[antlr-interest] section identifiers

[David Brunton]

Thanks, Jim- your response pointed me in the right direction, I think.
Here's what the results look like, for anyone else who's flailing around
like I am:

  comment: 'begin' id=ID .* {input.LT(2).getText().equals($id.text)}? end
ID;
  ID: 'a'..'z'+;
  WS: (' '|'\n'|'\r')+ {$channel=HIDDEN;};

Best,
David.

PS. Any improvements would be welcome- I'm brand new to ANTLR :)

On Tue, Apr 1, 2008 at 1:10 PM, Jim Idle <jimi at temporal-wave.com> wrote:

>  You can either use a filtering lexer, or give your lexer some states
> using @lexer::header { int state; }. If all you want to do is capture the
> stuff in between the begin and end and return a token for it, then you could
> probably just use a filtering lexer, or if it really is just that simple,
> then just a rule to capture the being and end stuff with some embedded logic
> to only recognize the end when the following word matches the start word
> (which you will capture after 'being' and check for after 'end'.
>
>
>
> However, you might just find that awk does this just as well if this is
> all you need out of the file. If this is just part of a larger picture, then
> a single lexer rule for 'being' and a bit of custom code using input.LA()
> and input.consume() to find the end will do just as well.
>
>
>
> Jim
>
>
>
> *From:* antlr-interest-bounces at antlr.org [mailto:
> antlr-interest-bounces at antlr.org] *On Behalf Of *David Brunton
> *Sent:* Tuesday, April 01, 2008 8:52 AM
> *To:* antlr-interest at antlr.org
> *Subject:* [antlr-interest] section identifiers
>
>
>
> I am parsing some files that have sections demarcated with the "begin" and
> "end" at the start of a line, followed by a (matching) arbitrary identifier:
>
> <snip>
> begin foo
> some stuff
> some other stuff
> end but don't end the section!
> other stuff
> end foo
> </snip>
>
> I don't need to parse anything inside of the section.
>
> I imagine this is a fairly common problem- any pointers?
>
> Best,
> David.
>
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