[antlr-interest] New user

[Matt Benson]

This looks very helpful, plus, for some reason, I have
never been to this articles page!  This may have been
helpful all along!  doh!

Thanks,
Matt

--- John Allen Green <johnallengreen at yahoo.com> wrote:
> Antlr has a great feature called a "hidden token
> filter". You let the
> whitespace go through as tokens from your lexer, and
> then the filter
> decides what tokens go through to the parser for it
> to turn into nodes. At
> the same time, those "hidden tokens" which were
> filtered out are added as
> extra links hanging off the regular AST nodes. That
> way you can walk the
> AST for regular semantic work, and you can also
> examine AST nodes for
> attached hidden tokens. I use this heavily for my
> work.
> 
> In http://www.antlr.org/articles.html , look for
> "Preserving Whitespace
> During Translation".
> 
> Regards,
> John
> 
> 
> 
> --On 10/09/2002 2:34 PM -0700 Matt Benson wrote:
> 
> > I believe I begin to understand.  Accounting for
> > comments in the Java grammar, for example, would
> > necessitate liberally sprinkling the tokens
> throughout
> > the parser rules, to represent the fact that they
> can
> > occur anywhere.  The end of having the tokens in
> the
> > tree might not be worth the effort and resulting
> > unreadable parser rules, correct?  The other
> option
> > you mentioned, adding comments as attributes of
> nodes,
> > I do not understand.  Would this approach be
> > applicable to my situation and if so how is it
> most
> > easily accomplished?
> > 
> > TIA,
> > Matt
> > 
> 


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