Yes, indeed, a RE search without meta-characters is fast. But index is still faster:
$ perl index_regex_bench.pl
Rate Regex Index
Regex 5010020/s -- -23%
Index 6544503/s 31% --
This is one of the code versions I used, the one with which I obtained the above timings:
#!/usr/bin/perl
use Benchmark qw(:all);
use strict;
use warnings;
my $sentence = "The quick brown for jumps over the lazy dog";
my $results = timethese(5000000,
{
'Index' => \&code1,
'Regex' => \&code2,
},
'none'
);
cmpthese( $results ) ;
#------
sub code1 {
my $val = index $sentence, "fox" ;
}
#------
sub code2 {
my $val = ($sentence =~ /fox/);
}
Using a precompiled regex does not improve the speed of RE search in this case, quite the contrary.
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