anchor.diff:           // -------------------------
            mode Options;
            OPT_DOC_COMMENT
  -            : DocComment -> type (DOC_COMMENT) , channel (OFF_CHANNEL)
  +            : DocComment -> type (DOC_COMMENT) , channel (COMMENT)
               ;
            
            OPT_BLOCK_COMMENT
  -            : BlockComment -> type (BLOCK_COMMENT) , channel (OFF_CHANNEL)
  +            : BlockComment -> type (BLOCK_COMMENT) , channel (COMMENT)
               ;
            
            OPT_LINE_COMMENT
  -            : LineComment -> type (LINE_COMMENT) , channel (OFF_CHANNEL)
  +            : LineComment -> type (LINE_COMMENT) , channel (COMMENT)
               ;
            
            OPT_LBRACE
  
positive.code:          mode Channels;
           // currently same as Tokens mode; distinguished by keyword
           CHN_DOC_COMMENT
              : DocComment -> type (DOC_COMMENT) , channel (OFF_CHANNEL)
              ;
           
           CHN_BLOCK_COMMENT
              : BlockComment -> type (BLOCK_COMMENT) , channel (OFF_CHANNEL)
              ;
           
           CHN_LINE_COMMENT
              : LineComment -> type (LINE_COMMENT) , channel (OFF_CHANNEL)
              ;
           
           CHN_LBRACE
  
negative.code: 
  
  BLOCK_COMMENT
     : BlockComment -> channel (COMMENT)
     ;
  
  
  LINE_COMMENT
     : LineComment -> channel (COMMENT)
     ;
  
  // -------------------------
  