use warnings;
use strict;
use List::Util qw/ shuffle /;
use Time::HiRes qw/ gettimeofday tv_interval /;
use Test::More tests=>2;

my @looking_for = qw/ foo bar quz baz /;
my @looking_in = shuffle qw/ foo bar quz baz / x 100_000,
	qw/ some other stuff we're not looking for / x 2_000_000;

{
	my $t0 = [gettimeofday];
	my $found_count;
	for my $haystack (@looking_in) {
		for my $needle (@looking_for) {
			if ( $needle eq $haystack ) {
				$found_count++;
			}
		}
	}
	is $found_count, 400_000, 'linear scan';
	diag sprintf "that took %.3fs", tv_interval($t0);
}

{
	my $t0 = [gettimeofday];
	my $found_count;
	my %needles_hash = map { ($_=>1) } @looking_for;
	diag 'needles_hash: ', explain \%needles_hash;
	for my $haystack (@looking_in) {
		if ( $needles_hash{$haystack} ) {
			$found_count++;
		}
	}
	is $found_count, 400_000, 'hash lookup';
	diag sprintf "that took %.3fs", tv_interval($t0);
}

__END__

1..2
ok 1 - linear scan
# that took 2.274s
# needles_hash: {
#   'bar' => 1,
#   'baz' => 1,
#   'foo' => 1,
#   'quz' => 1
# }
ok 2 - hash lookup
# that took 0.599s

##</code><code>##

use warnings;
use strict;
use List::Util qw/ shuffle /;
use Time::HiRes qw/ gettimeofday tv_interval /;
use Test::More tests=>2;

my @looking_for = qw/ foo bar quz baz /;
my @looking_in = shuffle qw/ xyfooz abcbarx 123quzy abazz / x 10_000,
	qw/ some other stuff we're not looking for / x 100_000;

{
	my $t0 = [gettimeofday];
	my $found_count;
	for my $haystack (@looking_in) {
		for my $needle (@looking_for) {
			if ( $haystack =~ /\Q$needle\E/ ) {
				$found_count++;
			}
		}
	}
	is $found_count, 40_000, 'linear scan';
	diag sprintf "that took %.3fs", tv_interval($t0);
}

{
	my $t0 = [gettimeofday];
	my $found_count;
	my ($needles_regex) = map {qr/$_/} join '|', map {quotemeta}
		sort { length $b <=> length $a or $a cmp $b } @looking_for;
	diag "needles_regex: ", explain $needles_regex;
	for my $haystack (@looking_in) {
		if ( $haystack =~ $needles_regex ) {
			$found_count++;
		}
	}
	is $found_count, 40_000, 'regex';
	diag sprintf "that took %.3fs", tv_interval($t0);
}

__END__

1..2
ok 1 - linear scan
# that took 2.716s
# needles_regex: qr/bar|baz|foo|quz/
ok 2 - regex
# that took 0.212s