Hi Damien, Frames and Slots come from the AI world. The terms were defined by Marvin Minsky in his paper "A Framework for Representing Knowledge", Marvin Minsky, MIT-AI Laboratory Memo 306, June, 1974. ( https://web.media.mit.edu/~minsky/papers/Frames/frames.html). Minsky realized that the AI world was looking at ‘intelligence’ from a perspective of small pieces. He challenges the AI world to start looking at things in a bigger picture. One of his example’s is a chair. He believed we have a ‘Frame’ which is the general shape of a chair. The Chair frame has ‘slots’ which represent details of the chair. The contents of a slot can be another ‘frame’. In Smalltalk the Frame is analogous to a Class and a slot is somewhat analogous to an instance variable. A key paper which describes the implementation of frames and slots in the AI world is: "The Design Space of Frame Knowledge Representation Systems” by Peter Karp. ( https://www.sri.com/work/publications/design-space-frame-knowledge-represent... ). These are both old papers but they will give you the essence of what Frames and Slots from the AI world. In the 90’s there work done on the development of frame systems in Smalltalk. There are several very large Frame and Slot systems still in production. I hope this helps. Regards, Reg

On 18 Jul2018, at 8:39 AM, Damien Pollet <damien.pollet@gmail.com> wrote:

I understand what slots are, but haven't heard of frames in this context… can you elaborate ?

On Wed, 18 Jul 2018 at 13:44, Reg Krock via Pharo-dev <pharo-dev@lists.pharoorg <mailto:pharo-dev@lists.pharo.org>> wrote: The Slot class implementation is fundamentally sound but the larger constructs surrounding Frames and Slots still requires extensive thought.

I suspect that you will find that many more changes will be discovered as work is done with it.

Slots provide the capacity to implement most of AOP concepts in a simple manner. It also results in a Frame model.

I also would suggest careful examination of when to use composition versus traits with slots.

Regards

Reg Krock

...

On 17 Jul2018, at 1:44 PM, Sean P. DeNigris <sean@clipperadams.com <mailto:sean@clipperadams.com>> wrote:

tesonep@gmail.com <mailto:tesonep@gmail.com> wrote

...

the one that is disturbing, it is kept for compatibility with the old behavior

Are there enough users to justify backward compatibility if it costs a nice API?

----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html <http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html>

-- Damien Pollet type less, do more [ | ] http://people.untyped.org/damien.pollet <http://people.untyped.org/damien.pollet>