The ACE superset

ace.c

#ifndef __ACE__
#error ACE is required to compile this unit
#endif

// Line comments are allowed!

// Defines symbols to make code more readable
#include <ace.h>

#include <string.h>
#include <stdio.h>

// 'class' expands to '_Class'
class object {
	// 'virtual' expands to '_Virtual'
	// the this argument is left out
	virtual void tostring(FILE *f);
};

// implement object.tostring
// 'member' expands to '_Member'
// _Member is used to avoid name collisions
member void tostring(class object *const this, FILE *f)
{
	f.printf("class object");
}

// 'extends' expands to '_Extends'
class derived extends object {
	// 'override' expands to '_Override'
	// it requires a seperate tostring for class derived
	// than the one that's already defined for class object
	// the this argument is left out
	override void tostring(FILE *f);

	// regular structure fields
	// every field is public
	// methods can be made private by making them static,
	// and only declaring them within the class implementation unit
	int a, b;
};

member void tostring(class derived *const this, FILE *f)
{
	f.printf("{ a: %d, b: %d }", this->a, this->b);
}


// constructor implementation
member void init(class derived *const this, int a, int b)
{
	this->a = a;
	this->b = a;
}

int main(void)
{
	class derived d;
	d.init(10, 20);
	class object *o = &d;

	o->tostring(stdout); // prints '{ a: 10, b: 20 }'
	stdout.printf("\n"); // printf _Member function
	d.tostring(stdout);  // prints '{ a: 10, b: 20 }'
	stdout.fprintf("\n"); // fprintf non-_Member function
	                      // equivalent to fprintf(stdout, "\n");

	return 0;
}