Yes, with tied variables, even reading variables can have
side effects. I hope that perl6 will be
more friendly to IDEs. For example a tied variable
that has a side-effect should be flagged as dangerous
by an appropriate property.<o>
That's my main grief against Perl. Natural languages
come with an environment, so should computer languages.
Well, perlmonks is a social environment. That's already
something. :)