[antlr-interest] Re: woohoo! ParseTrees for free, Debugging for me!

[Ruslan Zasukhin]

on 11/30/03 9:16 PM, Terence Parr at parrt at cs.usfca.edu wrote:

>>> 
>>> Interesting idea, though I suspect that since derivations are specific
>>> to an input stream using $FIRST and $FOLLOW are more useful.
>> 
>> :-)
>> 
>> It will be great to have at least ANY simply example,
>> How to use ANTLR on this task.
> 
> Well, there is nothing automatic I'm afraid.  What one needs is a way
> to trace precisely where in a grammar the parse is at any moment.  Then
> one can ask "what can come next".  This could be auto-generated pretty
> easily I'd say by having ANTLR build a Map from grammar position to
> "next symbols" for every token reference in the grammar.  Then, in
> match() or whatever you'd set a variable called position.  Then you can
> query the Map to figure out what is next.
> 
> In the new ANTLR 3 stuff, you could keep around a copy of the grammar
> lookahead automaton so that you could just ask directly "what can come
> next".  Doesn't help you now, but in the future this kind of thing
> should be easy.

Then we will wait for 3.0  :-)

Thank you, Terrence.

-- 
Best regards,
Ruslan Zasukhin      [ I feel the need...the need for speed ]
-------------------------------------------------------------
e-mail: ruslan at paradigmasoft.com
web: http://www.paradigmasoft.com

To subscribe to the Valentina mail list go to:
http://lists.macserve.net/mailman/listinfo/valentina
-------------------------------------------------------------


 

Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/