Comment by yellowapple
5 years ago
> What do you find radical about Zig?
Personally, I find the "bring your own allocator" philosophy to be pretty radical. Yeah, other systems programming languages can facilitate additional allocators beyond "the" allocator for the language's runtime, but Zig seems to optimize for that case, which makes it a lot more intuitive from a learning perspective (no more guessing about where the memory lives). Even Rust (last I checked) defaults to assuming some global one-size-fits-all allocator.
There's also Zig's flavor of compile-time code / metaprogramming. It's probably less powerful than Rust's macros, but I feel like it's a lot cleaner and intuitive, and I'd argue that being able to run ordinary Zig code at compile time is powerful enough of a feature for Zig's use cases. Ultimately, it's a nice happy medium between full-blown metaprogramming (like in Lisp and - from what I understand - Rust) v. preprocessing (like in C/C++).
And yeah, I'm sure there's plenty of prior art for everything that Zig does, but I don't know of any other languages that combine these things in such a simple and intuitive and principle-of-least-astonishment-friendly way Zig does.
> Even Rust (last I checked) defaults to assuming some global one-size-fits-all allocator.
You can substitute whatever allocator you want: https://doc.rust-lang.org/std/alloc/trait.GlobalAlloc.html
Unless you're talking about some other restriction I'm not aware of.
In Zig, you can provide a different allocator for a single data structure (or even distinct instances of the same data structure). There is no "global" allocator (what Rust lets you swap out.)
This is vastly more powerful, I have used this to tailor an allocator to specific data structures for better performance.
That is what they're referring to, it is a single global allocator, rather than a per-data structure or per-instance one. You can do this in Rust, there's just no abstraction for it. One is coming.
I don't know Zig, but it sounds like Zig allows to use arbitrary allocators for anything. The abstraction Rust is getting will only work for things that do account for using arbitrary allocators. Anything that doesn't will end up using the global allocator. That's a significant difference.
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What's the use case? I'm trying to think of a situation where you'd want to do that were you might not just make a separate binary that uses the other allocator
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