Comments on: How I remembered Object Thinking

By: Uberto

Uberto — Wed, 14 Dec 2011 14:06:33 +0000

Well I think all the DDD movement is the best place to discuss how to map OO on domain.
I also disagree with the recipe: “take the description of your problem, underline the nouns in the description, and these are your candidate objects”
I tried in the past and the result were orrible distribuited logic and god classes.
We need a maieutic approach in extracting objects from specification as Evans said.

By: Jacopo

Jacopo — Wed, 14 Dec 2011 13:01:19 +0000

“[..] It was a community of software agents, each one specialized in some symbolic solution technique, that worked at the problem without any central coordination [..]”

Here it comes a funny story.

I was wearing my “Anti-IF campaign” shirt (the one from Cirillo), and a friend of mine just asked “why polymorphism?” (stated on the back of the shirt). she studies chemistry and biology, so she was wondering if “my polymorphism” was related in any way with “her polymorphosm”: a property of cells, which can potentially act in many ways.

And the answer is: yes!

“[..] It’s object-oriented programming. [..] I thought of objects being like biological cells and/or individual computers on a network, only able to communicate with messages [..]”

— Dr. Alan Kay on the Meaning of “Object-Oriented Programming” (http://userpage.fu-berlin.de/~ram/pub/pub_jf47ht81Ht/doc_kay_oop_en)

Ciao!
-jacopo-

By: matteo

matteo — Wed, 14 Dec 2011 11:45:22 +0000

Seaside is certainly great stuff (even though it goes straight against my intuition about how web applications should work!) But I said that *SmallTalk* itself stopped evolving in 1980. If I’m not mistaken (I don’t know for sure) Squeak and Pharo are essentially reimplementation of the same language.

Alan Kay himself says, in his OOPSLA video The Computer Revolution Hasn’t Started Yet, that from 1970 to 1980 SmallTalk was reinvented every two years, but when they published SmallTalk-80 to the world, everyone thought “hey, this is SmallTalk, let’s learn it” rather than “let’s reinvent it” !

For instance, one fun thing Kay mentions in the Early History of SmallTalk is that he likes that in Prolog, even variables are objects that exhibit specific behaviours. This is a sample of what he means when he says that a key ingredient of OO is having access to meta-levels all the way through!

By: Moreno Carullo

Moreno Carullo — Wed, 14 Dec 2011 07:47:55 +0000

Great post, Matteo.

I agree 99.99% — the fundamentals of OOAD are certainly far more useful than any technology-specific stuff.

On the Smalltalk side, I also started toying with it (you know, Davide?) and a new world opened to me. But when you see a young guy like Avy Bryant releasing great stuff like Seaside, how can you say that Smalltalk development ended in the 80s? :-) (yes, this is the 0.01% bit missing!)

— Moreno

By: Carlo Garatti

Carlo Garatti — Wed, 14 Dec 2011 06:06:31 +0000

Great Matteo, i reach the same results without have your experience. In my opinion the key is A NEW WAY OF THINKING, a NEW mindset. the collaboration diagram of the cirillo’s workshop is not only a WAY for learn to think :D?