"I've been told that comments should amount for the half of your code"...
There's a style of programming where you make "executable comments" that also raise errors when something that should be true isn't: assertions in perl5.9.0.
# Take the square root of a number.
sub my_sqrt {
my($num) = shift;
# the square root of a negative number is imaginary.
assert($num >= 0);
return sqrt $num;
}
The above is from
Schwern's Carp::Assert. I think there are a number of other modules that do this as well, and I'm not sure which is best, because I only started experimenting with assertions myself recently. But it might be something to learn about if you are spending a lot of time meditating about commenting and error checking.