extensions.c

// Copyright (C) 2023 dasshiva
#include <stdlib.h>

// Compiles on GCC 11.4.0 ubuntu idk about other systems
// Abusing macros to make C look a tiny bit better (maybe worse for some)
#define class(x, contents) typedef struct x x; struct x contents; // declare a class x
#define var(ty, name) ty name; // declare a variable
#define func(ty, x, ...) ty (*##x) (__VA_ARGS__); // declare a member function maybe static or non-static
#define static_func_def(ty, x, ...) ty x (__VA_ARGS__) // declare a static function
#define func_defnp(class, ty, x) ty x (class* self)  // define a non-static function taking no parameters
#define func_def(class, ty, x, ...) ty x (class* self, __VA_ARGS__) // define a non-static function taking parameters
#define new(class, ...) class* new_##class(__VA_ARGS__) // define the class's constructor always called new_<class-name>

class(system, {
  var(int, hi) 
  var(int, hey)
  func(void, function)
})

func_defnp(system, int, function) {
    return 0;
}

new(system, user_input) {
    system* p = malloc(sizeof(system));
    p->function = function;
    p->hey = 0;
    p->hi = user_input;
    return p;
}