On Aug 13, [EMAIL PROTECTED] said: >Jeff 'Japhy' Pinyan wrote: >> On Aug 13, [EMAIL PROTECTED] said: >> >> my $data = shift; >> my $wrap_at = @_ ? shift : 75; >> > >I like that.
The simpler-looking my $wrap_at = shift || 75; has also been proposed. The only reason I didn't use that is because, in case you were ever in a situation where 0 was a valid value for your variable, you wouldn't want to use that || operator. >what is less awkward than [\s|\S] for 'match anything?' Well, for certain values of "less awkward", /(?s:.)/, which is the . metacharacter with the /s switch turned on -- that way it matches any character including newlines. I think someone suggested [.\n], but that is not correct, because . just means "." inside a character class. Another way to do it, if you are certain your input will have no multi-byte characters, is to use \C, which matches a single byte. >> EWW. DON'T USE $`. It's terrible. > >Okay, is that because it is slow and makes the rest of the regular >expressions afterwards run slowly? (I saw something about that in the >perlre document) Yes. When Perl compiles your program, it makes note of any use of $`, $&, or $'. If it sees you use it ONCE, ANYWHERE, it will make each regex prepare their values for you. Not cool. What is cool is that, even though $1, $2, etc. are the same way, they are provided only on a per-regex basis. >Is it as bad to use something like '(match anything)' before the main >expression, and using $1 in place of $` when it's useful? Well, if you're using a recent enough Perl (5.6+), you have access to the @- and @+ arrays, which hold offsets related to your last successful pattern match. $-[0] holds the offset in your string where the match started, so you could do my $pre = substr($str, 0, $-[0]); to get the equivalent of $`. See perlvar. >I think I'll review all my material again on regexes. Are there any >good books you recommend on how to use and think in regexes? "Mastering Regular Expressions", published by O'Reilly. -- Jeff "japhy" Pinyan [EMAIL PROTECTED] http://www.pobox.com/~japhy/ RPI Acacia brother #734 http://www.perlmonks.org/ http://www.cpan.org/ <stu> what does y/// stand for? <tenderpuss> why, yansliterate of course. [ I'm looking for programming work. If you like my work, let me know. ] -- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
