anchor.diff:      	doc=SHORTDOC*
           struct_add*
           TAG_END_STRUCT SHORTDOC*
  -        -> ^(CLASSDEF ^(DOC $doc) $name struct_add*)
  +        -> ^(CLASSDEF ^(DOC $doc?) $name struct_add*)
       ;
   
   // for the time being, bitflags are converted to enums
  
positive.code:         | TAG_END
          )
          SHORTDOC*
          -> ^(ENUMCONSTDEF ^(DOC $doc) $name $value)
      ;
  
  structdefine
  
negative.code:         doc=SHORTDOC*
          enum_option+
          TAG_END_ENUM SHORTDOC*
          -> ^(ENUMDEF ^(DOC $doc?) $name $type enum_option+)
      ;
  
  enum_option
  