Why OOP Exists
mathspp.com
mathspp.com
For all these reasons I just skip it. I still use OOP languages, but I leave the OOD at the door.
For what it's worth, you can get all that with plain old C. Declare structs up front. Allocate them all as pointers. The C file is the class, and has the actual definition of the structs.
Strangely enough, in a sense, OOP languages makes it harder to do this than in C. Not that C doesn't have other flaws.
What people forget -- much like the design patterns in the gang of four book -- is that languages and frameworks evolve.
A decorator pattern was a niche but useful abstraction in the 1990s. In Python today you can @decorate stuff just like that. It's evolution.
The same holds for OOP. Encapsulation and co-located methods with the encapsulating slots was an incredibly powerful upgrade over basic structs. Now most languages have first-class functions and lexical scoping so you can build your own encapsulation that way.
It's all good. Just use whatever fits best.
Most complex codebases I've seen which were pure Functional Programming were spaghetti code; unmaintainable.
What I saw every single time was that the project was syncing a huge amount of state in a central place and then passing it through a large number of components and sub-components. The top level component basically had to have full awareness of everything going on inside the system in order to do its job and there were no separation of responsibilities because none of the components had sovereignty over the state they needed to do their job independently. It's just components micro-managing components all the way down.
React with Redux is probably the best FP implementation I've seen thus far but even it is kind of a mess. I have nightmares about Redux Saga. The Redux Saga logo is literally a stylized drawing of entangled spaghetti.
Had Redux + Saga been presented to people as part of React at the time it was introduced, React would probably not have become so popular. Because people would have understood that it creates too much unnecessary baggage which isn't worth it. React was used as a gateway drug to Redux which was itself a gateway drug for Saga! And what I observed in practice is that most React apps are glitchy AF; and those glitches are usually difficult to reproduce and fix, even if you know all the ins and outs of the framework!
to me the best way to design large systems is sort of like an ecs. you don't separate components by state + behaviour, you separate systems and state.
There's a reason why 99% of video games are OOP. That level of complexity is just too much for FP.
the current trend are ecs's which are distinctly not classical oop
What you are describing is OOP. Passing messages between identities over calling pure functions with values.
You know, people have put functioning codebases using pure functional programming languages like Haskell, Elm, Purescript, etc. I really don't see what in your opinion is too close to FP to work.
Most programs code bases of course need some way of doing side effects and not being 100% pure so many haskell projects would not be classed as 100% pure.
"[...] pure functional programming whilst still functioning."
I mean, what is this?
When I read what you are saying here, you are saying that an "advanced codebase", whatever that means, using functional programming leads to centralized state and distributed components. And you know this because the codebase you are thinking about has this software architecture.
I have been in such codebases too, they tend to be frontend and maybe that is just the way you have to do it, maybe not. But this is not a property inherent to functional programming. Solving problems with a component or object concept as a central abstraction for "a thing" is the OOP way. I know this because this is how I spent the first half of my career. You think you need a _substantive_ onto which you perform verbs. Nothing wrong with this though, I am not picking a fight with OOP.
I can offer what I refer to when I talk about FP so that we can at least have a real thing to disagree over :)
1. model the domain and interactions with it with strong types such that neither interactions nor state can represent values outside of the domain.
2. parse, don't validate
3. Use modules, stateless collections of declarations, to organize stateless functions. No this. No self.
4. No magic code. I.e.: no null checks, no magic number checks, no arbitrary logic in four places that together make up the fact that prices can have taxes. Abstract it and "store" these runtime decisions using typed values, use functions that accept these typed values to force use of the aforementioned types.
5. Control the side effects. This does not mean that you have to use Haskell or monads or anything like that. Just that managing it is a good thing.
6. #5 implies keeping track of state. I.e.: no, you may not just willy-nilly read it from the persistent store, cache or file.
Isn't one of the tenants of FP that nothing is mutable anywhere?
But I also spent some time with modern Spring Boot, and I get where the hate is coming from. There is a lot of complexity that just doesn't seem necessary at all.
We're collectively shaking a lot of trees when we build frameworks, languages and tools. What works? What does not? What is the right level of abstraction? How much developer ergonomy do we want to sacrifice?
Sadly we only seem to know in hindsight what works well. But that is also how we learn and grow; it was just meant to be this way.
The point is not to be snug about it. Functional programming (and monads) are actually simpler. You just need to resist the urge to "make it more understandable".
Abstract math doesn't have good analogies to the real world. By trying to make an analogy with the concrete ("monads are mappable") you lose simplicity.
They are supposed to help you build better foundations; the abstractions to better understand your complexity you need to build (or at least pick) yourself.
Good foundations then help you relate the abstractions. For example, the categoric dual of a product is a sum. We can apply it to relation (relational algebra), and we get that sum is data inheritance.
So that gives you understanding of how functions (foreign keys), product (relation) and sum (inheritance) fit together. This sometimes helps to build abstractions in a consistent way.
I'm sure there is some (very high) level of inherent project complexity where the massive number of abstractions and tools that Spring Boot gives you (and forces on you) actually starts turning into a net positive... And I'm also fairly sure that most projects don't quite break even, and would be better off with something more lightweight.
also a lot of oop hate is 1) hatred of compile-time hierarchies attempting to match the domain model and 2) all the complexity in oop systems which isn't really inherent to OOP but made possible by it. oop doesn't require a PrototypeFactoryInjectorFactoryBean but it doesn't prevent you either :)
on the flip side I've seen functional codebases which are also full of complexity because of how fragmented everything is, like 20 functions all applied when it could have been a single imperative one making it hard to keep track of what is happening.
and of course everything in between
I think the hate typically comes from the mis-application of various tools; overly complex solutions for simple problems. There's nothing wrong with patterns per say, or frameworks that have complex building blocks for every conceivable permutation of relatively common issues. However, when people reach for unnecessarily complex tools out of laziness/habit, some hate is justified. I suspect this is very similar to what you're saying, and of course, it's not OOP specific. Functional languages have their patterns too, but instead of a famous book enumerating them, we have a famous blog post stating that functional languages are so awesome that they don't need patterns (or at least, this is how most people seem to interpret it).
Many who've entered the career in the last decade or so seem to have missed what I 'd consider to be quite a fundamental grounding.
Not even advanced concepts from the gang of four book - though I have taught these too - but often just an un-awareness of OOP in general, even simple things like understanding encapsulation.
Frameworks and languages do evolve, but never being taught basic things like encapsulating state or exposing dependencies seems an issue. Very differnt from my own time as a junior when this stuff was constantly hammered home.
I think it's just a shift in how development works: epicycles and all that. Luckily most OOP stuff they need to know can be taught quite quickly. And perhaps not knowing about GoF is a minor win for cyclomatic complexity in your codebase :-)
If you're a Typescript developer doing React you're probably not going to reach for classes, for example, as it's just not a common paradigm in most modern React/TS codebases.
I used to be OOP hater, but realized that it has it's place and some problems are OOP shaped and OOP is a wide range of techniques. I do think that python is a sloppy language and generally don't like it.
Functional programming has it's place and I love it and is probably what my mind goes to the most, but often in Functional languages I find you can 'over fit' to a particular way of doing things, And with OOP your get more degrees of freedom with things you can do with a class and things can be modified easier, think sort of problems like a board game just as an example treating the pieces as an object can make it easier to modify any section of the logic of the game and add new pieces then the typical functional approach.
The "behaviours" being modelled here were data access. Writing .name() instead of .name.
You can save yourself the time of manually packing these structs by writing out a constructor in full. Which the article called "automatic".
(You don't even need to write out the constructor for a struct in C99. Probably any other modern language too)
Yes. And structs are just bytes. Levels of abstractions don't do anything the underlying levels don't already do, they just give you means to express your intent in a clearer form.
And then sometimes it is useful to extend these functionalities for specific special cases.
Maybe OOP is often taught going too abstract. And trying to model wrong things. But thinking of it as grouping fields and then adding functions to manipulate or use those and things related to them is useful.
Rigid class-based inheritance (especially multi-inheritance) is what sucks. This over-engineered complexity really only benefits things like window toolkits where you want super rigid modeling of widget types. But even that's a stretch.
Traits do OOP the right way. Complete flexibility.
Dog goes "woof"
Cat goes "meow"
Bird goes "tweet"
And mouse goes "squeak"
I see it with OOP, XML, design patterns, and other things, now with LLMs. (LLMs - you really want to build complex systems in badly specified natural language, compiled or interpreted with an inscrutable algorithm and possibly indeterministic?)
Is it the excitement from a new analogy? Or are engineers naturally empiricists, while the rationalism/empiricism distinction doesn't work in computer science?
I think we would be better off if we just learned functional programming and few abstract concepts (categories, monads). Simpler than OOP.
The thing that empowers first-class functions and closures (lexical binding) is the exact same method by which encapsulation works, even if the latter opts for heap vs stack. The fundamentals are the same.
Here's a simple one in Emacs Lisp:
(defmacro send (object method &rest args)
"Sends a METHOD to an OBJECT with ARGS."
`(funcall ,object ',method ,@args))
(defun make-animal (name)
;; 'hunger' is entirely private (encapsulated)
(let ((hunger 5))
;; here's our lambda using lexical binding
(lambda (method &rest args)
(cond
((eq method 'get-name) name)
((eq method 'feed)
(setq hunger (max 0 (1- hunger)))
"Yum!")
(t (error "Animal does not understand: %s" method))))))
(let ((good-boy (make-animal "Rex")))
;; "call" (via our macro) the "get-name" method; then feed. hunger does down 1.
(send good-boy get-name)
(send good-boy feed)
;; pretty-print the "object" good-boy
(pp good-boy))
;; this is the state of it after the two calls.
#[(method &rest args)
((cond ((eq method 'get-name) name)
((eq method 'feed) (setq hunger (max 0 (1- hunger))) "Yum!")
(t (error "Animal does not understand: %s" method))))
((hunger . 4) (name . "Rex"))]No, it won't. I'm especially sad that this, like so many OOP guides before it, did not go into how it interacts with data structures and bigger picture stuff. It had the perfect chance to do that as it could have made a Catalog class and then had a discussion about what belongs to that and what to the books. Instead it started to abstract on author, in the stupidest way possible (no, no one will ever look up a book using the author birth date).
It's incredibly difficult now dealing with zoomers in the workplace that think I'm some old boomer that never learned "proper computer science".
No, sorry Timmy, it's not because I don't understand microservices, it's because I actually do.
If what you learned in university was plain wrong that does not sound good because computer science has eternal truths to it, If an architect said everything he learned in university was wrong I would be very worried and not trust his judgement because he should have learned facts not just theories of practice. If he only learned theories of practice I would be worried, if he learned both theories of practice and science and starts to disagree with the science I would be worried.
The problem is a lot of the science might be correct but that doesn't make it pragmatic and more often than not, it's just counter productive.
But the things that are in a computer science course. Type theory, compatibility, time/space complexities, more general algorithmic analysis, Logical programming, logical inference algorithms, Low level fundamentals, Mathematical concepts and proofs, machine learning, different models of programming, combinatorics algorithms. These are very useful many unchanging.
I must concede that I do hold in low esteem theories of practice that are taught as a panacea but this is a tiny fraction of what a student will learn and likely any one learning the craft will simply pick this up from tutorials or youtube.
It's not as if they are always bad rules of thumb either but that they can be done away with or violated once one knows what they are doing and has understood a bit more and got a feel for things.
Other than practicing some leet code in between jobs, it's extremely rare any of that stuff comes up.
The hard parts in my job isn't and hasn't been the computer science parts in a long time, or at least when it does come up it's not something I really think about much. The trade offs are almost always domain, business or product based. The technical solutions are just down stream of those constraints.
Oh, it also helps me to pay my bills, because someone has to untangle the mess.
And it helps my therapist, because he has to keep the madness that grows inside of me in check.
Jokes aside: I was taught OOP at university.
I was also taught functional programming, answer set programming and other forms such as logical programming.
Focus was definitely on OOP though.
I mainly see OOP as a way to (dis) organizer code and a way for hardware manufacturers to sell more hardware.
In reality this seems to make coupling even worse. Now you have to dig 8 classes deep just to find the business logic for a particular feature. Changing it is even harder because the rest of the program expects this part to behave in a very specific way.
I agree with the reality.
I’m not saying you should ever fire a coworker out of a cannon. I’m just saying that I wouldn’t always hold it against you.