undefined | Better HN

story

0 pointsCloudef11mo ago0 comments

To be honest your snippet isn't really C anymore by using a compiler builtin. I'm also annoyed by things like `foo(int N, const char x[N])` which compilation vary wildly between compilers (most ignore them, gcc will actually try to check if the invariants if they are compile time known)

> I haven't really understood the advantage compared to simply running a program at build time.

Since both comptime and runtime code can be mixed, this gives you a lot of safety and control. The comptime in zig emulates the target architecture, this makes things like cross-compilation simply work. For program that generates code, you have to run that generator on the system that's compiling and the generator program itself has to be aware the target it's generating code for.

0 comments

uecker11mo ago

It also works with memcpy from the library: https://godbolt.org/z/Mc6M9dK4M I just didn't feel like burdening godbolt with an inlclude.

I do not understand your criticism of [N]. This gives compiler more information and catches errors. This is a good thing! Who could be annoyed by this: https://godbolt.org/z/EeadKhrE8 (of course, nowadays you could also define a descent span type in C)

The cross-compilation argument has some merit, but not enough to warrant the additional complexity IMHO. Compile-time computation will also have annoying limitations and makes programs more difficult to understand. I feel sorry for everybody who needs to maintain complex compile time code generation. Zig certainly does it better than C++ but still..

CloudefOP11mo ago

> I do not understand your criticism of [N]. This gives compiler more information and catches errors. This is a good thing!

It only does sane thing in GCC, in other compilers it does nothing and since it's very underspec'd it's rarely used in any C projects. It's shame Dennis's fat pointers / slices proposal was not accepted.

> warrant the additional complexity IMHO

In zig case the comptime reduces complexity, because it is simply zig. It's used to implement generics, you can call zig code compile time, create and return types.

This old talk from andrew really hammers in how zig is evolution of C: https://www.youtube.com/watch?v=Gv2I7qTux7g

1 more reply

quibono11mo ago

Possibly a stupid question... what's a descent span type?

1 more reply

j / k navigate · click thread line to collapse

0 comments

uecker11mo ago

It also works with memcpy from the library: https://godbolt.org/z/Mc6M9dK4M I just didn't feel like burdening godbolt with an inlclude.

CloudefOP11mo ago

> I do not understand your criticism of [N]. This gives compiler more information and catches errors. This is a good thing!

> warrant the additional complexity IMHO

In zig case the comptime reduces complexity, because it is simply zig. It's used to implement generics, you can call zig code compile time, create and return types.

This old talk from andrew really hammers in how zig is evolution of C: https://www.youtube.com/watch?v=Gv2I7qTux7g

1 more reply

quibono11mo ago

Possibly a stupid question... what's a descent span type?

1 more reply

j / k navigate · click thread line to collapse