On Tue, Jul 12, 2005 at 08:48:41PM +0300, Gaal Yahas wrote: : I propose to throw away the filesystem coupling, and map from a more : general name of the bit of code we are requiring to a more general : description of which instance of it we actually got. Once modules return : interesting values, it might be useful to keep a copy of that value : somewhere on the value side of %*INC: or else turn it inside out and : stipulate that a standard field in the Module object is where you got : this particular module.
Yes, that's basically what I was mumbling about in my response. Now just make sure %*INC is lexically scoped. : Probably, %*INC values should be weak references. Why should they be weak references? If %*INC is lexically scoped then its entries represent this lexical scope's *real* references to modules, and there's no need to weaken them, since it's not functioning as some kind of cache. As long as this lexical scope sticks around, it needs the modules it points to. As soon as the lexical scope is destroyed, it doesn't need them any more. (Counting all closures over this lexical scope as preserving its needfulness, until all such closures are dead objects.) It's my conjecture that any explicit need for weak references probably indicates a design failure somewhere. Something like the mis-scoping of a reference variable, or maybe only something niggly like the absence of a feature like "is cached" to encapsulate weak semantics. Or maybe something as major as the lack of robust GC, in the case of Perl 5... Of course, *somebody* has to write the internals for "is cached". But we already know that all optimizations are a form of cheating. :-) Larry
