3 ms·

There is no spiral. C's pointer declaration syntax is arguably backwards ("declaration follows usage") but fundamentally follows normal precedence rules. The so

There is no spiral. C's pointer declaration syntax is arguably backwards ("declaration follows usage") but fundamentally follows normal precedence rules. The so-called spiral is total nonsense misinformation.

saagarjha 7y ago
What about this do you find disagreeable? http://c-faq.com/decl/spiral.anderson.html http://c-faq.com/decl/spiral.anderson.html
- dnautics 7y ago
  The fact that it's wrong if you try to generalize it beyond the examples given?
  - saagarjha 7y ago
    Does it? Here's one that I grabbed from cdecl.org: char * const (*(* const bar)[5])(int ) And its translation: declare bar as const pointer to array 5 of pointer to function (int) returning const pointer to char This seems like what I'd get from the spiral technique.
- palotasb 7y ago
  The spiral rule works if "pointer to" and "function returning"/"array of" alternate but it breaks if they don't, i.e., if you have arrays of arrays or pointers to pointers. int** arr1_of_arr2_of_arr3_of_ptr_to_ptr_to_int[1][2][3] In this case, spiraling between [1], ×, [2], ×, [3], int is obviously wrong, the correct reading order is [1], [2], [3], ×, ×, int. (Edit: read × = *) The Right-Left Rule is quoted less frequently on HN but it's a correct algorithm for deciphering C types: http://cseweb.ucsd.edu/~ricko/rt_lt.rule.html http://cseweb.ucsd.edu/~ricko/rt_lt.rule.html
  - diegoperini 7y ago
    I would name that algorithm "inside-out" instead of "right-left" if my understanding of its behavior is correct.
  - saagarjha 7y ago
    Aren't you supposed to treat multiple array or pointers as a group?
dnautics 7y ago
That's exactly my point. It's confusing enough that someone e made a bullshit claim that was totally wrong and confused noobs for years. That won't happen with zig.
- pjmlp 7y ago
  That won't happen with any sane systems language all the way back to Algol dialects. The only thing that C has taken from Algol, was structured control and data.

saagarjha 7y ago

What about this do you find disagreeable? http://c-faq.com/decl/spiral.anderson.html http://c-faq.com/decl/spiral.anderson.html

dnautics 7y ago
The fact that it's wrong if you try to generalize it beyond the examples given?
- saagarjha 7y ago
  Does it? Here's one that I grabbed from cdecl.org: char * const (*(* const bar)[5])(int ) And its translation: declare bar as const pointer to array 5 of pointer to function (int) returning const pointer to char This seems like what I'd get from the spiral technique.
palotasb 7y ago
The spiral rule works if "pointer to" and "function returning"/"array of" alternate but it breaks if they don't, i.e., if you have arrays of arrays or pointers to pointers. int** arr1_of_arr2_of_arr3_of_ptr_to_ptr_to_int[1][2][3] In this case, spiraling between [1], ×, [2], ×, [3], int is obviously wrong, the correct reading order is [1], [2], [3], ×, ×, int. (Edit: read × = *) The Right-Left Rule is quoted less frequently on HN but it's a correct algorithm for deciphering C types: http://cseweb.ucsd.edu/~ricko/rt_lt.rule.html http://cseweb.ucsd.edu/~ricko/rt_lt.rule.html
- diegoperini 7y ago
  I would name that algorithm "inside-out" instead of "right-left" if my understanding of its behavior is correct.
- saagarjha 7y ago
  Aren't you supposed to treat multiple array or pointers as a group?

dnautics 7y ago

That's exactly my point. It's confusing enough that someone e made a bullshit claim that was totally wrong and confused noobs for years. That won't happen with zig.

pjmlp 7y ago
That won't happen with any sane systems language all the way back to Algol dialects. The only thing that C has taken from Algol, was structured control and data.