Well, I went truding around and I found these:

This first one was from a client who accidentally did something like: s/\n//g; to a few hundred text files. The files happened to be lists:

1) foo and his friend bar 2) Stuff and more (stuff) 3) More (and30) more (and) more 4) garbage (8) 5) some other things 6) (7lalala)
which turned into:
1) foo and his friend bar2) Stuff and more (stuff)3) More (and30) more + (and) more4) garbage (8)5) some other things6) (7lalala)
Anyways, it was my job to fix them. I was having a difficult time correctly parsing, but ended up solving the problem using your sexeger technique.
$text = reverse $copy; $text =~ s/ (?<= \) ) (\d+) (?= [^()]* \) ) /$1\n/gx; $text = reverse $text;
A few weeks later, for fun, I was able to solve the problem using a forward regex:
my $bal = # this is from perlre qr/ \( (?: (?> [^()]+ ) | (??{$bal}) )* \) /x; $text =~ s/ ( (?: (??{$bal}) [^(\d]* )* ) (\d+) (?= \) ) /$1\n$2/xg;

Which is exponentially uglier, and proves just how useful sexeger really is.

Another possibly useful example is a dealing from irc, where the person needed to perform a crude form escaping that involved stripping all backslashes that were between brackets. This solved his problem:

$text =~ s/ (?<= \[ ) ([^\]]*) (?= \] ) / strip_slash($1) /gex; sub strip_slash { $_=pop; s/\\//g; $_; }

Finally, theres a bunch of stuff at the end of Parsing with Perl 6 you might find useful...


In reply to Re: Regular Expressions: Call for Examples by jryan
in thread Regular Expressions: Call for Examples by japhy

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