I just realized, that this isn't an original idea. Objective-C does this.
>From what I recall (hmm, must be close to 10 years now) it had the
same problem in finding the correct c routine to call for any
selector. Where the selector could be implemented in a seperate
objecte file.
Anyone on this list familiar with Objective-C and its dispatching method?
<chaim>
>>>>> "CF" == Chaim Frenkel <[EMAIL PROTECTED]> writes:
CF> Each sub has a unique number.
CF> Package A - Has nothing blessed, doesn't need the lookup table
CF> Package B - Has blessed items, lookup table for all subs that are part
CF> of the package, or in the inheritance tree.
CF> So this table would be sparse. But limited number, mapping
CF> sub unique number -> offset in vtbl
CF> Each object would then have a compact representation of only the methods
CF> that are accessible via method call. (Dynamically generated methods,
CF> would be added at the end of the vtbl.)
CF> There only has to be a single vtbl for all objects. Since all objects
CF> with the same @ISA would act the same.
CF> Does it sound workable?
CF> Hmm, I just thought of some scenerios that could break it.
CF> method A::a is redefined, all the pointers are now invalid. (A
CF> solution could be to leave a stub in place that would fixup the
CF> caller.)
CF> Dynamic changes to @ISA would invalidate all the vtbls. (Hmm, since
CF> there is only a single copy, changes to @ISA would rebuild the
CF> vtbl.)
CF> Package A inherits from Package B. Package A decides to dynamically
CF> define method A::a after several objects have already inherited a from
CF> B::a. (We could track all objects blessed into a package and do a
CF> fixup. But unless we need this list, for other reasons, it would be a
CF> waste just for this scenerio.)
CF> <chaim>
CF> --
CF> Chaim Frenkel Nonlinear Knowledge, Inc.
CF> [EMAIL PROTECTED] +1-718-236-0183
--
Chaim Frenkel Nonlinear Knowledge, Inc.
[EMAIL PROTECTED] +1-718-236-0183
