Re: Class automators should be standard

[hardburn]

No. While I'm not going to say using MethodMaker is always bad, it would encourage those new to OOP to design sloppy objects (such as accessors and mutators on every attribute). Further, it only teaches you one aspect of Perl OOP. There are already too many people who limit themselves to bless alone, and with MethodMaker, they wouldn't even learn that much.

If you happen to like MethodMaker, know how bless works already, and already understand why you should limit the use of accessors/mutators, then go ahead and use MethodMaker. I just don't want coders encouraged into bad practices too soon. There's quite enough of that as it is.

[Arunbear]

Hmm..., how does one create objects without bless?

[ysth]

See blessless blessing. Or use a CPAN module to do it for you.

[hardburn]

First, you have to recognize that the OO concept is much larger than most object systems can handle. bless just happens to be the most common object system in Perl, but we can implement the same concepts without using it.

If you want no bless at all (not even hidden away by a module), there are a few ways to do it. You could simply have a hash that contains subroutine references along side its attributes, thus having a classless object.

Perl's tied interface has many attributes of an object system, its interface being the standard Perl operators (I don't recall off the top of my head if it uses bless anywhere, though). It's actually a pretty strong object system, since its very difficult to break encapsulation.

I've debated in the past if closures could be considered an object system. Here again, there is very strong encapsulation going on. I would agree with what others have noted, though, that calling closures an object system could limit their usefulness in your mind.

Then there are the various modules that do the blessing for you. Too many to list here, but trawling through the Class:: namespace should find a few.

The important point is not to limit yourself to Perl's common bless system. It's probably the most flexible of Perl's object system, but its also rather sucky (easy to break encapsulation, slow, etc.).

[theguvnor]

Arunbear asked how you do OOP in Perl without bless; I'd much rather know why you think it is important to know how to do that.

Update: looks like hardburn already answered the question.