[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message] Re: Seeking FSM for XML
Rick Marshall wrote: > which raises the other issue - a fsm controls something - ie some > states have effects - i presume you have a list of states and desired > effects that you want to plug into this fsm - but then yacc should > still be able to do that.... Tim Bray kindly sent me his DFA spec that he used in Lark. Tim has also now made his version available to the public, see his www.tbray.org/ongoing website or planet.xmlhack.com I have made an XML-syntax version of this: if Tim OK's it I will make that public shortly--I am checking it against the corrections to XML 1.0 and against XML 1.1. It should be a really good headstart to anyone wanting to experiment with parser design issues. You could use XSLT as the proprocessor to generate the code. Actually, there are still platforms which don't have strong XML processors available (or not open source ones): I was hearing of a home-made one written for PR/I systems using EBCDIC 2 weeks ago for example. Tim's spec does has various triggers for states and assumes some kind of stack: whether it is implemented using an actual pushdown automaton or some other arrangement with a stack is up to the implementer. Tim's implementation does not separate tokenizing and parsing really, except for keywords: consequently his DFA for DTDs is quite complex. I think a two level approach (e.g. tokenize "(" "#PCDATA" "|" "b" ")" "*" in the DFA and then have some higher PDA to parse these tokens into the declaration components) would be neater, but not faster. And it would have added to the complexity: if you have a tbale-basd system, you may as well use it to the full. Cheers Rick Jelliffe
|
PURCHASE STYLUS STUDIO ONLINE TODAY!Purchasing Stylus Studio from our online shop is Easy, Secure and Value Priced! Download The World's Best XML IDE!Accelerate XML development with our award-winning XML IDE - Download a free trial today! Subscribe in XML format
|