Same here. At work, we've recently removed "use constant" from our code and converted to Readonly due to Damian's advice. It's really cleaned up a lot of our code.

Unfortunately, there are some bugs in how Perl handle tie which Readonly exposes. For example, the following prints "no":

#!/usr/bin/perl -l

use strict;
use warnings;

use Readonly;
Readonly my $VAR => 'SEARCH';

foreach my $var ($VAR) {
    print +($var eq $VAR) ? 'yes' : 'no';
}
[download]

Clearly that's wrong, but it's related to Perl's tie mechanism and not Readonly. As a workaround:

That's ugly as sin, but it works :(

Would "$var" eq "$VAR" work?

I just tested that. Yes, it works. Much nicer, too. Thanks.

Cheers,
Ovid

New address of my CGI Course.

Constants are different than normal variables, so I like how use constant constants look differently (due to lack of a sigil). Isn't that one of Perl's mantras?

Readonly uses tie. Tied variables are slower, and they behave erratically in a few situations.

On the other hand, Readonly works on types other than scalar.