Prototypes won't really help here. All they do is coerce the passed arguments into what you're expecting. You still have to document the API carefully so people are enlightened as much as possible. (I almost never use them.)

My point is that with using references directly, you'll get a better error message. If you're expecting an array reference and someone passes a hash reference, Perl will complain that you're doing arrayish operations on something that doesn't look like a hash. (If you're lucky, you won't get one of the obscure pseudohash errors...)

I'm not sure what you mean by figure out what type of variable a typeglob is aliasing to. You can use defined and exists on the typeglob slot to see if something's there and usable, but that has other subtleties and optimizations.

Checking the reference type with ref or UNIVERSAL::isa() is much better. It's much simpler.

Don't use prototypes unless you can clearly explain why you're using them. Their only significant benefit in Perl is to change how you call a subroutine, but they are so filled with caveats and gotchas that they're easy to use incorrectly. Read this recent thread on prototypes for more info, particularly the short and accurate explanation by Dominus.

As for using ref: I hate to say it, but I'd avoid that also. Take a look at code on this site that uses ref and you'll find that most (not all!) instances of it are indicative of some design flaw in the code.

Cheers,
Ovid

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