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But in reality is of limited utility. This fixes the size of the array in the function signature. If I want to write a function that returns the sum of all the

But in reality is of limited utility. This fixes the size of the array in the function signature. If I want to write a function that returns the sum of all the integers in an array I would need to write a new function for each size of array, a non-starter. The annoying thing about this is that the array is just sitting there on the stack of the calling function. The size is completely known at compile time. But it gets thrown away as soon as you call a function.

a_nop 3y ago
Supplying the array length to such a summing function is not a big deal. The compiler is not likely to handle this poorly. Probably gets inlined. If the syntax is the problem, yeah, if you want first class data structures you might not like C.
- chongli 3y ago
  you might not like C The title of the article is “C’s biggest mistake.” If you’re going to rebut the article, do so. Otherwise your reply just comes off as “this is the way it is, deal with it!” which is a pretty shallow dismissal.
tialaramex 3y ago
> This fixes the size of the array in the function signature That's what an array is. Fixed size. If we want to talk about a slice of some runtime determined amount of a thing then we need fat pointers, and C doesn't provide any fat pointer types so it's not a surprise to find it can't do slices.
- chongli 3y ago
  No, I am not talking about a runtime-allocated structure. I’m talking about a function that can accept and operate on arrays of different sizes, all of which are fixed size at their declaration site, and all stored on the stack. There is no reason this shouldn’t be possible. It should not require fat pointers at all because the size information is known at compile time.
  - School-Cotton 3y ago
    AFAICT you’d either have to pass the length at runtime somehow, or treat the function as a generic/template and generate a separate version for each separate N it’s called with. The latter would be pretty far from the ethos of C, imo.
    - chongli 3y ago
      This could be done by storing the length of the array before the first element. It wouldn’t even need to be done in all cases, only if the length is actually used.
    - usefulcat 3y ago
      > AFAICT you’d either have to pass the length at runtime somehow This is exactly the solution proposed in TFA..

a_nop 3y ago

Supplying the array length to such a summing function is not a big deal. The compiler is not likely to handle this poorly. Probably gets inlined. If the syntax is the problem, yeah, if you want first class data structures you might not like C.

chongli 3y ago
you might not like C The title of the article is “C’s biggest mistake.” If you’re going to rebut the article, do so. Otherwise your reply just comes off as “this is the way it is, deal with it!” which is a pretty shallow dismissal.

tialaramex 3y ago

> This fixes the size of the array in the function signature That's what an array is. Fixed size. If we want to talk about a slice of some runtime determined amount of a thing then we need fat pointers, and C doesn't provide any fat pointer types so it's not a surprise to find it can't do slices.

chongli 3y ago
No, I am not talking about a runtime-allocated structure. I’m talking about a function that can accept and operate on arrays of different sizes, all of which are fixed size at their declaration site, and all stored on the stack. There is no reason this shouldn’t be possible. It should not require fat pointers at all because the size information is known at compile time.
- School-Cotton 3y ago
  AFAICT you’d either have to pass the length at runtime somehow, or treat the function as a generic/template and generate a separate version for each separate N it’s called with. The latter would be pretty far from the ethos of C, imo.
  - chongli 3y ago
    This could be done by storing the length of the array before the first element. It wouldn’t even need to be done in all cases, only if the length is actually used.
  - usefulcat 3y ago
    > AFAICT you’d either have to pass the length at runtime somehow This is exactly the solution proposed in TFA..