4 ms·

Entertaining. The presenter obviously doesn't like the class hierarchy to correspond to the domain model. He seems to think that this was an essential feature o

by Rochus 1y ago

Entertaining. The presenter obviously doesn't like the class hierarchy to correspond to the domain model. He seems to think that this was an essential feature of OOP, supported by some quotations by Smalltalk exponents. But not even the Smalltalk world could agree on what OOP actually is (just compare the statements by Kay with the actual architecture of Smalltalk-76ff) and as quickly as Smalltalk lost its significance, there is no need to mention it further. I would rather look at a reputable industry organization such as IEEE, which even publishes its own standards and best practices, what OOP is about. E.g. the OOP Milestone (see https://ethw.org/Milestones:Object-Oriented_Programming,_1961-1967 https://ethw.org/Milestones:Object-Oriented_Programming,_196...) which names Simula 67 the first OO language, specifies OO as "the combination of three main features: 1) encapsulation of data and code 2) inheritance and late binding 3) dynamic object generation." No mention of the class hierarchy should correspond to the domain model. So maybe we should just not mix up a programming paradigm with how it is used by some folks in practice? The fact that the loudest proponents of a paradigm are not usually those who apply it in practice remains true even today. Takes far less than 2.5 hours to state.

asa400 1y ago
He literally gives extensive primary source citations to show that the originators of OOP presented this class-domain correspondence as the correct way to think about and do OOP. Bjarne Stroustrup is not just some random guy.
- t420mom 1y ago
  Is it fair to blame all of OOP for C++?
  - anp 1y ago
    Maybe not fair, but it’s pretty normal for people to assess paradigms based on their most popular implementations.
  - throwawaymaths 1y ago
    yes, because java and c# (and others, python to a certain extent) basically copied it. even ruby, which at its core is about "message passing" sure does a hell of a lot to hide that and make it feel c++ ish. i would bet at least 25% of ruby practitioners arent aware that message passing is happening.
    - deleted 1y ago
      [deleted]
    - JohnMakin 1y ago
      at least python gives the flexibility to opt out of OOP, whereas in java, literally everything is an Object
      - throwawaymaths 1y ago
        that's why i said "to a certain extent" for python!!
      - Spivak 1y ago
        What do you mean by this? Because everything in Python is object, even classes and functions are objects. Do you just mean that Python lets you write functions not as part of a class? Because yeah there's the public static void main meme but static functions attached to a class is basically equivalent to Python free functions being attached to a module object.
        fc417fc802 1y ago
        If I call something a function does that mean I'm "doing functional programming" any time I use it? I use both C++ and Python but I wouldn't describe any of what I write as "object oriented".
        lisbbb 1y ago
        No. Functional programming is quite a bit more involved than just writing "functions"--it is taking advantage of the fact that functions are first-class "objects" that can be passed as arguments to other functions, which allows for a far more intuitive and flexible form of programming. But FP is even more than that.
  - lisbbb 1y ago
    I don't hate C++ as much as I hate Java, though. That probably has more to do wit the time I was working with C++ and the kinds of projects versus the mind-numbing corporate back-end garbage I worked on with Java.
- Rochus 1y ago
  > He literally gives extensive primary source citations to show that the originators of OOP presented this class-domain correspondence In case of Dahl/Nygaard it seems logical since their work focus was on simulation. Simula I was mostly a language suited to build discrete-event simulations. Simula 67, which introduced the main features we subsume under "Object-Orientation" today, was conceived as a general-purpose language, but still Dahl and Nygaard mostly used it for building simulations. It would be wrong to conclude that they recommended a class-domain correspondence for the general case. > Bjarne Stroustrup is not just some random guy Sure, but he was a Simula user himself for distributed systems simulation during his PhD research at Cambridge University. And he learned Simula during his undergraduate education at Aarhus, where he also took lectures with Nygaard (a simulation guy as well). So also here, not surprising that he used examples with class-domain correspondence. But there was also a slide in the talk where Stroustrup explicitly stated that there are other valid uses of OO than using it for modeling domains.
- igouy 1y ago
  The source citations are facts. We can check that Alan Kay "The Early History of Smalltalk" shows this on page 82: "Unfortunately, inheritance — though an incredibly powerful technique — has turned out to be very difficult for novices (and even professionals) to deal with." When the presenter tells us — 13:45 "he was already saying he kind of soured on it" — that is not a fact, it's speculation. That speculation does not seem to be supported by what follows in "The Early History of Smalltalk". One page later — "There were a variety of strong desires for a real inheritance mechanism from Adele and me, from Larry Tesler, who was working on desktop publishing, and from the grad students." page 83 And "A word about inheritance. … By the time Smalltalk-76 came along, Dan Ingalls had come up with a scheme that was Simula-like in it's semantics but could be incrementally changed on the fly to be in accord with our goals of close interaction. I was not completely thrilled with it because it seemed that we needed a better theory about inheritance entirely (and still do). … But no comprehensive and clean multiple inheritance scheme appeared that was compelling enough to surmount Dan's original Simula-like design." page 84
- igouy 1y ago
  Stroustrup's starting-point (page 13) is abstract-data-types not a compile-time-hierarchy — "Consider defining a type 'shape' for use in a graphics system. Assume for the moment that the system has to support circles, triangles, and squares. Assume also that you have some classes … You might define a shape like this … This is a mess. …" Then — "The problem is that there is no distinction between the general properties of any shape … and the properties of a specific shape … The ability to express this distinction and take advantage of it defines object-oriented programming. … The programming paradigm is: Decide which classes you want; provide a full set of operations for each class; make commonality explicit by using inheritance. … Where there is no such commonality, data abstraction suffices."
dimal 1y ago
Did you actually watch it? He talks A LOT more about Simula and C++ than Smalltalk. He goes back to the original sources: Kristen Nygaard and Bjarne Stroustrup. Seems odd to focus on Smalltalk when that’s not what the talk was about.
deleted 1y ago
[deleted]
phendrenad2 1y ago
It's funny because I read this comment and then watched the video, and it's like the first 15 minutes of the talk are dedicated to debunking this exact comment. Freaky.

by Rochus 1y ago

asa400 1y ago

He literally gives extensive primary source citations to show that the originators of OOP presented this class-domain correspondence as the correct way to think about and do OOP. Bjarne Stroustrup is not just some random guy.

t420mom 1y ago
Is it fair to blame all of OOP for C++?
- anp 1y ago
  Maybe not fair, but it’s pretty normal for people to assess paradigms based on their most popular implementations.
- throwawaymaths 1y ago
  yes, because java and c# (and others, python to a certain extent) basically copied it. even ruby, which at its core is about "message passing" sure does a hell of a lot to hide that and make it feel c++ ish. i would bet at least 25% of ruby practitioners arent aware that message passing is happening.
  - deleted 1y ago
    [deleted]
  - JohnMakin 1y ago
    at least python gives the flexibility to opt out of OOP, whereas in java, literally everything is an Object
    - throwawaymaths 1y ago
      that's why i said "to a certain extent" for python!!
    - Spivak 1y ago
      What do you mean by this? Because everything in Python is object, even classes and functions are objects. Do you just mean that Python lets you write functions not as part of a class? Because yeah there's the public static void main meme but static functions attached to a class is basically equivalent to Python free functions being attached to a module object.
      - fc417fc802 1y ago
        If I call something a function does that mean I'm "doing functional programming" any time I use it? I use both C++ and Python but I wouldn't describe any of what I write as "object oriented".
        lisbbb 1y ago
        No. Functional programming is quite a bit more involved than just writing "functions"--it is taking advantage of the fact that functions are first-class "objects" that can be passed as arguments to other functions, which allows for a far more intuitive and flexible form of programming. But FP is even more than that.
- lisbbb 1y ago
  I don't hate C++ as much as I hate Java, though. That probably has more to do wit the time I was working with C++ and the kinds of projects versus the mind-numbing corporate back-end garbage I worked on with Java.
Rochus 1y ago
> He literally gives extensive primary source citations to show that the originators of OOP presented this class-domain correspondence In case of Dahl/Nygaard it seems logical since their work focus was on simulation. Simula I was mostly a language suited to build discrete-event simulations. Simula 67, which introduced the main features we subsume under "Object-Orientation" today, was conceived as a general-purpose language, but still Dahl and Nygaard mostly used it for building simulations. It would be wrong to conclude that they recommended a class-domain correspondence for the general case. > Bjarne Stroustrup is not just some random guy Sure, but he was a Simula user himself for distributed systems simulation during his PhD research at Cambridge University. And he learned Simula during his undergraduate education at Aarhus, where he also took lectures with Nygaard (a simulation guy as well). So also here, not surprising that he used examples with class-domain correspondence. But there was also a slide in the talk where Stroustrup explicitly stated that there are other valid uses of OO than using it for modeling domains.
igouy 1y ago
The source citations are facts. We can check that Alan Kay "The Early History of Smalltalk" shows this on page 82: "Unfortunately, inheritance — though an incredibly powerful technique — has turned out to be very difficult for novices (and even professionals) to deal with." When the presenter tells us — 13:45 "he was already saying he kind of soured on it" — that is not a fact, it's speculation. That speculation does not seem to be supported by what follows in "The Early History of Smalltalk". One page later — "There were a variety of strong desires for a real inheritance mechanism from Adele and me, from Larry Tesler, who was working on desktop publishing, and from the grad students." page 83 And "A word about inheritance. … By the time Smalltalk-76 came along, Dan Ingalls had come up with a scheme that was Simula-like in it's semantics but could be incrementally changed on the fly to be in accord with our goals of close interaction. I was not completely thrilled with it because it seemed that we needed a better theory about inheritance entirely (and still do). … But no comprehensive and clean multiple inheritance scheme appeared that was compelling enough to surmount Dan's original Simula-like design." page 84
igouy 1y ago
Stroustrup's starting-point (page 13) is abstract-data-types not a compile-time-hierarchy — "Consider defining a type 'shape' for use in a graphics system. Assume for the moment that the system has to support circles, triangles, and squares. Assume also that you have some classes … You might define a shape like this … This is a mess. …" Then — "The problem is that there is no distinction between the general properties of any shape … and the properties of a specific shape … The ability to express this distinction and take advantage of it defines object-oriented programming. … The programming paradigm is: Decide which classes you want; provide a full set of operations for each class; make commonality explicit by using inheritance. … Where there is no such commonality, data abstraction suffices."

dimal 1y ago

Did you actually watch it? He talks A LOT more about Simula and C++ than Smalltalk. He goes back to the original sources: Kristen Nygaard and Bjarne Stroustrup. Seems odd to focus on Smalltalk when that’s not what the talk was about.

deleted 1y ago

[deleted]

phendrenad2 1y ago

It's funny because I read this comment and then watched the video, and it's like the first 15 minutes of the talk are dedicated to debunking this exact comment. Freaky.