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Postings from September 2001
Ken wrote: > The way to approach this problem is to profile > Class::MultiMethods and figure out (a) where the hot spots > are and (b) what core support would help eliminate those > hot spots. But please don't do that until I release the next update of C::MM, which will use a new dispatch mechanism that is pluggable. > The one thing I'm curious about is whether different syntactic > conventions affect the dispatcher or whether this is all just > sugar for a single dispatch. Multiple dispatch is certainly not (practically) implementable via single dispatch. Oh, there *are* techniques, but they're subject to exponential blow-out in the number of intermediate methods required to resolve all possible dispatches. Syntactically, C::MM dispatches the call: $obj1->multimethod($obj2, $obj3); exactly the same as: multimethod($obj1, $obj2, $obj3); The only internal difference is that the first version has to do the normal Perl single dispatch look-up before it discovers that &multimethod is a multimethod (the second version doesn't), whilst the second version requires that &multimethod be declared a multimethod in the current scope (the first version doesn't). DamianThread Previous | Thread Next