/*
* 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.JexlEngine;
import org.apache.commons.jexl2.JexlException;
/**
* The base class for parsing, manages the parameter/local variable frame.
* @author henri
*/
public class JexlParser extends StringParser {
/**
* The map of named registers aka script parameters.
* Each parameter is associated to a register and is materialized as an offset in the registers array used
* during evaluation.
*/
protected JexlEngine.Scope frame;
/**
* Sets the frame to use bythis parser.
* <p>
* This is used to allow parameters to be declared before parsing.
* </p>
* @param theFrame the register map
*/
public void setFrame(JexlEngine.Scope theFrame) {
frame = theFrame;
}
/**
* Gets the frame used by this parser.
* <p>
* Since local variables create new named registers, it is important to regain access after
* parsing to known which / how-many registers are needed.
* </p>
* @return the named register map
*/
public JexlEngine.Scope getFrame() {
return frame;
}
/**
* Checks whether an identifier is a local variable or argument, ie stored in a register.
* @param identifier the identifier
* @param image the identifier image
* @return the image
*/
public String checkVariable(ASTIdentifier identifier, String image) {
if (frame != null) {
Integer register = frame.getRegister(image);
if (register != null) {
identifier.setRegister(register.intValue());
}
}
return image;
}
/**
* Declares a local variable.
* <p>
* This method creates an new entry in the named register map.
* </p>
* @param identifier the identifier used to declare
* @param image the variable name
*/
public void declareVariable(ASTVar identifier, String image) {
if (frame == null) {
frame = new JexlEngine.Scope((String[])null);
}
Integer register = frame.declareVariable(image);
identifier.setRegister(register.intValue());
identifier.image = image;
}
/**
* Default implementation does nothing but is overriden by generated code.
* @param top whether the identifier is beginning an l/r value
* @throws ParseException subclasses may throw this
*/
public void Identifier(boolean top) throws ParseException {
// Overriden by generated code
}
final public void Identifier() throws ParseException {
Identifier(false);
}
public Token getToken(int index) {
return null;
}
void jjtreeOpenNodeScope(JexlNode n) {
}
/**
* Ambiguous statement detector.
* @param n the node
* @throws ParseException
*/
void jjtreeCloseNodeScope(JexlNode n) throws ParseException {
if (n instanceof ASTAmbiguous && n.jjtGetNumChildren() > 0) {
DebugInfo dbgInfo = null;
Token tok = this.getToken(0);
if (tok != null) {
dbgInfo = new DebugInfo(tok.image, tok.beginLine, tok.beginColumn);
} else {
dbgInfo = n.debugInfo();
}
throw new JexlException.Parsing(dbgInfo, "Ambiguous statement, missing ';' between expressions", null);
}
}
}