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If Inheritance is so bad, why does everyone use it?

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Re: If Inheritance is so bad, why does everyone use it?

#71

Post by mrkeen »

bluetomcat wrote: post #69
captainmuon wrote: post #39

I feel people don't understand what inheritance and (object orientation in general) is useful for, misuse it, and then it gets a bad reputation. It's not about making nice hierarchies of Cars, Fruits, and Ovals. For me the main point is (runtime) polymorphism. E.g. you have a function that takes a general type, and you can pass multiple specific types and it will do the right thing. And if you want to avoid huge if-e…

Polymorphism is doable in plain old C with lookup tables and function pointers. If that is the only benefit, what is the point of creating a language where everything is an object?

> Polymorphism is doable in plain old C with lookup tables and function pointers

Not without casting. qsort is still:

    void qsort_r(void *base, size_t nmemb, size_t size,
                 int (*compar)(const void *, const void *, void *),
                 void *arg);

Re: If Inheritance is so bad, why does everyone use it?

#72

Post by jonathanstrange »

I prefer languages with full OOP, ideally with multiple dynamic dispatch. What I'm not fond of are languages like Java that overuse OOP design patterns, force you into them, or require lots of OOP boilerplate. If you have a class whose sole instance serves as a factory for other objects, you know you're on the wrong path. But I've never seen any coherent and sound arguments against OOP in general. Nobody forces you to use it, and, for example, it would be much easier to develop and deal with GUI frameworks in Go if it had classes with inheritance. As a rule of thumb, if for some reason your language drives you to emulate dynamic dispatch with explicit type switches on one or even multiple arguments, then it probably should have inheritance and dynamic method dispatch.

Re: If Inheritance is so bad, why does everyone use it?

#73

Post by mrkeen »

captainmuon wrote: post #39

I feel people don't understand what inheritance and (object orientation in general) is useful for, misuse it, and then it gets a bad reputation. It's not about making nice hierarchies of Cars, Fruits, and Ovals. For me the main point is (runtime) polymorphism. E.g. you have a function that takes a general type, and you can pass multiple specific types and it will do the right thing. And if you want to avoid huge if-e…

> For me the main point is (runtime) polymorphism. E.g. you have a function that takes a general type, and you can pass multiple specific types and it will do the right thing.

The runtime part is what I dislike. If I have a fruit which is an apple or a banana, I can't pass that to a method expecting an apple or banana. It can only be passed as a fruit.

> And if you want to avoid huge if-else statements, you should put the code for the special cases in the classes, not in each function that operates on them.

This is common OO wisdom that I strongly disagree with. For example, in my program I have a few types (Application, Abstraction, Variable, etc.), and a lot of transformations to perform on those types (TypeCheck, AnfConvert, ClosureConvert, LambdaLift, etc.).

I prefer to have all the type-checking code inside the TypeCheck module, and all the closure-converting code inside the ClosureConvert module. I'd take the "huge if-else" statements inside TypeCheck rather than scatter typechecking across all my datatypes.

Re: If Inheritance is so bad, why does everyone use it?

#74

Post by thiht »

bigstrat2003 wrote: post #28

I don't think inheritance is bad at all. It is very often the easiest way by far to model a problem. Sure, it's not perfect, but I think it is wildly overhated by a vocal minority.

I think that’s just what you’re used to. Since I switched from Java to Go 7 years ago, I don’t think I’ve missed inheritance a single time. I haven’t needed to model anything with inheritance once. There are definitely things I’ve missed from Java, but not inheritance.

Re: If Inheritance is so bad, why does everyone use it?

#75

Post by mrkeen »

jonathanstrange wrote: post #72

I prefer languages with full OOP, ideally with multiple dynamic dispatch. What I'm not fond of are languages like Java that overuse OOP design patterns, force you into them, or require lots of OOP boilerplate. If you have a class whose sole instance serves as a factory for other objects, you know you're on the wrong path. But I've never seen any coherent and sound arguments against OOP in general. Nobody forces you t…

> But I've never seen any coherent and sound arguments against OOP in general.

How about arguments for OOP? Especially for things which can't be done better elsewhere.

Re: If Inheritance is so bad, why does everyone use it?

#76

Post by bl4ckm0r3 »

xwolfi wrote: post #50
cess11 wrote: post #26

Earlier quoted context omitted.

I disagree. Starting with separating class and object have never been helpful when I've tried to teach computer programming, while functions seems to have been more intuitive to those people. After a while you get to closures, which are pretty much objects without classes, and then factory functions that produce closures and there you have something like a class as well. If I were to design a course I'd probably foll…

But you go from the bottom up here, I don't like to describe it that way. I prefer to say that we naturally classify objects around us using fuzzy boundaries like "a house", "a cat", which don't exactly mean anything: they are templates we use later to actually generate an actual house, or an actual cat (on a piece of paper as a drawing for instance). The world being separated between our internal classes and the int…

I think you identified the selling point of OOP, it's easy to reason about it and logically it makes sense to human because we do think in terms of objects (the user, the order, the item etcetc) and responsibility segregation (User->login(), Order->fulfil(), etc). To your example of just launching intellij and using java (or ruby or whatever) to build something, yeah it works and it works fast and it's easy to add new features, and it's also easy to end up with a >3k loc User class in python that no one can touch (true story).

Re: If Inheritance is so bad, why does everyone use it?

#77

Post by poisonborz »

My take is that after something becomes sufficiently popular and mainstream, for a lot of people who want to be seen as innovative, the only way is to lash out against it. See all the articles on how hellishly bad agile, php or javascript is. A lot of criticism is valid of course, but that is irrelevant in the larger scheme of things - there is a reason they became what they are today.

Re: If Inheritance is so bad, why does everyone use it?

#78

Post by dsego »

bluetomcat wrote: post #53
KorematsuFredt wrote: post #6

Here is my take on it. At one point "Object Oriented" became "Blockchain" (or now Gen AI) of those times. You had to be "object oriented" in order to be taken seriously. This applied to everything. Even finished software products were called "built using object oriented". The esoteric concept of inheritance became popular after that. At some point it became so popular that people figured out that it is not really a g…

In the 1990s, it coincided with the proliferation of GUIs and their respective programming interfaces. Most frameworks use hierarchies like Object->View->Control->Button->ImageButton. Then people decided that this is the way for modeling abstract problems that don't have to deal with visual or real-world entities whatsoever.

And you would get nice automatic completion when doing object name, dot, and waiting for the IDE to list all possible methods. This was exploratory programming, the copilot of its time.

Re: If Inheritance is so bad, why does everyone use it?

#79

Post by ehnto »

cryptos wrote: post #59

My impression is that inheritance is in many common programming languages the easiest way to share code. Sharing code in another way would require some more thoughts and sometimes code, so the lazy programmer takes inheritance. Traits as a general concept would be very useful in many programming languages, but only some (like Scala) have proper support for it. In principle a Java interface with default methods (imple…

Traits and contracts or interfaces, but even still inheritance has it's merits. Being fast and easy is a benefit, and I find defensive programming in extensible systems can benefit from a foundation of expecting inheritance.

Re: If Inheritance is so bad, why does everyone use it?

#80

Post by EPWN3D »

It seems like protocols solve 90% of the problems that inheritance does, but with 10% of the headaches. Instead of trying to ensure that two types can both be passed to a function that only knows about the parent type, just have a parameter that says "Whatever's passed has to conform to this, I don't care what it is otherwise."
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