Re: Improve processing time for string substitutions

Like I already told you in the CB:

my $re = join "|", map { quotemeta $_ } keys %entitylist;
$re = qr/(?:$re)/;

# ...

$string =~ s/($re)/$entitylist{ $1 }/ge;
[download]

You might want to take a look at perlre for the /e switch.

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Re^2: Improve processing time for string substitutions by Anno (Deacon) on Apr 16, 2007 at 15:46 UTC
Is there a reason for the non-capturing parens in "`$re = qr/(?:$re)/;`"? What good does the /e switch do in the regex "`s/($re)/$entitylist{ $1 }/ge;`"? Anno	[reply] [d/l] [select]
Re^3: Improve processing time for string substitutions by ikegami (Patriarch) on Apr 16, 2007 at 15:56 UTC
No (`qr//` already adds non-capturing parens) and none (interpolation is done after each match).	[reply] [d/l]
Re^3: Improve processing time for string substitutions by Corion (Patriarch) on Apr 16, 2007 at 15:56 UTC
The `/e` switch is an error by me - it is a leftover from when I thought about doing the hex-conversion manually with a `sprintf` call in the right hand side.. I always build my regular expressions with noncapturing parentheses when I pal on latter assembling them - this prevents embarassing bug hunts later when I change how the target RE is built, possibly by repeating one ("atomic") building block - leaving out the parentheses causes hard-to-track misbehaviour with input on the seam of the two blocks. .	[reply] [d/l] [select]
Re^4: Improve processing time for string substitutions by Anno (Deacon) on Apr 16, 2007 at 16:06 UTC
I always build my regular expressions with noncapturing parentheses when I pal on latter assembling them - this ... Same here, but I've always thought of `qr//` as an alternative way to add those parens (which it does). You are, in effect, adding two pairs. Anno	[reply] [d/l]