while (node != null) {
if (node.value instanceof DebugInfo) {
return (DebugInfo) node.value;
}
node = node.jjtGetParent();
}
return null;
}
/** {@inheritDoc} */
public String debugString() {
DebugInfo info = debugInfo();
return info != null ? info.debugString() : "";
}
/**
* Whether this node is a constant node
* Its value can not change after the first evaluation and can be cached indefinitely.
* @return true if constant, false otherwise
*/
public final boolean isConstant() {
return isConstant(this instanceof JexlNode.Literal<?>);
}
protected boolean isConstant(boolean literal) {
if (literal) {
if (children != null) {
for (JexlNode child : children) {
if (child instanceof ASTReference) {
boolean is = child.isConstant(true);
if (!is) {
return false;
}
} else if (child instanceof ASTMapEntry) {
boolean is = child.isConstant(true);
if (!is) {
return false;
}
} else if (!child.isConstant()) {
return false;
}
}
}
return true;
}
return false;
}
}