Re^3: passing regular expression

It can also be faster (since qr// compiles up front)

But it still compiles onces. my $digit = '\d'; /$digit/; only compiles a regexp once as well. And so does my $digit = '\d'; /$digit/ for 1 .. 100000.

Note that my $digit = qr /\d/; /$digit/ if rand(2) < 1 always compiles a regexp once, m $digit = '\d'; /$digit/ if rand(2) < 1 compiles a regexp only 50% of the time.

Whether or not passing a pattern as a compile regexp or as string is faster depend on what the subroutine is doing with it. Compiling the pattern up front means you're going to pay the price, regardless whether you need it. Passing it as a string means you're only going to pay the price if pattern is actually needed as a regexp.

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Re^4: passing regular expression by ikegami (Patriarch) on Oct 08, 2009 at 17:27 UTC
my $digit = '\d'; /$digit/; only compiles a regexp once as well. Perhaps, but that's not the OP's usage. `my $digit = qr/\d/; foo($digit); # Compiles once my $digit = '\\d'; foo($digit); # Compiles any number of times` [download] Whether or not passing a pattern as a compile regexp or as string is faster depend on what the subroutine is doing with it. I said that in the post to which you are replying.	[reply] [d/l]
Re^4: passing regular expression by BioLion (Curate) on Oct 08, 2009 at 17:40 UTC
Totally OT, but if you hadn't noticed - your post is no. 800000 Just a something something...	[reply]