Re: Re: Creating regex from arrays

I can see that you probably posted this as a TIMTOWTDI alternative to the half-million other posts using join. I would have never thought to do it that way. I wonder: does your method have an advantage over join, or is it just as good?

Once it's Turing complete, everything else is just syntactic sugar.

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Re: Re: Re: Creating regex from arrays by Zaxo (Archbishop) on Jul 30, 2003 at 03:08 UTC
You're right, timtowtdi sitting on my shoulder. I do like that construction, though. IMO, it's more concise and less visually noisy. True, it depends on a trick from the second tier of quote operator details, but I think the sparse notation and localization of `$"` pretty well telegraph what the trick is. I don't know if there is any performance benefit, other than what's obtained from constructing a compiled regex with qr//. That could as well be done with join. I've never benchmarked this. A minor refinement of the code, to assign $re where it is declared: `my $re = do { local $" = '\|'; qr/@array/; };` [download] or, if metacharacters may be a problem, `my $re = do { local $" = '\|'; qr/@{[map {quotemeta} @array]}/; };` [download] After Compline, Zaxo	[reply] [d/l] [select]

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Re: Re: Re: Creating regex from arrays
by Zaxo (Archbishop) on Jul 30, 2003 at 03:08 UTC

You're right, timtowtdi sitting on my shoulder. I do like that construction, though. IMO, it's more concise and less visually noisy. True, it depends on a trick from the second tier of quote operator details, but I think the sparse notation and localization of $" pretty well telegraph what the trick is.

I don't know if there is any performance benefit, other than what's obtained from constructing a compiled regex with qr//. That could as well be done with join. I've never benchmarked this.

A minor refinement of the code, to assign $re where it is declared:

my $re = do {
    local $" = '|';
    qr/@array/;
};
[download]

my $re = do {
    local $" = '|';
    qr/@{[map {quotemeta} @array]}/;
};
[download]

After Compline,
Zaxo

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