IDEAS for future rockit versions
--------------------------------
* SDF2ROCKIT - parses grammars written in SDF2 and converts them to Rockit
   format. There are a number of SDF2 grammars at 
     http://www.cwi.nl/~mdejonge/grammar-base/
* Make the spec of AST fully optional. If none are specified Rockti will 
   create as smart as possible. It should be possible to write out a new
   Rockit grammar with the Rockit-induced/guessed AstSpecs so that they can be
   hand-tuned.
* ANTLR-style tree walkers?
* Pretty-printer generator
* Trdtraversering genom att kombinera visitors:
	Visitor combination and traversal control
	Drs.ir. J.M.W. Visser ; 
	OOPSLA 2001
	http://dbs.cwi.nl:8080/cwwwi/owa/cwwwi.print_reports?ID=1148&type=1

* XPath-liknande stt att matcha p AST-trd?
	from http://www.w3.org/TR/xpath:
	"The primary purpose of XPath is to address parts of an XML [XML] 
	 document. "
	"XPath models an XML document as a tree of nodes."

    Example: With the XML tree

       [root]
           | -- movie
               | -- title
                   | -- X-Men
               | -- in case you didn't know...
               | -- cast
                   | -- Hugh Jackman, Patrick Stewart and Ian McKellen
               | -- director
                   | -- Bryan Singer
               | -- year
              	     | -- 2000
               | -- play_trailer

    the XPath

     /movie/cast/text()

    references

     Hugh Jackman, Patrick Stewart and Ian McKellen

    More info at
	http://www.devshed.com/Client_Side/XML/XPath/
	http://www.zvon.org/HTMLonly/XPathTutorial/General/examples.html
* Check the grammars at http://www.cwi.nl/~mdejonge/grammar-base/ and port them
  to rockit. Some of them should be very useful:

    C    - the language
    Dot  - format for graphviz dot files
    Java - the language (1.1)
    Yacc - 

  but start with SDF2 itself so that we can auto-translate the rest.     