5 ms·

Getting closer and closer to OOP

by jtrueb 1y ago

diggan 1y ago
At least they're not expanding the standard library for reading emails, yet...
- the_mitsuhiko 1y ago
  I'm a bit confused by both this comment and the previous one. Fundamentally nothing new is unlocked by this, that wasn't already possible for many years. It's just the ergonomics that got much better through this change.
  - BerislavLopac 1y ago
    The second comment refers to Zawinski's Law [0]. [0] https://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski's_Law https://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski's_Law
    - tialaramex 1y ago
      I can't speak for your parent but I'm aware of Zawinski's Law and I could see that's what the comment was about, but like your parent it's not at all clear to me why, it's a non-sequitur - this is giving Rust a convenient safe way to up cast, that's not anywhere in the ballpark of the sort of "expand to do everything" that Jamie was describing as inevitable. If you say "Ooh, the new kitten is learning how the cat flap works" and I respond "Those who cannot remember the past are condemned to repeat it" and then you respond with confusion that's because my quoting of Santayana is a non-sequitur. I might even agree with his sentiment about the importance of history, but the kitten learning how to use a cat flap isn't anywhere close to what Santayana was talking about so...
      - diggan 1y ago
        My jest wasn't meant to say that Rust is expanding to do everything, but rather the opposite. The comment I replied to somehow seems to believe Rust is becoming more "OOP", so I took it a step further and also referenced a fairly known pitfall for platforms (so doesn't even apply to programming languages, in my mind). In the end, it's a joke with no even a pinch of truth, which seems to have landed flat, that's on me I suppose.
      - capitol_ 1y ago
        Since rust is popular it naturally attracts a counter movement, so some people will grasp at straws in order to say something negative.
GolDDranks 1y ago
Just having features associated with OOP isn't a bad thing. Object upcasting has its uses. It's some of the other stuff that gets OOP its bad rap. Garbage collection, common in many OOP languages, enables having arbitrary object graphs. The programmer doesn't need to think hard about who has a reference to who, and how long these references live. This leads to performance-defeating pointer chasing, and fuzzy, not-well-thought-of object lifetimes, which in turn lead to accidental memory leaks. Additionally, references in major languages are unconditionally mutable. Having long-lived mutable references from arbitrary places makes it hard to track object states. It makes easier to end up in unexpected states, and accidentally violate invariants from subroutine code, which means bugs. Also, class-like functionality conflates data-layout, privacy/encapsulation, API, namespacing and method dispatch into a single thing. Untangling that knot and having control over these features separately might make a better design.
- jtrueb 1y ago
  I agree this is useful. I also think it isn’t the end of the world to support some semblance of OOP in Rust. If it helps you ship the business logic, sometimes it’s okay to concede some performance or other cost.
  - BrainInAJar 1y ago
    "sometimes" is doing a lot of work there. Sometimes it is, but also sometimes it isn't, and Rust at least gives you a choice (you can use Arc all over the place, or if performance is critical you can be more careful about specifying lifetimes)
    - jtrueb 1y ago
      Arc doesn’t give you the choice until this upcasting feature lands in stable.
- mightyham 1y ago
  You make some really good criticisms of OOP language design. I take issue with the part about garbage collecting, as I don't think your points apply well to tracing garbage collectors. In practice, the only way to have "memory leaks" is to keep strong references to objects that aren't being used, which is a form of logic bug that can happen in just about any language. Also good API design can largely alleviate handling of external resources with clear lifetimes (files, db connections, etc), and almost any decent OOP languages will have a concept of finalizers to ensure that the resources aren't leaked.
__s 1y ago
Do you consider Go OOP?
dullcrisp 1y ago
I love how OOP is considered a slur on here. It’s no wonder Alan Kay doesn’t come back.
- Rexxar 1y ago
  Why do you interpret this comment as anti-OOP ? I see it has criticising rust choice to not do OOP at the beginning to finally do it piece by price and that it would have probably be better for the language to embrace it from start.
  - dullcrisp 1y ago
    I don’t know how to interpret the comment, but that seems to be how the other responses interpret it.
- bfrog 1y ago
  Inherit is the first step to tell.
  - dullcrisp 1y ago
    I don’t disagree about inheritance.
Xeoncross 1y ago
Are we talking about functional OOP or class-less OOP or JavaScript's prototypal version of inheritance in OOP or Javas functions-are-evil OOP or some other version of OOP? Object-Oriented Programming is a spectrum with varying degrees of abuse.
bigstrat2003 1y ago
OOP is a good thing, not a bad thing. It enables you to use objects to represent relationships easily in a way that other paradigms don't. I agree that the trendiness of OOP was stupid (it isn't the right approach to every situation and it was never going to solve all our problems), but the way it's trendy to hate on OOP now is equally stupid. It's a good tool that sometimes makes sense and sometimes doesn't, not a savior or a devil.
- vlovich123 1y ago
  “Inheritance” of interfaces good *. Inheritance of stateful objects bad - composition is much better. The OOP model that Rust supports only supports the good kind of OOP and doesn’t support the bad kind. * technically rust doesn’t have interface inheritance but you can treat it that way and it’ll mostly look like that in an abstract sense.
  - jandrewrogers 1y ago
    I agree that composition is much better than inheritance for most typical code cases. However, there are cases where inheritance is absolutely the correct model and not having inheritance makes for worse code. I may not use inheritance very often (it rarely makes sense in a systems context) but it is nice to have it when it is unambiguously the right tool for the job. Most code paradigms exist because there is some code context where they are nearly ideal. Someone invented them to handle that case efficiently and elegantly. If you write diverse software long enough you will come across all of those contexts in real code. I’m the opposite of a model purist. I have a strong preference for a languages that let you efficiently switch models on a very granular basis as may be useful in the moment.
  - zozbot234 1y ago
    > The OOP model that Rust supports only supports the good kind of OOP and doesn’t support the bad kind. Well, almost. You can actually express "the bad kind of OOP" (i.e. implementation inheritance) in Rust quite elegantly via the generic typestate pattern! But that's still good, because it reveals the inherent complexity of your 'inheritance hierarchy' very clearly by modeling every part of it as a separate, possibly generic type. Hence why it's very rarely used in Rust, with interface inheritance being preferred instead. It mostly gets used in cases where the improved static checking made possible by the "typestate" pattern can be helpful, which has little to do with "OOP" design as generally understood.
echelon 1y ago
Rust has had significant OOP features since the beginning. Trait methods, dynamic dispatch, inheritance, bounds, etc.
quotemstr 1y ago
There's this dynamic in the industry in which a brash young project comes out swinging against some established technique and commits early to its opposite. Then, as the project matures, its authors begin to understand why the old ways were the way they were and slowly walk back their early stridency --- usually without admitting they're doing it. Consider Linux. Time was, metaprogramming was BAD, C was all you needed, we didn't need dynamic CPU schedulers, we didn't need multiple LSMs, and we sure as hell didn't need ABI stability. Now we have forms of all of these things (for the last, see CO-RE), because as it turns out, they're actually good. In Python, well, turns out multiprocessing isn't all you need, and a free-threaded Python has transitioned from impossible and unwanted to exciting and imminent. In transfer encodings, "front end" people thought that JSON was all you needed. Schemas? Binary encodings? Versioning? References? All for those loser XML weenies. Well, who's the weenie now? And in Rust? Well, let's see. Turns out monomorphization isn't all you need. Turns out that it is, in fact, occasionally useful to unify an object and its behavior in a runtime-polymorphic way. I expect yeet_expr to go through eventually too. Others are trying to stabilize (i.e. ossify) the notionally unstable ABI, just like they did to poor C++, which is now stuck with runtime pessimization because somebody is too lazy to recompile a binary from 2010. As surely as water will wet and fire will burn, the gods of Java with stupidity and complexity return.
- Rusky 1y ago
  > And in Rust? Well, let's see. Turns out monomorphization isn't all you need. Turns out that it is, in fact, occasionally useful to unify an object and its behavior in a runtime-polymorphic way. I expect yeet_expr to go through eventually too. Others are trying to stabilize (i.e. ossify) the notionally unstable ABI, just like they did to poor C++, which is now stuck with runtime pessimization because somebody is too lazy to recompile a binary from 2010. Not to make an argument either way on your general point, but these are really bad examples for Rust if you look at the specifics: Monomorphization was never the only option. Trait objects and vtables predate the RFC process itself. Early Rust wanted more dynamic dispatch than it eventually wound up with. The idea of a "throw"-like operator was introduced at the same time as the `?` operator and `try` blocks: https://rust-lang.github.io/rfcs/0243-trait-based-exception-handling.html https://rust-lang.github.io/rfcs/0243-trait-based-exception-... (Okay, technically `?` was proposed one month previously.) All the various initiatives related to stable ABI are focused on opt-in mechanisms that work like `#[repr(C)]` and `extern "C"`. The only way to interpret these as examples of "brash young project walks back its early stridency as it ages" is if you ignore the project's actual reasoning and design choices in favor of the popular lowest-common-denominator Reddit-comment-level understanding of those choices.

Getting closer and closer to OOP

by jtrueb 1y ago

Getting closer and closer to OOP

diggan 1y ago

At least they're not expanding the standard library for reading emails, yet...

the_mitsuhiko 1y ago
I'm a bit confused by both this comment and the previous one. Fundamentally nothing new is unlocked by this, that wasn't already possible for many years. It's just the ergonomics that got much better through this change.
- BerislavLopac 1y ago
  The second comment refers to Zawinski's Law [0]. [0] https://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski's_Law https://en.wikipedia.org/wiki/Jamie_Zawinski#Zawinski's_Law
  - tialaramex 1y ago
    I can't speak for your parent but I'm aware of Zawinski's Law and I could see that's what the comment was about, but like your parent it's not at all clear to me why, it's a non-sequitur - this is giving Rust a convenient safe way to up cast, that's not anywhere in the ballpark of the sort of "expand to do everything" that Jamie was describing as inevitable. If you say "Ooh, the new kitten is learning how the cat flap works" and I respond "Those who cannot remember the past are condemned to repeat it" and then you respond with confusion that's because my quoting of Santayana is a non-sequitur. I might even agree with his sentiment about the importance of history, but the kitten learning how to use a cat flap isn't anywhere close to what Santayana was talking about so...
    - diggan 1y ago
      My jest wasn't meant to say that Rust is expanding to do everything, but rather the opposite. The comment I replied to somehow seems to believe Rust is becoming more "OOP", so I took it a step further and also referenced a fairly known pitfall for platforms (so doesn't even apply to programming languages, in my mind). In the end, it's a joke with no even a pinch of truth, which seems to have landed flat, that's on me I suppose.
    - capitol_ 1y ago
      Since rust is popular it naturally attracts a counter movement, so some people will grasp at straws in order to say something negative.

GolDDranks 1y ago

Just having features associated with OOP isn't a bad thing. Object upcasting has its uses. It's some of the other stuff that gets OOP its bad rap. Garbage collection, common in many OOP languages, enables having arbitrary object graphs. The programmer doesn't need to think hard about who has a reference to who, and how long these references live. This leads to performance-defeating pointer chasing, and fuzzy, not-well-thought-of object lifetimes, which in turn lead to accidental memory leaks. Additionally, references in major languages are unconditionally mutable. Having long-lived mutable references from arbitrary places makes it hard to track object states. It makes easier to end up in unexpected states, and accidentally violate invariants from subroutine code, which means bugs. Also, class-like functionality conflates data-layout, privacy/encapsulation, API, namespacing and method dispatch into a single thing. Untangling that knot and having control over these features separately might make a better design.

jtrueb 1y ago
I agree this is useful. I also think it isn’t the end of the world to support some semblance of OOP in Rust. If it helps you ship the business logic, sometimes it’s okay to concede some performance or other cost.
- BrainInAJar 1y ago
  "sometimes" is doing a lot of work there. Sometimes it is, but also sometimes it isn't, and Rust at least gives you a choice (you can use Arc all over the place, or if performance is critical you can be more careful about specifying lifetimes)
  - jtrueb 1y ago
    Arc doesn’t give you the choice until this upcasting feature lands in stable.
mightyham 1y ago
You make some really good criticisms of OOP language design. I take issue with the part about garbage collecting, as I don't think your points apply well to tracing garbage collectors. In practice, the only way to have "memory leaks" is to keep strong references to objects that aren't being used, which is a form of logic bug that can happen in just about any language. Also good API design can largely alleviate handling of external resources with clear lifetimes (files, db connections, etc), and almost any decent OOP languages will have a concept of finalizers to ensure that the resources aren't leaked.

__s 1y ago

Do you consider Go OOP?

dullcrisp 1y ago

I love how OOP is considered a slur on here. It’s no wonder Alan Kay doesn’t come back.

Rexxar 1y ago
Why do you interpret this comment as anti-OOP ? I see it has criticising rust choice to not do OOP at the beginning to finally do it piece by price and that it would have probably be better for the language to embrace it from start.
- dullcrisp 1y ago
  I don’t know how to interpret the comment, but that seems to be how the other responses interpret it.
bfrog 1y ago
Inherit is the first step to tell.
- dullcrisp 1y ago
  I don’t disagree about inheritance.

Xeoncross 1y ago

Are we talking about functional OOP or class-less OOP or JavaScript's prototypal version of inheritance in OOP or Javas functions-are-evil OOP or some other version of OOP? Object-Oriented Programming is a spectrum with varying degrees of abuse.

bigstrat2003 1y ago

OOP is a good thing, not a bad thing. It enables you to use objects to represent relationships easily in a way that other paradigms don't. I agree that the trendiness of OOP was stupid (it isn't the right approach to every situation and it was never going to solve all our problems), but the way it's trendy to hate on OOP now is equally stupid. It's a good tool that sometimes makes sense and sometimes doesn't, not a savior or a devil.

vlovich123 1y ago
“Inheritance” of interfaces good *. Inheritance of stateful objects bad - composition is much better. The OOP model that Rust supports only supports the good kind of OOP and doesn’t support the bad kind. * technically rust doesn’t have interface inheritance but you can treat it that way and it’ll mostly look like that in an abstract sense.
- jandrewrogers 1y ago
  I agree that composition is much better than inheritance for most typical code cases. However, there are cases where inheritance is absolutely the correct model and not having inheritance makes for worse code. I may not use inheritance very often (it rarely makes sense in a systems context) but it is nice to have it when it is unambiguously the right tool for the job. Most code paradigms exist because there is some code context where they are nearly ideal. Someone invented them to handle that case efficiently and elegantly. If you write diverse software long enough you will come across all of those contexts in real code. I’m the opposite of a model purist. I have a strong preference for a languages that let you efficiently switch models on a very granular basis as may be useful in the moment.
- zozbot234 1y ago
  > The OOP model that Rust supports only supports the good kind of OOP and doesn’t support the bad kind. Well, almost. You can actually express "the bad kind of OOP" (i.e. implementation inheritance) in Rust quite elegantly via the generic typestate pattern! But that's still good, because it reveals the inherent complexity of your 'inheritance hierarchy' very clearly by modeling every part of it as a separate, possibly generic type. Hence why it's very rarely used in Rust, with interface inheritance being preferred instead. It mostly gets used in cases where the improved static checking made possible by the "typestate" pattern can be helpful, which has little to do with "OOP" design as generally understood.

echelon 1y ago

Rust has had significant OOP features since the beginning. Trait methods, dynamic dispatch, inheritance, bounds, etc.

quotemstr 1y ago

There's this dynamic in the industry in which a brash young project comes out swinging against some established technique and commits early to its opposite. Then, as the project matures, its authors begin to understand why the old ways were the way they were and slowly walk back their early stridency --- usually without admitting they're doing it. Consider Linux. Time was, metaprogramming was BAD, C was all you needed, we didn't need dynamic CPU schedulers, we didn't need multiple LSMs, and we sure as hell didn't need ABI stability. Now we have forms of all of these things (for the last, see CO-RE), because as it turns out, they're actually good. In Python, well, turns out multiprocessing isn't all you need, and a free-threaded Python has transitioned from impossible and unwanted to exciting and imminent. In transfer encodings, "front end" people thought that JSON was all you needed. Schemas? Binary encodings? Versioning? References? All for those loser XML weenies. Well, who's the weenie now? And in Rust? Well, let's see. Turns out monomorphization isn't all you need. Turns out that it is, in fact, occasionally useful to unify an object and its behavior in a runtime-polymorphic way. I expect yeet_expr to go through eventually too. Others are trying to stabilize (i.e. ossify) the notionally unstable ABI, just like they did to poor C++, which is now stuck with runtime pessimization because somebody is too lazy to recompile a binary from 2010. As surely as water will wet and fire will burn, the gods of Java with stupidity and complexity return.

Rusky 1y ago
> And in Rust? Well, let's see. Turns out monomorphization isn't all you need. Turns out that it is, in fact, occasionally useful to unify an object and its behavior in a runtime-polymorphic way. I expect yeet_expr to go through eventually too. Others are trying to stabilize (i.e. ossify) the notionally unstable ABI, just like they did to poor C++, which is now stuck with runtime pessimization because somebody is too lazy to recompile a binary from 2010. Not to make an argument either way on your general point, but these are really bad examples for Rust if you look at the specifics: Monomorphization was never the only option. Trait objects and vtables predate the RFC process itself. Early Rust wanted more dynamic dispatch than it eventually wound up with. The idea of a "throw"-like operator was introduced at the same time as the `?` operator and `try` blocks: https://rust-lang.github.io/rfcs/0243-trait-based-exception-handling.html https://rust-lang.github.io/rfcs/0243-trait-based-exception-... (Okay, technically `?` was proposed one month previously.) All the various initiatives related to stable ABI are focused on opt-in mechanisms that work like `#[repr(C)]` and `extern "C"`. The only way to interpret these as examples of "brash young project walks back its early stridency as it ages" is if you ignore the project's actual reasoning and design choices in favor of the popular lowest-common-denominator Reddit-comment-level understanding of those choices.