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-representation-systems ).

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> 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> wrote:
> 
> 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
> 




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