Is this better, or worse?

while (<DATA>) {
  chomp;
  my $was = $_;
  my %formulae = (C => sub { ((shift() * 9/5) + 32).'F' },
                  F => sub { ((shift() - 32) * 5/9).'C' });
  s{(.*)([CF])}{${\$formulae{$2}($1)}}; # Update: look, ma! No "e"
  print "$was is $_\n";
}
__DATA__
12C
13C
14C
15C
-40C
+32C
.5C
15.8C
60.44F
55.4F
-.7F
[download]