Re: Regex combining /(foo|bar)/ slower than using foreach (/foo/,/bar/) ???

Hi, I think the problem is with this line.

    my $regex               = qr /(?:$regexstr)/;
[download]

because perl compiles this patern again & again in the foreach loop.

    foreach my $stringlength (100,1000,10000,100000)
[download]

If you use this pattern

    my $regex               = qr /(?:$regexstr)/o;
[download]

instead of

    my $regex               = qr /(?:$regexstr)/;
[download]

It will be fast. Since it compiles the pattern only once.

Comment on Re: Regex combining /(foo\|bar)/ slower than using foreach (/foo/,/bar/) ??? Select or Download Code

Replies are listed 'Best First'.
Re^2: Regex combining /(foo\|bar)/ slower than using foreach (/foo/,/bar/) ??? by Roy Johnson (Monsignor) on Feb 18, 2005 at 13:14 UTC
No, Perl compiles the regex once where it is defined with `qr`. Caution: Contents may have been coded under pressure.	[reply] [d/l]