I'm just reading the doco for HTML::Template
Q: Why do you use /[Tt]/ instead of /t/i? It's so ugly!

A: Simple - the case-insensitive match switch is very inefficient. According to _Mastering_Regular_Expressions_ from O'Reilly Press, /[Tt]/ is faster and more space efficient than /t/i - by as much as double against long strings. //i essentially does a lc() on the string and keeps a temporary copy in memory. When this changes, and it is in the 5.6 development series, I will gladly use //i. Believe me, I realize /[Tt]/ is hideously ugly.

What's the story with that whole thing? I certainly read that in the Regex book ("The Owl Book"?) ages ago, but have been proceding on the assumption it got fixed, but I realise now that I've never seen it discussed.

Has it been fixed? If not, why not?

If it has, shouldn't modules and a bunch of other stuff have undergone a revision as a result?


($_='kkvvttuubbooppuuiiffssqqffssmmiibbddllffss')
=~y~b-v~a-z~s; print

In reply to Did the inefficiency of /i get fixed? by Cody Pendant

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