Feature request: define user numerical types with their arithmetic operators about cake

[thradams]

obs:
C23 also added _BitInt(N) and _Decimal32, _Decimal64, and _Decimal128.
C99 has complex.

Converting any of these types to C89 would require a review in expressions
and this work could be reused for operators overloading.

[thradams]

One alternative is to convert expressions using operators to function call syntax.
For instance the expression

a + b * c

becomes

add(a , mult(b, c));

the names add,mult etc can be modified according with the types, for
instance, using struct tag.

Having that the programmer just provide the function implementation.
It also can be a function like macro. With _Generic the same name add etc can
be preserved.

[cblc]

Yes, I did that in my code. And my code became a nightmare to understand. So, what I'm saying is a feature in Cake which would do the conversion for you, so that you don't need to make your code unreadable.

[thradams]

C23 included the header <stdckdint.h>

bool ckd_add(type1 *result, type2 a, type3 b);
bool ckd_sub(type1 *result, type2 a, type3 b);
bool ckd_mul(type1 *result, type2 a, type3 b);

Maybe cake could automatic convert from expression syntax inside _safe_check( )
to a function adding the checks.

int main() {
  int r = _safe_check(a + b *c);
  if (errno != 0) printf("oops");
}

/*generated function*/
static int _expression_1(int a, int b, int c) {
  int r;
  if (ckd_mul(&r, b, c) != 0) errno = 1;
  if (ckd_add(&r, a,  r) != 0) errno = 1;
  return r;
}

int main() {
  int r = _expression_1(a, b, c);
  if (errno != 0) printf("oops");
}

[cblc]

I don't know that header yet. But I think that all the operators that can operate on integers and floating point types would be potentially necessary. Maybe even unary operators.

The purpose would be to let the client program implement its own integer and floating point types.

[cblc]

Indeed, I feel that every C compiler should have offered this feature for years now, because it's really useful.

[cblc]

Is there a place in the Cake source code where I could just modify the AST replacing every operator occurrence by a function invocation taking one or two arguments depending on whether the operator is unary or binary? (I left at a side the tertiary conditional operator because I don't think it makes sense to overload it: the only interest would be in inner expressions with other operators inside the tertiary operator, but not in the tertiary operator itself).