Boo.Lang.Parser.BooParserBase.stmt_modifier C# (CSharp) Method

        protected StatementModifier stmt_modifier()
        {
            StatementModifier m;

            IToken  i = null;
            IToken  u = null;
            IToken  w = null;

                m = null;
                Expression e = null;
                IToken t = null;
                StatementModifierType type = StatementModifierType.None;

            try {      // for error handling
            {
                switch ( LA(1) )
                {
                case IF:
                {
                    i = LT(1);
                    match(IF);
                    if (0==inputState.guessing)
                    {
                        t = i; type = StatementModifierType.If;
                    }
                    break;
                }
                case UNLESS:
                {
                    u = LT(1);
                    match(UNLESS);
                    if (0==inputState.guessing)
                    {
                        t = u; type = StatementModifierType.Unless;
                    }
                    break;
                }
                case WHILE:
                {
                    w = LT(1);
                    match(WHILE);
                    if (0==inputState.guessing)
                    {
                        t = w; type = StatementModifierType.While;
                    }
                    break;
                }
                default:
                {
                    throw new NoViableAltException(LT(1), getFilename());
                }
                 }
            }
            e=boolean_expression();
            if (0==inputState.guessing)
            {

                        m = new StatementModifier(ToLexicalInfo(t));
                        m.Type = type;
                        m.Condition = e;

            }
            }
            catch (RecognitionException ex)
            {
            if (0 == inputState.guessing)
            {
                reportError(ex, "stmt_modifier");
                recover(ex,tokenSet_14_);
            }
            else
            {
                throw ex;
            }
            }
            return m;
        }