anchor.diff:     // that they are delimited by ' or " and so consume these
      // in their own alts so as not to inadvertantly match {}.
   
  -mode Action;
  +mode TargetLanguageAction;
   NESTED_ACTION
  -   : LBrace -> type (ACTION_CONTENT) , pushMode (Action)
  +   : LBrace -> type (ACTION_CONTENT) , pushMode (TargetLanguageAction)
      ;
   
   ACTION_ESCAPE
  
positive.code:    { handleBeginArgument(); }
     ;
     // -------------------------
     // Actions
  
  BEGIN_ACTION
     : LBrace -> pushMode (Action)
     ;
     // -------------------------
     // Keywords
  
negative.code:    : .
     ;
     // -------------------------
     // Target Language Actions
     //
     // Many language targets use {} as block delimiters and so we
     // must recursively match {} delimited blocks to balance the
  