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

  • @loafty_loafey
    23•8 months ago

    Late response and you might have already gotten an answer, but what you wrote is exactly the same as:

    // Define our player struct 
struct Player {
     x: f32,
     y: f32,
     rotation: f32
}
// Define the methods available to the player struct 
impl Player {
     pub fn move(&mut self, x: f32, y: f32) {
          self.x += x;
          self.y += y;
     }

     pub fn rotate(&mut self, by: f32) {
           self.rotation += by;
     }
}

fn main() {
    let mut player = Player { x: 0.0, y: 0.0, rotation: 0.0 };
    player.move(10.0, 10.0);
    player.rotation(180.0);
}

    The code example you wrote does not use anything that is exclusive to OOP languages as you are simply encapsulating values in a class (struct in the Rust case).

    Unlike C++, the biggest difference you will find is that Rust does not have the same kind of inheritance. In Rust you can only inherit from traits (think interfaces in Java/C# or type classes if you have ever used Haskell), whereas in C++ and other OOP languages you can also inherit from other classes. In a lot of cases just using traits will suffice when you need inheritance. :)

    So in conclusion, no global functions! You still have the same name spacing and scoping as you would in C++ etc!

    Ps. I use VScode because it rocks with Rust, and while Rust is heavily inspired by functional programming languages, it is not a pure functional programming language (nor is C) but that is another can of worms.