[cl-ppcre-devel] Buffered multi-line question

[Edi Weitz]

Hi Sébastien!

On Mon, 11 Oct 2004 18:52:56 +0200, Sébastien Saint-Sevin <seb-cl-mailist at matchix.com> wrote:

> I'm doing multi-lines regex searches over big files that can't be
> converted to single string.  So I introduced a kind of buffer that
> I'm using to search.
>
> Now, I need to add a constraint to scan, do-scans & others (in
> addition to (&key start end)) : I want to be able to specify to the
> engine that a scan must start before a certain index in the string
> (to avoid searching further results that will be cancelled later
> because of my buffered multi-line matching process).
>
> Logically, this :must-start-before value correspond to the first
> line of my buffer. If nothing starts at first line, I need to move
> the search one line forward, so everything that the engine would
> match later on in the string is wasted time.
>
> How can I do it ?

Have you considered using something like

  (?s:(?=.{n}))<actual-regular-expression>

where n obviously is an integer computed from your constraints above?
I don't know how this'll behave performance-wise but you could just
try it... :)

Or have I misunderstood your question? Actually, I'm not sure why the
END keyword parameter doesn't suffice. Can you give an example?

> PS: Edi, if you are back, my previous post is still an open question
> ;-) (the one with FILTER...)

Yes, I'm back but unfortunately I'm very busy with commercial stuff
right now. Sorry, filters will have to wait some more.

Cheers,
Edi.