And it is not for all people.
But it's just a foreign language; You could look at Japanese text[0] and make similar statements, and would be just as valid (or rather, invalid) as your statement.
You expect to be able to read it because you're used to a class of languages which are all similar enough at the surface level -- perhaps you are even familiar with more than one fundamentally different classes, say, "lispish and algolish" or "germanic and latin". But that doesn't make APLish or Japanese[0] horrible.
This is just APL using C syntax.
[0] assuming, the proverbial you does not know Japanese
Just because you find it strange, it does not mean it's strange.
I'm sure you'd find languages in Papua New Guinea difficult at times, and you'd argue English is "better" because more people speak it, and there is a richer literature in it, but the ideas expressed in those languages - and how they are expressed uniquely in those languages - are valuable to the people who speak them.
I'd be very interested to learn more about which semantics of APL-derivatives correspond to which of the 4 or 5 distinct meanings of the keyword 'static' in C.
It's not in the "k.h" header, though that references it also.
Maybe the build system injects it through the compiler command line or a forced-include header. Though the gcc command line alluded to in the block comment header shows no evidence of that.
Edit: Found it! It's a typedef for a pointer to a struct k0:
typedef struct k0{signed char m,a,t;C u;I r;union{G g;H h;I i;J j;E e;F f;S s;struct k0*k;struct{J n;G G0[1];};};}*K;There are a handful of helper functions to get/set various parts of this structure, and most of the functions in the language (and its implementation) take 1 or 2 of these and return 1.
This code is basically obfuscated by hand. Absolutely unapproachable. Only the original author(s) can understand it.
Judging by other comments, it seems to work well. So they seem to be good programmers producing working code. It's just not intelligible by other human beings, which is a pretty bad thing, but not the only factor in software quality/health.
The Vim code base is at some parts straight batshit insane, but it's one of the most polished programs I've ever used.
All that being said, I would find infuriating to work with such code. Nope!