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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?

#161

Post by tootie »

d_burfoot wrote: post #122

It seems like there's a huge industry of people critiquing Java and OOP but misdiagnosing the problems as technical rather than sociological. The immense pain and suffering that is related to Java and its ecosystem is because of the terrible organizational conditions that tend to co-occur with usage of Java. Big slow companies, long boring meetings, arguments about design patterns, "architects" who haven't written co…

I have often observed that Java is great because it solves organizational problems. Strong and static types, interfaces and most of all, javadoc, were miraculous for conveying intent to integrators and maintainers. Even seemingly insignificant things like a naming convention for packages was extremely useful. A lot of the features trumpeted in Java when it was new, like abstract classes or checked exceptions, were adopted religiously at first but fell out of favor a long time ago. Interfaces and interface inheritance is extremely useful.

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

#162

Post by maleldil »

ruszki wrote: post #147
ben7799 wrote: post #107

I love the way people take their narrow range of experience and over generalize it to everything. Bonus points for having a blog or maybe a patreon to tell everyone how it really is. We have a million flavors of the month but in the end it doesn't really matter. Pick a flavor and there will be teams that are successful and teams that are not. No silver bullet will make the non-successful teams magically turn into suc…

> "I/We failed with " never generalizes to " " is bad. I thought the same for decades, then I met Groovy and Grails. Of course, it’s not bad in an absolute sense (IMHO that doesn’t make any sense), but when some problem can be found only at runtime, when any proper compiler would catch that compile time, it’s hard to argue that it’s a good direction. Especially when TypeScript made it quite obvious what’s possible on…

> TypeScript made it quite obvious what’s possible only with simple type checking.

Typescript's type system is anything but simple.

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

#163

Post by tootie »

ldjkfkdsjnv wrote: post #131
d_burfoot wrote: post #122

It seems like there's a huge industry of people critiquing Java and OOP but misdiagnosing the problems as technical rather than sociological. The immense pain and suffering that is related to Java and its ecosystem is because of the terrible organizational conditions that tend to co-occur with usage of Java. Big slow companies, long boring meetings, arguments about design patterns, "architects" who haven't written co…

Java complexity is also an artifact of Java being used in large complex systems. People are really complaining about how hard programming is. There are many types of large scale systems where I would only code it using the JVM, everything else is a nightmare. Big tech companies largely feel the same

There is an all-time great quote from Bjarne Stroustroup when asked about how many people hated C++

> There are two types of programming languages: The ones people complain about and the ones nobody uses.

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

#164

Post by vidarh »

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?

Because syntactic sugar and abstractions matter. You can do everything in assembly too, yet we prefer something higher level.

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

#165

Post by shawn_w »

slaymaker1907 wrote: post #153

For a really neat implementation of OOP and inheritance, I would recommend checking out Racket's class system (not to be confused with generics). It mostly solves the multiple inheritance problem by mixins and also has a great interface system.

I find Racket's OO stuff to be awkward and cumbersome to use, and rarely a good option. One of these days I'm going to port a CLOS-inspired Scheme OO system like Guile's GOOPS to Racket...

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

#166

Post by cogman10 »

caseysoftware wrote: post #156

The key is "prefer composition to inheritance" and dates back to Gang of Four. The word "prefer" is critical to understand. It just means "usually choose A over B" not "B is never the right answer." Unfortunately, since we - as an industry - like hard and fast rules, we move towards that second explanation and act like inheritance never makes sense. Like any tool, there's a time and place where it is the best tool, o…

I agree with this sentiment but I also must say that the time's I've needed inheritance have been few and far between. I have seen really good examples where it works really well (UX is pretty common, but I've also seen really clean cases like data structures with complex interfaces and a simple abstract class).

Where I think inheritance works best is when the state in base classes is limited and the interface is quiet clear. Ideally where you are meant to override is also well defined.

Where it's the worst is when someone tries to use inheritance because they notice coincidentally duplicate code. The worst hell for this is in application configuration. I've seen 5 layer deep inheritance trees to handle really basic things like "what port should this app bind to". It saved no code and introduced a bunch of complication around the transitive dependency baggage it brought on board.

IMO, configuration should always be done via composition. It's more than fine to have a bunch of smaller composable config pieces just so long as you can easily jettison the broken parts.

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

#167

Post by shagmin »

EPWN3D wrote: post #80

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."

I'm guessing the closest equivalent in languages like Java or C# are interfaces, right? Underutilized IMO.

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

#168

Post by david2ndaccount »

layer8 wrote: post #146
EPWN3D wrote: post #80

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."

“Protocols” is Apple-specific (or Objective-C/Swift-specific) terminology. They correspond to types 1 and 2 of inheritance that TFA mentions.

Python also has protocols: https://typing.readthedocs.io/en/latest/spec/protocol.html#p...

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

#169

Post by josephg »

turnsout wrote: post #150

I stopped using inheritance when Swift protocols and TypeScript interfaces came along. Although it sometimes means you need to do nasty things with generics, it beats the fragility of inheritance. With ObjC, I eventually came to hate updating superclasses, because I knew it would lead to unexpected behavior in subclasses.

I had the same experience. I’m a few years into using rust now - which doesn’t implement inheritance at all and I don’t miss it. In typescript I barely use classes at all. I prefer an interface paired with a constructor function.

I think it’s almost always better to first think of data as a struct, with associated code that acts on that struct. As the old saying goes, show me your data structures and not your code, and you don’t need to show me your code.

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