Looking over my cow-orker's shoulder today, and criticising (those who can't do, teach!) I was pointing out to him that:
{
  local $" = '|';
  $good = $file =~ /^(@patterns)$/;
}

[download]
is around thirty times faster than 
for my $pattern (@patterns) {
  $good = 1, last if $file =~ /^$pattern$/
}

[download]
But he did have something curious in there, and (now to my point) I learned that  (?i:foo) does a case-insensitive non-remembering pattern match. I can't imagine if I'll ever use it, but I thought it was cute.

Has anyone else learned anything interesting today?

Jasper

In reply to You learn something every day by Jasper

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