Count non-empty hash values

pboin has asked for the wisdom of the Perl Monks concerning the following question:

I'm trying to improve my perl-fu a bit, and I think this is a case where I could map or grep. However, it's not working the way I think it should, and I could use a nudge...

Now, a FAQ is How do I find out if a hash is empty?. That's not exactly what I want to do. I have a hash, I know there are keys out there, but I want to get a quick count of how many of those keys have non-empty values.

Here's a mini-case that I think should work (but doesn't):

#!/usr/bin/perl
use strict;
use Data::Dumper::Simple;

my %a = (
    one => 'red',
    two => '',
    three => 'blue'
);

my @rtn = map {$a{$_} !~ /^$/;} keys(%a);
print Dumper(@rtn);
print "Keys w/ non-empty values: " . scalar(@rtn) . "\n";

__RESULTS__
@rtn = (
         1,
         1,
         ''
       );
Keys w/ non-empty values: 3
[download]

I think that the matching operator is having its results stored in @rtn. Then, when I get use that return in scalar context, the result isn't quite what I was looking for. Now I have to figure out how many non-empties are in my array instead of my hash, which is pretty much where I started.

Thank you Monasterians...

Back to Seekers of Perl Wisdom