4 ms·

Obviously Rust is in the 4'th school which I like to call "The Rust School". All kidding aside, I think for any regular working day programmer Rust is obviousl

by zaphar 9y ago

Obviously Rust is in the 4'th school which I like to call "The Rust School". All kidding aside, I think for any regular working day programmer Rust is obviously OOP. The debates are really just which parts of which favorite school of OOP you think Rust is inspired by. But what really matters is that Rust gives you: * Encapsulation * Polymorphism. * And Code Reuse. Which are the only three things anyone who reaches for OOP is really looking for anyway. As fun as the PL theory discussions are. (Kind of a Hobby for me at least) I think those are the bits that actually matter to the people who truly need an answer to the question "Is Rust OOP or not?"

steveklabnik 9y ago
> Obviously Rust is in the 4'th school which I like to call "The Rust School". Ha! But yeah, if you're going to claim Rust is OOP, I would argue that makes the most sense. > what really matters is that Rust gives you: Right, this is the "Java School" definition. However, when people talk about OOP this way, when they say "polymorphism", they mean "subtype polymorphism" not "parametric polymorphism." Take https://docs.oracle.com/javase/tutorial/java/IandI/polymorphism.html https://docs.oracle.com/javase/tutorial/java/IandI/polymorph... as an example. Rust's only sub-typing is for lifetimes. > As fun as the PL theory discussions are. I definitely agree that in some senses, this is academic. But at the same time, practitioners can be mis-led by using terms in a different way than they're used to. This is sort of the argument I'm making above; since many practitioners see "polymorphism" as being equal to "subtype polymorphism", calling other types of polymorphism "polymorphism" is a more academic, less user-focused distinction.
- zaphar 9y ago
  Oh dear. That java tutorial just reads wrong to me but that's probably because I've been burned too many times by conflating polymorphism with code reuse in the form of inheritance. I think the working programmer doesn't know or care though. They care about whether you can reuse code in some way. And whether you can substitute multiple implementations of an object act as one particular type. The specifics of how you reach either of those goals is all they want to know and the pedantry that us language geeks love to engage in just blows right past them.
  - steveklabnik 9y ago
    It's possible we've just interacted with different people; I've spoken to a lot that assume inheritance, specifically, and we get questions about it often. Anyway, thanks for a good discussion!
    - zaphar 9y ago
      It's highly possible. I almost never get to work with people who geek out over language theory :-D I have to come to HN for that instead.
kibwen 9y ago
I agree that it's better to focus on encapsulation/polymorphism/reuse, but the reason why I personally object to the idea that "for any regular working day programmer Rust is obviously OOP" is because inheritance is usually taught above all of these as the fundamental property of OOP. I doubt I'm the only one whose high school and college exposure to OOP was to model "Dog is-a Mammal, Cow is-a Mammal, Mammal is-a Animal", and if a newcomer to Rust tries to do the same as their "hello world" then they're going to be greatly frustrated. Again, this isn't to say that the phrase "Rust is OOP" is necessarily incorrect, only that it's going to backfire if we going around shouting it, due to misaligned expectations.
- zaphar 9y ago
  Is-A does not and should not imply Inheritance. It merely implies polymorphism. I didn't get formally trained so I can't comment on what college/high school's teach but if they teach that Is-A relationships imply Inheritance then claiming Rust is OOP seems like a good way to educate the mis-educated regarding the difference.
  - kibwen 9y ago
    I don't think that "is-a" is formally defined anywhere. In my school experience, using Java specifically, "is-a" was used to teach the `extends` keyword, while "has-a" was used to teach the `implements` keyword.
  - leshow 9y ago
    What kind of polymorphism? Traditional OOP is subtype polymorphism. You can't really do that in Rust. It's main polymorphism is parametric and ad-hoc polymorphism a la Haskell. If that's considered OOP then OOP is so broad it's not a useful term
    - pjmlp 9y ago
      What is traditional OOP? The Simula, Smalltalk, Lisp, SELF or BETA model? Yes, OOP is broad, just like FP also is.
- 9y ago
tree_of_item 9y ago
> Encapsulation, Polymorphism, And Code Reuse. These are three incredibly vague terms that pretty much every programming language can be said to provide. I can't understand how you think OOP is defined by this. Do you think Haskell programmers are unable to reuse code? That they don't have any form of polymorphism? That they can't hide implementation details of functions, data structures and modules? This is the kind of argument that convinces me that OOP is completely bunk. Its adherents can't even explain what it is!
- zaphar 9y ago
  I wouldn't call myself an adherent. If anything I'm an adherent to the idea that Objects are just another Closure and vice versa. The interesting distinctions are in how they achieve those same goals. But most working programmers don't care about the debate at all in my experience. When they say they are looking for an object oriented language what they are really saying is: I am looking for a language that has a syntax where you can declare an object and call methods on that object usually with a dot but sometimes with an ->. They don't actually care about much more than that most of the time.
  - tree_of_item 9y ago
    > I'm looking for a language with "objects" and a syntax like <this> But why? That's such a weird thing to look for. Clearly there's a reason they think they want "objects", but what is it? And why the focus on what syntax these objects have?
    - zaphar 9y ago
      I'm not arguing this is a good thing. But I am saying that for the vast majority of programmers out there they use that pattern as a way of determining if they have those three attributes. It's cargo cult programming in a sense but it's also the only signal they've ever known.
      - leshow 9y ago
naasking 9y ago
> Which are the only three things anyone who reaches for OOP is really looking for anyway. Those are 3 characteristics of modularity, not object or class-specific in any meaningful sense. Rust isn't really a classic object-oriented language, but it is a modular language with object-like abstractions.

by zaphar 9y ago

steveklabnik 9y ago

> Obviously Rust is in the 4'th school which I like to call "The Rust School". Ha! But yeah, if you're going to claim Rust is OOP, I would argue that makes the most sense. > what really matters is that Rust gives you: Right, this is the "Java School" definition. However, when people talk about OOP this way, when they say "polymorphism", they mean "subtype polymorphism" not "parametric polymorphism." Take https://docs.oracle.com/javase/tutorial/java/IandI/polymorphism.html https://docs.oracle.com/javase/tutorial/java/IandI/polymorph... as an example. Rust's only sub-typing is for lifetimes. > As fun as the PL theory discussions are. I definitely agree that in some senses, this is academic. But at the same time, practitioners can be mis-led by using terms in a different way than they're used to. This is sort of the argument I'm making above; since many practitioners see "polymorphism" as being equal to "subtype polymorphism", calling other types of polymorphism "polymorphism" is a more academic, less user-focused distinction.

zaphar 9y ago
Oh dear. That java tutorial just reads wrong to me but that's probably because I've been burned too many times by conflating polymorphism with code reuse in the form of inheritance. I think the working programmer doesn't know or care though. They care about whether you can reuse code in some way. And whether you can substitute multiple implementations of an object act as one particular type. The specifics of how you reach either of those goals is all they want to know and the pedantry that us language geeks love to engage in just blows right past them.
- steveklabnik 9y ago
  It's possible we've just interacted with different people; I've spoken to a lot that assume inheritance, specifically, and we get questions about it often. Anyway, thanks for a good discussion!
  - zaphar 9y ago
    It's highly possible. I almost never get to work with people who geek out over language theory :-D I have to come to HN for that instead.

kibwen 9y ago

I agree that it's better to focus on encapsulation/polymorphism/reuse, but the reason why I personally object to the idea that "for any regular working day programmer Rust is obviously OOP" is because inheritance is usually taught above all of these as the fundamental property of OOP. I doubt I'm the only one whose high school and college exposure to OOP was to model "Dog is-a Mammal, Cow is-a Mammal, Mammal is-a Animal", and if a newcomer to Rust tries to do the same as their "hello world" then they're going to be greatly frustrated. Again, this isn't to say that the phrase "Rust is OOP" is necessarily incorrect, only that it's going to backfire if we going around shouting it, due to misaligned expectations.

zaphar 9y ago
Is-A does not and should not imply Inheritance. It merely implies polymorphism. I didn't get formally trained so I can't comment on what college/high school's teach but if they teach that Is-A relationships imply Inheritance then claiming Rust is OOP seems like a good way to educate the mis-educated regarding the difference.
- kibwen 9y ago
  I don't think that "is-a" is formally defined anywhere. In my school experience, using Java specifically, "is-a" was used to teach the `extends` keyword, while "has-a" was used to teach the `implements` keyword.
- leshow 9y ago
  What kind of polymorphism? Traditional OOP is subtype polymorphism. You can't really do that in Rust. It's main polymorphism is parametric and ad-hoc polymorphism a la Haskell. If that's considered OOP then OOP is so broad it's not a useful term
  - pjmlp 9y ago
    What is traditional OOP? The Simula, Smalltalk, Lisp, SELF or BETA model? Yes, OOP is broad, just like FP also is.
9y ago

tree_of_item 9y ago

> Encapsulation, Polymorphism, And Code Reuse. These are three incredibly vague terms that pretty much every programming language can be said to provide. I can't understand how you think OOP is defined by this. Do you think Haskell programmers are unable to reuse code? That they don't have any form of polymorphism? That they can't hide implementation details of functions, data structures and modules? This is the kind of argument that convinces me that OOP is completely bunk. Its adherents can't even explain what it is!

zaphar 9y ago
I wouldn't call myself an adherent. If anything I'm an adherent to the idea that Objects are just another Closure and vice versa. The interesting distinctions are in how they achieve those same goals. But most working programmers don't care about the debate at all in my experience. When they say they are looking for an object oriented language what they are really saying is: I am looking for a language that has a syntax where you can declare an object and call methods on that object usually with a dot but sometimes with an ->. They don't actually care about much more than that most of the time.
- tree_of_item 9y ago
  > I'm looking for a language with "objects" and a syntax like <this> But why? That's such a weird thing to look for. Clearly there's a reason they think they want "objects", but what is it? And why the focus on what syntax these objects have?
  - zaphar 9y ago
    I'm not arguing this is a good thing. But I am saying that for the vast majority of programmers out there they use that pattern as a way of determining if they have those three attributes. It's cargo cult programming in a sense but it's also the only signal they've ever known.
    - leshow 9y ago

naasking 9y ago

> Which are the only three things anyone who reaches for OOP is really looking for anyway. Those are 3 characteristics of modularity, not object or class-specific in any meaningful sense. Rust isn't really a classic object-oriented language, but it is a modular language with object-like abstractions.