/* oop.c - an experiment in object-oriented programming in C */
/* Jon Mayo - PUBLIC DOMAIN - October 16, 2006 */
/* techniques taken from:
 * X Intrinsics Toolkit.
 * Object Oriented Programming with ANSI-C, Axel-Tobias Schreiner.
 *  http://www.cs.rit.edu/~ats/books/index.html
 * The Xt Intrinsics as a General Purpose Application Development Platform
 *  http://www.thinkbank.com/jordan/papers/USENIX/AppDev.html
 */

#include <stdlib.h>
#include <stdarg.h>
#include <stdio.h>

#define MAKE_BASECLASS(c) /* TODO */
#define GET_PARENT_CLASS(o) /* TODO */


#if 1
/* enable magic */
#define USE_MAGIC(x) x
#else
/* disable magic */
#define USE_MAGIC(x) 
#endif

struct base_object;
struct base_class;

/*** hidden stuff ***/
struct base_class {
    USE_MAGIC(unsigned magic);
    struct base_object *(*ctor)(struct base_object *, va_list ap);
    void (*dtor)(struct base_object *);
    size_t instance_size;
};

struct base_object {
    const struct base_class *parent_class; /* IMMUTABLE */
};

/*** exported interface ***/

/* allocate a new instance of a particular class */
void *newObject(struct base_class *the_class, ...) {
    struct base_object *ret;
    ret=calloc(1, the_class->instance_size); /* default is to be all zeros */
    if(!ret) return 0;
    ret->parent_class=the_class;
    if(the_class->ctor) {
        va_list ap;
        va_start(ap, the_class);
        ret=the_class->ctor(ret, ap);
        va_end(ap);
    }
}

void deleteObject(struct base_object *the_object) {
    const struct base_class *parent_class=the_object->parent_class;
    if(the_object && parent_class && parent_class->dtor) {
        parent_class->dtor(the_object);
    }
    free(the_object);
}

size_t sizeofObject(struct base_object *the_object) {
    return the_object && the_object->parent_class ? the_object->parent_class->instance_size : 0;
}

/* call the compare interface */
int cmpObject(void *a, void *b) {
    /* TODO: can I really make a place-holder interface with this technique? */
}

/* duplicate an existing object */
void *dupObject(void *the_object) {
}

/* sets a value, returning the original one */
void *setObject(void *the_object, int offset, void *value) {
    /* this is a raw interface, deallocation would be handled by the caller */
}

/* gets the current value */
void *getObject(void *the_object, int offset) {
}

#ifdef STAND_ALONE
int main() {
    return 0;
}
#endif