ANTLR4 词法C++11 原始字符串

All，

我一直在尝试从标准文档 N4567 创建C++语法，这是我能找到的最新语法。 我相信语法是完整的，但我需要测试它。 我一直试图解决的一个问题是让词法分析器从标准中识别原始字符串。 我已经使用Actions & Semantic Predicates实现了一个可能的解决方案。 我需要帮助确定它是否真的有效。我已经阅读了关于操作和谓词之间交互的ANTLR4参考，但可以决定我的解决方案是否有效。 下面包括一个精简的语法。 任何想法将不胜感激。 我试图将我的想法包含在样本中。

grammar SampleRaw;
@lexer::members {
    string d_char_seq = "";
}
string_literal
        : ENCODING_PREFIX? '"' S_CHAR* '"'
        | ENCODING_PREFIX? 'R' Raw_String
        ;
ENCODING_PREFIX             //  one of
        : 'u8'
        | [uUL]
        ;
S_CHAR          /* any member of the source character set except the
                   double_quote ", backslash , or NEW_LINE character
                 */
        : ~["\nr]
        | ESCAPE_SEQUENCE
        | UNIV_CHAR_NAME
        ;
fragment ESCAPE_SEQUENCE
        : SIMPLE_ESCAPE_SEQ
        | OCT_ESCAPE_SEQ
        | HEX_ESCAPE_SEQ
        ;
fragment SIMPLE_ESCAPE_SEQ  // one of
        : '' '''
        | '' '"'
        | '' '?'
        | '' ''
        | '' 'a'
        | '' 'b'
        | '' 'f'
        | '' 'n'
        | '' 'r'
        | '' 't'
        | '' 'v'
        ;
fragment OCT_ESCAPE_SEQ
        : [0-3] ( OCT_DIGIT OCT_DIGIT? )?
        | [4-7] ( OCT_DIGIT )?
        ;
fragment HEX_ESCAPE_SEQ
        : '' 'x' HEX_DIGIT+
        ;
fragment UNIV_CHAR_NAME
        : '' 'u' HEX_QUAD
        | '' 'U' HEX_QUAD HEX_QUAD
        ;
fragment HEX_QUAD
        : HEX_DIGIT HEX_DIGIT HEX_DIGIT HEX_DIGIT
        ;
fragment HEX_DIGIT
        : [a-zA-Z0-9]
        ;
fragment OCT_DIGIT
        : [0-7]
        ;
/*
Raw_String
        : '"' D_CHAR* '(' R_CHAR* ')' D_CHAR* '"'
        ;
 */
Raw_String
        : ( /* CASE when D_CHAR is empty
               ACTION in D_CHAR_SEQ attempts to reset variable d_char_seq
               if it is empty, so handle it staticly
             */
            '"' 
                '('
                    ( ~[)]       // Anything but )
                    | [)] ~["]  // ) Actually OK, can't be followed by "
                                 //  - )" - these are the terminating chars
                    )* 
                ')' 
            '"'
          | '"'
                D_CHAR_SEQ  /* Will the ACTION in D_CHAR_SEQ be an issue for
                               the Semantic Predicates Below????
                             */
                    '('
                        ( ~[)]  // Anything but )
                        | [)] D_CHAR_SEQ { ( getText() !=  d_char_seq ) }?
                                /* ) Actually OK, can't be followed D_CHAR_SEQ match
                                   IF D_CHAR_SEQs match, turn OFF the Alternative
                                 */
                        | [)] D_CHAR_SEQ { ( getText() ==  d_char_seq ) }? ~["]
                                /* ) Actually OK, must be followed D_CHAR_SEQ match
                                     IF D_CHAR_SEQs match, turn ON the Alternative
                                     Cant't match the final " , but
                                     WE HAVE MATCHED OUR TERMINATING CHARS
                                 */
                        )*
                    ')'
                D_CHAR_SEQ /* No need to check here,
                              Matching Terminating CHARS is only way to get out 
                              of loop above
                            */
            '"'
          )
          { d_char_seq = ""; } // Reset Variable
        ;
/*
fragment R_CHAR
                // any member of the source character set, except a right
                // parenthesis ) followed by the initial D_CHAR*
                // (which may be empty) followed by a double quote ".
                // 
        : ~[)]
        ;
 */
fragment D_CHAR
                /* any member of the basic source character set except
                   space, the left parenthesis (, the right parenthesis ),
                   the backslash , and the control characters representing
                    horizontal tab, vertical tab, form feed, and newline.
                 */
        : ~[ )(\tvfnr]
        ;
fragment D_CHAR_SEQ
        : D_CHAR+ { d_char_seq = ( d_char_seq == "" ) ? getText() : d_char_seq ; }
        ;