#!/usr/bin/env perl
use Benchmark 'cmpthese';

my ($t1,$f,$t2)=(qr/people/,qr/babi?es/,qr/health(?:y|ful)/);

my %ways =
  (
   '3calls' => sub {/$t1/o && !/$f/o && /$t2/o},
   code     => sub {m:^(?(?{/$t1/o && !/$f/o && /$t2/o})|(?!)):},
   pos_look => sub {/(?=.*$t1)(?!.*$f)(?=.*$t2)/so},
   pos_anch => sub {/^(?=.*$t1)(?!.*$f)(?=.*$t2)/so},
   neg_look => sub {/(?!(?!.*$t1)|(?=.*$f)|(?!.*$t2))/so},
   neg_anch => sub {/^(?!(?!.*$t1)|(?=.*$f)|(?!.*$t2))/so},
   commit => sub {/$f(*COMMIT)(*FAIL)|^(?=.*$t1)(?=.*$t2).*$f(*COMMIT)(*FAIL)|(?=.*$t1)(?=.*$t2)/so}
  );

while (my ($way, $sub)=each %ways) {
  die "$way failed to match\n" unless ($_ = 'healthy people') && &$sub;
  die "$way had a false positive\n" if ($_= 'healthy people, including babies') && &$sub;
}

print "For matching:\n";
$_="Our people eat heathful meals.";
cmpthese(-1, \%ways);


print "For non-matching:\n";
$_="Healthy people have more babes in arms";
cmpthese(-1, \%ways);
__END__