/*******************************************************************************
* Copyright (c) 2006, 2008 IBM Corporation and others.
* 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 org.eclipse.cdt.core.dom.lrparser.action;
import java.util.HashMap;
/**
* Maps token kinds from a sub-parser back to the corresponding
* token kinds in a base parser.
*
* @author Mike Kucera
*/
public class TokenMap implements ITokenMap {
// LPG token kinds start at 0
// the kind is not part of the base language parser
public static final int INVALID_KIND = -1;
private final int[] kindMap;
/**
* @param toSymbols An array of symbols where the index is the token kind and the
* element data is a string representing the token kind. It is expected
* to pass the orderedTerminalSymbols field from an LPG generated symbol
* file, for example C99Parsersym.orderedTerminalSymbols.
*/
public TokenMap(String[] toSymbols, String[] fromSymbols) {
// If this map is not being used with an extension then it becomes an "identity map".
if(toSymbols == fromSymbols) {
kindMap = null;
return;
}
kindMap = new int[fromSymbols.length];
HashMap<String,Integer> toMap = new HashMap<String,Integer>();
for(int i = 0, n = toSymbols.length; i < n; i++) {
toMap.put(toSymbols[i], i);
}
for(int i = 0, n = fromSymbols.length; i < n; i++) {
Integer kind = toMap.get(fromSymbols[i]);
kindMap[i] = kind == null ? INVALID_KIND : kind;
}
}
/**
* Maps a token kind back to the corresponding kind define in the base C99 parser.
*/
public int mapKind(int kind) {
if(kindMap == null)
return kind;
if(kind < 0 || kind >= kindMap.length)
return INVALID_KIND;
return kindMap[kind];
}
@Override
public String toString() {
StringBuilder sb = new StringBuilder('(') ;
boolean first = true;
for(int i = 0, n = kindMap.length; i < n; i++) {
if(!first)
sb.append(", "); //$NON-NLS-1$
sb.append(i).append('=').append(kindMap[i]);
first = false;
}
return sb.append(')').toString();
}
}