Groovy example source code file (ASTNode.java)

This example Groovy source code file (ASTNode.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Groovy tags/keywords

astnode, groovybugerror, groovybugerror, listhashmap, listhashmap, no, object, object, runtimeexception, string, tried, tried

The Groovy ASTNode.java source code

/*
 * Copyright 2003-2007 the original author or authors.
 *
 * 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.codehaus.groovy.ast;

import org.codehaus.groovy.GroovyBugError;
import org.codehaus.groovy.util.ListHashMap;

/**
 * Base class for any AST node. This class supports basic information used in all
 * nodes of the AST<ul>
 * <li> line and column number information. Usually a node represents a certain
 * area in a text file determined by a starting position and an ending position.
 * For nodes that do not represent this, this information will be -1. A node can
 * also be configured in its line/col information using another node through 
 * setSourcePosition(otherNode).</li>
 * <li> every node can store meta data. A phase operation or transform can use 
 * this to transport arbitrary information to another phase operation or 
 * transform. The only requirement is that the other phase operation or transform
 * runs after the part storing the information. If the information transport is 
 * done it is strongly recommended to remove that meta data.</li> 
 * </ul>
 * <li> a text representation of this node trough getText(). This was in the 
 * past used for assertion messages. Since the usage of power asserts this 
 * method will not be called for this purpose anymore and might be removed in
 * future versions of Groovy</li>
 * @author <a href="mailto:james@coredevelopers.net">James Strachan
 * @author <a href="maito:blackdrag@gmx.org>Jochen "blackdrag" Theodorou
 * @version $Revision: 21228 $
 */
public class ASTNode {

    private int lineNumber = -1;
    private int columnNumber = -1;
    private int lastLineNumber = -1;
    private int lastColumnNumber = -1;
    private ListHashMap metaDataMap = new ListHashMap(); 

    public void visit(GroovyCodeVisitor visitor) {
        throw new RuntimeException("No visit() method implemented for class: " + getClass().getName());
    }

    public String getText() {
        return "<not implemented yet for class: " + getClass().getName() + ">";
    }

    public int getLineNumber() {
        return lineNumber;
    }

    public void setLineNumber(int lineNumber) {
        this.lineNumber = lineNumber;
    }

    public int getColumnNumber() {
        return columnNumber;
    }

    public void setColumnNumber(int columnNumber) {
        this.columnNumber = columnNumber;
    }

    public int getLastLineNumber() {
        return lastLineNumber;
    }

    public void setLastLineNumber(int lastLineNumber) {
        this.lastLineNumber = lastLineNumber;
    }

    public int getLastColumnNumber() {
        return lastColumnNumber;
    }

    public void setLastColumnNumber(int lastColumnNumber) {
        this.lastColumnNumber = lastColumnNumber;
    }
    
    /**
     * Sets the source position using another ASTNode.
     * The sourcePosition consists of a line/column pair for
     * the start and a line/column pair for the end of the
     * expression or statement 
     * 
     * @param node - the node used to configure the position information
     */
    public void setSourcePosition(ASTNode node) {
        this.columnNumber = node.getColumnNumber();
        this.lastLineNumber = node.getLastLineNumber();
        this.lastColumnNumber = node.getLastColumnNumber();
        this.lineNumber = node.getLineNumber();
    }
    
    /**
     * Gets the node meta data. 
     * 
     * @param key - the meta data key
     * @return the node meta data value for this key
     */
    public Object getNodeMetaData(Object key) {
        return metaDataMap.get(key);
    }
    
    /**
     * Copies all node meta data from one node to the other
     * @param other - the other node
     */
    public void copyNodeMetaData(ASTNode other) {
        metaDataMap.putAll(other.metaDataMap);
    }
    
    /**
     * Sets the node meta data. 
     * 
     * @param key - the meta data key
     * @param value - the meta data value
     * @throws GroovyBugError if key is null or there is already meta 
     *                        data under that key
     */
    public void setNodeMetaData(Object key, Object value) {
        if (key==null) throw new GroovyBugError("Tried to set meta data with null key on "+this+".");
        Object old = metaDataMap.put(key,value);
        if (old!=null) throw new GroovyBugError("Tried to overwrite existing meta data "+this+".");
    }
    
    /**
     * Removes a node meta data entry.
     * 
     * @param key - the meta data key
     * @throws GroovyBugError if the key is null
     */
    public void removeNodeMetaData(Object key) {
        if (key==null) throw new GroovyBugError("Tried to remove meta data with null key "+this+".");
        metaDataMap.remove(key);
        if (metaDataMap.size()==0) metaDataMap=null;
    }
}