[comp.lang.objective-c] Do we really need types in OOPL's?

tma@osc.COM (Tim Atkins) (11/02/90)

As far as method lookup speed advantages possible with strong typing
some work I did in Objective C a couple of years ago may be of some
interest.  I attempted several improvments of the standard algorithm
and finally achieved a general lookup in the absence of strong typing
on the order of 15 assembler instructions on a Sun 3.  Adding type hints
(not strong typing but just a hint of the expected type of referenced
objects) and using code of the form:

	implementation = (runtime_type == expected_type) ? precomputed_imp :
		full_lookup(...);

cut the average lookup costs in half for the applications I instrumented.
Therefore, it seems to me that not strong typing, but weak type hints are
worthwhile for gaining improvements in this area.

- Tim Atkins