001    /**
002     * Closed parenthesis token singleton
003     *
004     * @author  Mathias Ricken
005     */
006    package sysModel.parser;
007    
008    /**
009     * Closing parenthesis token.
010     *
011     * @author Mathias Ricken
012     */
013    public final class CloseToken implements IToken {
014        /**
015         * Singleton instance.
016         */
017        private static CloseToken _instance;
018    
019        /**
020         * Return singleton instance.
021         *
022         * @return instance
023         */
024        public static synchronized CloseToken instance() {
025            if (null == _instance) {
026                _instance = new CloseToken();
027            }
028            return _instance;
029        }
030    
031        /**
032         * Private singleton constructor.
033         */
034        private CloseToken() {
035        }
036    
037        /**
038         * Execute visitor.
039         *
040         * @param v visitor
041         * @return visitor-specific return value
042         */
043        public Object execute(ITokenVisitor v) {
044            return v.closeCase();
045        }
046    }
047