I lived in a perfect OOP bubble for my entire life. Everything was peaceful and it worked perfectly. When I wanted to move that player, I do player.move(10.0, 0.0); When I want to collect a coin, I go GameMan -> collect_coin(); And when I really need a global method, so be it. I love my C++, I love my python and yes, I also love my GDScript (Godot Game Engine). They all work with classes and objects and it all works perfectly for me.

But oh no! I wanted to learn Rust recently and I really liked how values are non-mutable by defualt and such, but it doesn’t have classes!? What’s going on? How do you even move a player? Do you just HAVE to have a global method for everything? like move_player(); rotate_player(); player_collect_coin(); But no! Even worse! How do you even know which player is meant? Do you just HAVE to pass the player (which is a struct probably) like this? move(player); rotate(player); collect_coin(player, coin); I do not want to live in a world where everything has to be global! I want my data to be organized and to be able to call my methods WHERE I need them, not where they just lie there, waiting to be used in the global scope.

So please, dear C, Rust and… other non OOP language users! Tell me, what makes you stay with these languages? And what is that coding style even called? Is that the “pure functional style” I heard about some time?

Also what text editor do you use (non judgemental)? Vim user here

  • magic_lobster_party
    9•3 months ago

    I don’t program in Rust, but IMO non-mutable by default is how it should’ve always been. It’s more reasonable to make values mutable out of necessity - not make them constants just because you can. Even in OOP I think you should avoid using variables when possible, as they commonly give rise to logical errors.

    I think it’s harder to reason around programs that heavily use variables. It’s easy to tangle yourself into a mess of spaghetti code. You need to read back and forth to understand all the possible states the program can be in and ensure none of these states will break it. “Oh, you can’t call this method on line 50 because some other method call on line 40 changed some internal value, which isn’t corrected until line 60”.

    Same code without variables is usually easier to read. There’s only one state to consider. You just read the code from top to bottom and that’s it. Once a value is set, then that’s final. No surprise states.

    Variables also tend to make multithreading more difficult to reason about.

    Your example with player movement is one example where variables are needed. You should keep using mutables here.

    I think all programmers should learn to program in a more functional style. Even if you end up using OOP you can still make use of functional programming practices, like avoiding variables.