On Jul 16, 2009, at 12:04 PM, Lukas Renggli wrote: >>> Having an iterator class also avoids having to implement all these >>> iteration methods over and over again, e.g. in visitors. >> >> lukas do you have an example because I do not see why >> Also with traits you just have to implement do: and you get all the >> other one for free. > > The class and metaclass system of Smalltalk is already at the limit of > complexity that I can handle. Traits make this existing model even > more complicated. Even with support from a trait aware browser I find > traits extermely hard to use. To me the most important thing is that > at all points in time I know exactly what changes when I compile a > method. This is absolutely not clear when using traits.
I find your statements a bit rude. > > So far I haven't seen a single example where traits would really help. Really! I'm writing a trait to get magritte-aware xml output without having to always inherit from a top class or to copy and paste all the time the same code in my classes. > As Paolo suggested the problem can be simply solved by introducing an > Iterable superclass to Collection and Stream. I do not see how his solution will offer a faster implementation > Now you might say that this only works if I am not inheriting from > some other important class. True, an Iterable-trait would avoid that > problem. However, adding such a trait to an existing hierarchy looks > extremely scary to me. It potentially pollutes an existing protocol > with existing code that is most likely unrelated (or maybe it already > contains some iterator code for something else). like what collect: select: do: reject: inject:into: ? I think that you should also have a look at what other people are doing. > I believe, that in > this case *not* using traits forces you to do the right thing: > delegate to another object that knows how to iterate over your object. > >>> Is this going >>> to be ANSI? >> >> DNU? why ANSI has to be in the story? > > Paolo is in the ANSI committee, I though. Maybe that will be added? ANSI is dead. It was a bunch of specification pushed apart because smalltalk was hot and vendors wanted or not a feature in. _______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
