You know, that just pointed out the obvious to me. If I had this working properly.. It's not really perl anymore, is it.

We can look at somebody else's code, a subroutine, and we can have a good idea of where something returns. It seems the only safe way to do this would be to very explicitly name the function, something like warn_and_return_undef()- which kinda would beat the purpose of brevity- much better to actually warn and return undef.

I think this is what Fred P Brooks in the mythical man month (?) talks about in relation to sharpening tools that sharpen tools. A vicious programmer vice.