http://www.perlmonks.org?node_id=432534


in reply to counting overlapping patterns

There's also the simple:

while ("AAAA" =~ /A(A+)/g) {
   $count += length($1);
}

[download]

Unlike C's strlen, Perl's length doesn't loop, so this snippet is compliant with your request for no further looping.

In Section Seekers of Perl Wisdom