anchor.diff:  
   
   BLOCK_COMMENT
  -   : BlockComment -> channel (OFF_CHANNEL)
  +   : BlockComment -> channel (COMMENT)
      ;
   
   
   LINE_COMMENT
  -   : LineComment -> channel (OFF_CHANNEL)
  +   : LineComment -> channel (COMMENT)
      ;
   
   // -------------------------
  
positive.code:          // -------------------------
           mode Tokens;
           TOK_DOC_COMMENT
              : DocComment -> type (DOC_COMMENT) , channel (OFF_CHANNEL)
              ;
           
           TOK_BLOCK_COMMENT
              : BlockComment -> type (BLOCK_COMMENT) , channel (OFF_CHANNEL)
              ;
           
           TOK_LINE_COMMENT
              : LineComment -> type (LINE_COMMENT) , channel (OFF_CHANNEL)
              ;
           
           TOK_LBRACE
  
negative.code:          // -------------------------
           mode Options;
           OPT_DOC_COMMENT
              : DocComment -> type (DOC_COMMENT) , channel (COMMENT)
              ;
           
           OPT_BLOCK_COMMENT
              : BlockComment -> type (BLOCK_COMMENT) , channel (COMMENT)
              ;
           
           OPT_LINE_COMMENT
              : LineComment -> type (LINE_COMMENT) , channel (COMMENT)
              ;
           
           OPT_LBRACE
  