Quite possibly.

The basic class hierarchy I'm working with makes good design sense and is essentially a tree of classes with one base class that is subclassed one or more times, each of those is subclassed zero or more times, plus another layer or two of subclasses beyond that on some branches. Currently there is no multiple inheritance (though I don't think I can completely rule that out for the future). I also can't rule out the possibility that the base class won't someday be a subclass of another class (such as a standard Perl class of some kind).

Each class in the hierarchy has a hash variable that contains a set of values that add to and/or overload the same set of values from the parent class. I'd like to have a function in the parent class that creates a merged hash and caches that value (on the first call) or returns the cached value (on subsequent calls). I'd rather not copy a lot of code to each class to do the merging and caching in each class.

I have the above working just fine when called at runtime, but if I try to create an instance of the base class as part of module compilation (i.e., my $obj = classname->new(...) code outside of any sub declaration, not using a BEGIN block), it doesn't work. (I suspect it has something to do with the order in which variables are declared and/or initialized.) Hence, I am changing it to create the required object the first time it needs it rather than at compile time.

As this is a one-time step, any costs involved in eval (which I've now removed because it wasn't needed) or autoload is negligible in this case. Even so, I'm trying to minimize the impact so that I can use this as a generalized auto-vivification and/or delayed initialization solution in the future.

In reply to Re^4: Automatic vivification of an object by bounsy
in thread Automatic vivification of an object by bounsy

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