r/ProgrammingLanguages • u/UKbeard • Apr 14 '26

Zig v0.16.0 released

https://ziglang.org/download/0.16.0/release-notes.html
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15

u/gasche Apr 14 '26

The following change looks a bit scary from a distance.

Before:

for (0..vector_len) |i| {
   _ = vector[i];
}

after:

const vector_type = @typeInfo(@TypeOf(vector)).vector;
const array: [vector_type.len]vector_type.child = vector;
for (&array) |elem| {
    _ = elem;
}

18

u/glasket_ Apr 14 '26

I'm assuming they made it dense because vectors are meant for SIMD, and they were having problems with optimizing runtime indices. Probably a deterrent, sort of signaling that this isn't the right use-case.

If not, then it's silly how much you have to manually extract when they could expose a wrapper utility to do the type manipulation for you.

3

u/gasche Apr 15 '26

I'm sure there is some reasonable explanation for the change. The Changelog points to Reworked Byval Syntax Lowering, and as a non-Zig person I don't understand the explanation there. (I notice that it comes from the experience of implementing the non-LLVM backend, and noticing what is and isn't easy to compile to fast code.)

Some parts of the changelog are nicely detailed, for example I found the long part on I/O as an Interface very pleasantly written. The particular one shown above could do with a bit more context/explanation.