Re: Your 'Class <Protocol>' Work

[Ziemowit Laski <zlaski at apple dot com>]

On 5 Oct 2004, at 9.34, David Ayers wrote:

> Ziemowit Laski wrote:
> > Took me longer than expected, but here is the alternative patch I
> > promised; no ChangeLog entries for now.  It's running a bit late, so
> > I'll defer my commentary until tomorrow. :-(  As always, feedback is
> > welcome.
>
> Hello Zem,
>
> well I guess we have different views on a gratuitous rewriting of
> objc_comptypes :-), but your version seems fine.

Good to hear it. :-)
> The test case you attached fails with the patch:
> Excess errors:
> [...]/class-protocol-1.m:50: warning: `+doItInstance1' not implemented
> by protocol(s)
> [...]/class-protocol-1.m:92: warning: no `+doItInstance3' method found
> [...]/class-protocol-1.m:133: warning: no `+doItInstance5' method found
> [...]/class-protocol-1.m:138: warning: `+doItInstance1' not implemented
> by protocol(s)
> [...]/class-protocol-1.m:195: warning: no `+doItInstance7' method found
> [...]/class-protocol-1.m:198: warning: `+doItInstance7' not implemented
> by protocol(s)
> [...]/class-protocol-1.m:230: warning: no `+doItInstance8' method found
> [...]/class-protocol-1.m:232: warning: no `+doItInstance9' method found

I could have sworn this worked for me, but I'll check again (and also
incorporate all of the comments you had below).
> You seem to have omitted the part which is /very/ important to me.
> Please! search for instance prototypes in protocol qualified Class
> references!  What is your issue with this feature?  It is very 
> important
> in my view wrt generating the right code.  I do not understand what is
> bothering you about it.  I can live with doing it independent of 
> whether
> the protocol is adopted by the root class.  But please do it for those
> that are.

My patch was only a work in progress (hence no ChangeLogs yet), but yes,
the protocols in question should be searched for a matching instance
prototype as a fallback, and if one is found, a suitable warning should
be issued.  If that yields no result either, then we give the "not 
implemented
by protocol(s)" warning and do the unadorned 'Class' search (which will 
give
us instance methods implemented by root classes).  I will do this in the
next rev of my patch; please stay tuned.

Note also that my patch intentionally skirts the various 
cleanup/renaming issues
we've discussed; we can do those later separately.  I also realized 
that my
suggestion for renaming 'reflexive' to 'symmetric' is wrong :-(; a 
symmetric
operation is one for which ((A op B) && (B op A)), whereas 
objc_comptypes()
is really implementing ((A op B) || (B op A)).  We really should rewrite
objc_comptypes() at some point so that it behaves more like C/C++ 
comptypes().

--Zem

--------------------------------------------------------------
Ziemowit Laski                 1 Infinite Loop, MS 301-2K
Mac OS X Compiler Group        Cupertino, CA USA  95014-2083
Apple Computer, Inc.           +1.408.974.6229  Fax .5477