1   /*
    2    * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
    3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
    4    *
    5    * This code is free software; you can redistribute it and/or modify it
    6    * under the terms of the GNU General Public License version 2 only, as
    7    * published by the Free Software Foundation.  Oracle designates this
    8    * particular file as subject to the "Classpath" exception as provided
    9    * by Oracle in the LICENSE file that accompanied this code.
   10    *
   11    * This code is distributed in the hope that it will be useful, but WITHOUT
   12    * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   13    * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   14    * version 2 for more details (a copy is included in the LICENSE file that
   15    * accompanied this code).
   16    *
   17    * You should have received a copy of the GNU General Public License version
   18    * 2 along with this work; if not, write to the Free Software Foundation,
   19    * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   20    *
   21    * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   22    * or visit www.oracle.com if you need additional information or have any
   23    * questions.
   24    */
   25   
   26   package com.sun.tools.javac.parser;
   27   
   28   import com.sun.tools.javac.util.Context;
   29   import com.sun.tools.javac.util.Log;
   30   import com.sun.tools.javac.util.Name;
   31   import com.sun.tools.javac.util.Names;
   32   
   33   import static com.sun.tools.javac.parser.Token.*;
   34   
   35   /**
   36    * Map from Name to Token and Token to String.
   37    *
   38    * <p><b>This is NOT part of any supported API.
   39    * If you write code that depends on this, you do so at your own risk.
   40    * This code and its internal interfaces are subject to change or
   41    * deletion without notice.</b>
   42    */
   43   public class Keywords {
   44       public static final Context.Key<Keywords> keywordsKey =
   45           new Context.Key<Keywords>();
   46   
   47       public static Keywords instance(Context context) {
   48           Keywords instance = context.get(keywordsKey);
   49           if (instance == null)
   50               instance = new Keywords(context);
   51           return instance;
   52       }
   53   
   54       private final Names names;
   55   
   56       protected Keywords(Context context) {
   57           context.put(keywordsKey, this);
   58           names = Names.instance(context);
   59   
   60           for (Token t : Token.values()) {
   61               if (t.name != null)
   62                   enterKeyword(t.name, t);
   63               else
   64                   tokenName[t.ordinal()] = null;
   65           }
   66   
   67           key = new Token[maxKey+1];
   68           for (int i = 0; i <= maxKey; i++) key[i] = IDENTIFIER;
   69           for (Token t : Token.values()) {
   70               if (t.name != null)
   71                   key[tokenName[t.ordinal()].getIndex()] = t;
   72           }
   73       }
   74   
   75   
   76       public Token key(Name name) {
   77           return (name.getIndex() > maxKey) ? IDENTIFIER : key[name.getIndex()];
   78       }
   79   
   80       /**
   81        * Keyword array. Maps name indices to Token.
   82        */
   83       private final Token[] key;
   84   
   85       /**  The number of the last entered keyword.
   86        */
   87       private int maxKey = 0;
   88   
   89       /** The names of all tokens.
   90        */
   91       private Name[] tokenName = new Name[Token.values().length];
   92   
   93       private void enterKeyword(String s, Token token) {
   94           Name n = names.fromString(s);
   95           tokenName[token.ordinal()] = n;
   96           if (n.getIndex() > maxKey) maxKey = n.getIndex();
   97       }
   98   }