--- James Edward Gray II <[EMAIL PROTECTED]> wrote: > On Mar 10, 2004, at 10:20 AM, Stuart White wrote: > > > Geez, I can't recall them covering (?: ) in my > > books...D'oh! > > It may not have. It's not super common to see it > thrown about. Most > people just use (...), I would guess. >
Ahh, ok. So, like you said, (?: ) is just for grouping things. I can see how that might be useful. Thanks. > > The part about it grouping and > > capturing things makes sense, as it's the "cousin" > of > > ( ). The part about being able to include the |'s > > doesn't. I found out, without knowing at the > time, > > that the parentheses breakdown with |'s. I didn't > > know it at the time, but when I put the ORs in the > > parentheses and ran the program, I just got the > > command prompt, no output. > > Hmm. this still sounds a little confused. When I look at your regex, I think now that perhaps it wasn't the ( ) that were written incorrectly by me, but rather, my mistake in not accounting for the digits in the brackets where the Team is, or the .+ instead of just the . in between $2 and $3. this makes sense, because in Beginning Perl, it has quite a few examples of | within ( ), which is why I didn't think it'd be a problem in the first place. Let's us > another example: > The second regex: if (m/\[([A-Z0-9 -]+)\](\w+).+ (Steal|Assist|Block|replaced by):? (\w+)/) is what I want. This example makes sense too. > Notice that they are nearly identical matches, I > just changed the > (?:...) to (...) in the second one. They function > the same, the > variables set by the expression is the only > difference. (?:...) > doesn't set a variable. > Got it. > Your other confusion seems to be the | character. > You seem to think > it's a Perl or symbol. Not true. We're inside a > regex here, gotta > switch thinking. Regex knowledge in, Perl out. | > is a regex > alternation character, which pretty much means find > this or this, as > expected. That's probably why the symbol was > chosen, looks like the or > operators of many languages. However, note that & > isn't significant in > a regex. > Yup, simple mistake. It's been awhile since I read about | in regex, but I remember now that it is an alternation character. I certainly did get confused in my last post though. Thanks for the clarification. > Now, let's get to why | needs the (?:...) or (...) > around it. If they > weren't there, my regex would read like this: > This part I understood. I was confused before because I thought that (...) broke down when | was used, and that to circumvent that, one would use (?:...) instead. > You might take a trip back to the regex section of > your books, if | is > new to you. It's regex 101 and I would be super > surprised if it isn't > covered. > It's covered. I'll be looking at that at lunchtime. Thanks. > James > __________________________________ Do you Yahoo!? Yahoo! Search - Find what you’re looking for faster http://search.yahoo.com -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] <http://learn.perl.org/> <http://learn.perl.org/first-response>
