[NO REPLY] Any type as a class (rev #2, 2018-1-15)

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[NO REPLY] Any type as a class (rev #2, 2018-1-15)

Postby Giovanni » Wed Dec 13, 2017 10:50 am

Another idea is to make this language support some concepts of object programming without going into complexities. One possible solution is to introduce polymorphism using structures. The proposed syntax is pure fantasy, it could be made more elegant.

Basically structure could be extended:

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struct coords2d {
  int x;
  int y;

struct coords3d extends coords2d {
  int z;

Pointers to coords2d and coords3d would be "related" so casting would be possible between them. This solves a common problem in C when you need to have structures that share a common part and you need to do little hacks, see thread lists in ChibiOS for example.

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struct element {
  element *next;
  element *prev;

struct ready_list extends element {

struct thread extends element {

Next step is to associate functions to structures (but also other types), this would mean methods, note the "this" keyword:

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void element:dequeue(void) {
  this->next->prev = this->prev;
  this->prev->next = this->next;

element *el;


void uint32_t:increase(void) {
  this = this + 1;

void uint32_t:clear(void) {
  this = 0;

uint32_t n;

We could also thing to static methods, methods that can be called on the type not an actual type instance.

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void element::reset(void) {


I think there is no need to have a specific class constructs, any type can do simple things like this. Virtual methods could also be considered. Complex things like runtime types checking, I think, would be out of scope.

Types as namespaces for constants

This is a bit Java-like, one of the C problems is that enums have no namespace so conflicts are common. It would be possible to declare constants with type associated to structures or other types this way.

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/* declaration */
const uint8_t element::LINK = 0;
const uint8_t element::UNLINK= 1;
const uint8_t uint8_t::ZERO = 0;
const void * ptr_t::NULL = (void *)0;
const element * element::NULL = (element *)0;

/* use */
uint8_t operation = element:LINK;
uint8_t i = uint8_t:ZERO;

Those constant would:
- Not allocate memory, pretty much like #define as use.
- Have a specified type unlike enums.
- Have a namespace (the type name).


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