/*

 * Copyright (c) 2002, 2008, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package com.sun.tools.javac.parser;

import com.sun.tools.javac.util.Context;

import com.sun.tools.javac.util.Log;

import com.sun.tools.javac.util.Name;

import com.sun.tools.javac.util.Names;

import static com.sun.tools.javac.parser.Token.*;

/**

 * Map from Name to Token and Token to String.

 *

 * If you write code that depends on this, you do so at your own risk.

 * This code and its internal interfaces are subject to change or

 * deletion without notice.</b>

 */

public class Keywords {

    public static final Context.Key<Keywords> keywordsKey =

        new Context.Key<Keywords>();

    public static Keywords instance(Context context) {

        Keywords instance = context.get(keywordsKey);

        if (instance == null)

            instance = new Keywords(context);

        return instance;

    }

    private final Names names;

    protected Keywords(Context context) {

        context.put(keywordsKey, this);

        names = Names.instance(context);

        for (Token t : Token.values()) {

            if (t.name != null)

                enterKeyword(t.name, t);

            else

                tokenName[t.ordinal()] = null;

        }

        key = new Token[maxKey+1];

        for (int i = 0; i <= maxKey; i++) key[i] = IDENTIFIER;

        for (Token t : Token.values()) {

            if (t.name != null)

                key[tokenName[t.ordinal()].getIndex()] = t;

        }

    }

    public Token key(Name name) {

        return (name.getIndex() > maxKey) ? IDENTIFIER : key[name.getIndex()];

    }

    /**

     * Keyword array. Maps name indices to Token.

     */

    private final Token[] key;

    /**  The number of the last entered keyword.

     */

    private int maxKey = 0;

    /** The names of all tokens.

     */

    private Name[] tokenName = new Name[Token.values().length];

    private void enterKeyword(String s, Token token) {

        Name n = names.fromString(s);

        tokenName[token.ordinal()] = n;

        if (n.getIndex() > maxKey) maxKey = n.getIndex();

    }

}