performance penalty using case insensitivity

filmo has asked for the wisdom of the Perl Monks concerning the following question:

I was reading 'Mastering Regular Expression' and it stated that using 'i' for case insensitivity paid a large performance penalty. Is that still the case with the most recent versions of Perl? (the book was written in 1997)

Comment on performance penalty using case insensitivity

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Re: performance penalty using case insensitivity by mirod (Canon) on Aug 21, 2001 at 22:08 UTC
The performance penalty is still there. It is even more important in recent versions of perl as it prevents most optimisation from being performed. So by using it you loose a lot of the work that has been done to speed-up common regexps. Which does not mean that it is a problem in most cases. When in doubdt use Benchmark!	[reply]