I mentioned a possible speed-up when 'unrolling' the regexp.
Here's a small benchmark backing up that claim:
#!/usr/bin/perl
use strict;
use warnings;
use Benchmark 'cmpthese';
our $re1 = qr /"([^"\\]|\\.)*"/;
our $re2 = qr /"([^"\\]+|\\.)*"/;
our $re3 = qr /"[^"\\]*(\\.[^"\\]*)*"/;
chomp (our @data = <DATA>);
cmpthese -5 => {
plain => '/$re1/ for @data',
unroll1 => '/$re2/ for @data',
unroll2 => '/$re3/ for @data',
};
__DATA__
A "red" fish
A "red" fish and a "blue" fish
The book is called "A 5\" dwarf"
A backslash ("\\") and a forwardslash ("/")
No delimiters here at all.
The results:
Rate plain unroll1 unroll2
plain 50621/s -- -20% -38%
unroll1 63260/s 25% -- -22%
unroll2 81507/s 61% 29% --
Abigail
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