Beefy Boxes and Bandwidth Generously Provided by pair Networks
go ahead... be a heretic

Re^3: Arbitrary number of captures in a regular expression

by Sidhekin (Priest)
on Sep 25, 2007 at 11:06 UTC ( #640897=note: print w/replies, xml ) Need Help??

in reply to Re^2: Arbitrary number of captures in a regular expression
in thread Arbitrary number of captures in a regular expression

Id do something like this myself. Except id probably not use look ahead and instead would approach it a different way.

I was annoyed with the lookahead myself, but it's unlikely to be a big deal, and I could not at the time see any way to avoid it. After some thinking, however, I believe I see a way to avoid looking ahead more than once -- just include it in the first alternation, which is matched precisely once on a successful match (anchored to the beginning of the string, and the only alternation that can match there):

my (@match) = $str =~ /(?:^foo (?=(?:m \d+ )+bar)|(?<!^)\G)m (\d+) /g;

... or, in the less-terse form:

my (@match) = $str =~ / (?: ^foo\ (?= (?:m\ \d+\ )+bar) # overall match from ^foo | (?<!^) \G # or continue from not-^ ) m\ (\d+)\ # grab each digit sequence /xg;

I think that's the best I got. Match that? :)

print "Just another Perl ${\(trickster and hacker)},"
The Sidhekin proves Sidhe did it!

Replies are listed 'Best First'.
Re^4: Arbitrary number of captures in a regular expression
by demerphq (Chancellor) on Sep 25, 2007 at 16:12 UTC

    I dont have time to put together a working example, but what i had in mind was using while, \G and also the /gc modifier in scalar context. Maybe from that you can come up with a working example, or prove me wrong, before I get the time to do anything useful with it.

    Using the underused /gc modifier was the key point I was thinking of tho.

    Oh and to be clear I wasnt trying to say my way would be better, just different. :-)


Log In?

What's my password?
Create A New User
Node Status?
node history
Node Type: note [id://640897]
[Corion]: marto: Oh, I'm jealous. I'm going to see DM in Frankfurt, but it's a stadium full of people, so, rather a big thing where you mostly get to see the band on screens ;)
[marto]: yes, the last time I saw them was in Berlin a few years ago, at the old Olympic stadium
[marto]: After Sunday I don't think I'll go see them again :)

How do I use this? | Other CB clients
Other Users?
Others lurking in the Monastery: (11)
As of 2017-03-24 11:34 GMT
Find Nodes?
    Voting Booth?
    Should Pluto Get Its Planethood Back?

    Results (301 votes). Check out past polls.