/*******************************************************************************
* Copyright (c) 2011 IBM Corporation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package com.ibm.wala.cast.js.ipa.callgraph.correlations.extraction;
import java.util.ArrayList;
import com.ibm.wala.cast.tree.CAstNode;
/**
* A node labeller keeps a mapping from nodes to integers to allow consistent labelling of nodes.
*
* @author mschaefer
*
*/
public class NodeLabeller {
private ArrayList<CAstNode> nodes = new ArrayList<CAstNode>();
/**
* Adds a node to the mapping if it is not present yet.
*
* @param node the node to add
* @return the node's label
*/
public int addNode(CAstNode node) {
int label = getLabel(node);
if(label == -1) {
label = nodes.size();
nodes.add(node);
}
return label;
}
/**
* Determines the label of a node in the mapping.
*
* @param node the node whose label is to be determined
* @return if the node is mapped, returns its label; otherwise, returns -1
*/
public int getLabel(CAstNode node) {
return nodes.indexOf(node);
}
/**
* Determines the node associated with a given label.
*/
public CAstNode getNode(int label) {
return nodes.get(label);
}
}