|Perl: the Markov chain saw|
qr/STRING/ fails with certain lookbehind expressionsby wiewa (Initiate)
|on Jul 19, 2013 at 10:14 UTC||Need Help??|
wiewa has asked for the
wisdom of the Perl Monks concerning the following question:
I just run into quite an odd regex problem: I tried to compile a regex pattern with 'qr' which is case insensitive and contains a lookbehind assertion. If I have certain char combinations in my lookbehind expression, the regex engine throws the error:
Here some examples:
All patterns do what I'd expect if I don't compiled them.
Seems like the regex engine is interpreting the 'st' or 'ss' string as some meta-command, since no quantifier is used, that would cause a variable length.
I am using a new version of perl (v5.18.0). This problem did not occur in version v5.10.1.
Can anybody explain what is happening here? And is it maybe a known bug in perl version v5.18.0?