In particular, it has two truly remarkable features that no other well-known low-level language -- C, C++, Ada, and Rust -- have or can ever have: lack of macros and lack of generics (and the associated concepts/typeclasses) . These are very important features because they have a big impact on language complexity. Despite these features, Zig can do virtually everything those languages do with macros  and/or generics (including concepts/typeclasses), and with the same level of compile-time type safety and performance: their uses become natural applications of Zig's "superfeature" -- comptime.
Other languages -- like Nim, D, C++ and Rust also have a feature similar to Zig's comptime or are gradually getting there -- but what Zig noticed was that this simple feature makes several other complex and/or potentially harmful features redundant. Antoine de Saint-Exupery said that "perfection is achieved, not when there is nothing more to add, but when there is nothing left to take away." I think that Zig, like Scheme -- and yes, there are others -- is close to that minimalist vision of perfection.
What a truly inspiring language. Rather than asking how we could make C++'s general philosophy work better as another increasingly famous language does, IMO, it asks how we could reshape low-level programming in a way that's a more radical break with the past. I think it's a better question to ask. Now all there's left to hope for is that Zig gets to 1.0 and gains some traction. I, for one, would love to find a suitable alternative to C++, and I believe Zig is the first language that could achieve that in a way that suits my particular taste.
: I guess C has the second feature, but it loses both expressivity and performance because of it.
: Without the less desirable things people can do with macros.
That being said, Zig's comptime is not a proper replacement for typeclasses/traits. Zig can do both comptime duck typing and vtable-based dispatch, but it cannot do proper bounded polymorphism type checking. It always fully evaluates types before type checking them. This might make it difficult (or impossible?) to provide type checking error messages of similar quality to Rust. I'm not sure if there are any other practical consequences for realistic programs, though. I suspect there might be issues around interface stability gaurantees, though I can't quite put my finger on why.
Having said that, I do support a proposal for specifying a type at the parameter declaration with some type -> bool function.
I like this quote by Leslie Lamport about comparing formalisms (he talks about specification languages rather than programming languages, but the sentiment is the same):
> Comparisons between radically different formalisms tend to cause a great deal of confusion. Proponents of formalism A often claim that formalism B is inadequate because concepts that are fundamental to specifications written with A cannot be expressed with B. Such arguments are misleading. The purpose of a formalism is not to express specifications written in another formalism, but to specify some aspects of some class of computer systems. Specifications of the same system written with two different formalisms are likely to be formally incomparable… Arguments that compare formalisms directly, without considering how those formalisms are used to specify actual systems, are useless.
I'm curious where this impression of Zig comes from, as this is precisely what Nim has set out to do: a small core extensible via metaprogramming. Are there features that Nim implements which go against this premise? if so, what are they? :)
Nim has generics (plus concepts), templates, and macros. Zig has just comptime, through which it achieves all those goals (minus some macro capabilities that it deems harmful anyway) with just one, very simple, cohesive construct. You could argue on whether you like this or not, but you can't argue that Zig's approach isn't fundamentally more minimal. Zig is a language you can reasonably fully learn in one day; I don't think you could say the same about Nim.
Also, note another remarkable feature. One could define a language called Zig' with the following properties:
1. Every well-formed Zig program is a well-formed Zig' program (i.e. Zig' accepts all Zig programs, potentially more).
2. Every Zig program has the same semantics as the identical program when interpreted in Zig'.
This means that to analyse the semantics of a Zig program you can pretend it's a Zig' program; in fact, you don't need to create an interpreter for Zig', you can just pretend it exists. Why would you want to do that? Because Zig' is simpler. How? Here's the kicker: Zig' ignores comptime completely. It is a very simple, optionally-typed, dynamic language with reflection.
In other words, to analyse the semantics of a Zig program you can forget about comptime and pretend it can do everything at runtime (and treat comptime as a pure semantics-preserving optimisation).
This is not true for languages with macros, as they are not "erasable".
"some macros" are downplaying Nim macros, it's like saying Lisp has some AST rewrite capabilities.
Nim macros goals are two-folds:
1. adding functionality to the language without baking it in the compiler. A prime example is ``async``, ``async`` including a nice async/await syntax can be completely implemented as a library without reserving keywords to do things like `pub async fn`.
2. Automating away boilerplate.
From what I understood, Zig comptime is only about making compile-time function evaluation first-class.
In other words, there is a capability here that Nim really, really wants, and that Zig really, really doesn't want, so on that front they are not competing in their designs.
I also take issue with your statement that zig is "more minimal" since that only applies to the user's perspective -- from the compiler's perspective, macros make a language far more minimal. But i vaguely recall already discussing this distinction with you so i don't want to rehash it.
At any rate i will definitely be paying attention to andrew's progress, he has a really clear vision.
Macros are controversial. I love them in Scheme and Clojure, but I wouldn't want them in any language aimed at a larger, more mainstream crowd. At the very least, macros introduce another meta-language to know (and if they're in a language with a complex type-level language like Rust or Haskell then they're a third language within the language), but I think it's a matter of personal aesthetic preference.
> But i vaguely recall already discussing this distinction with you so i don't want to rehash it.
Maybe we did. :)
See my comment here about "Zig' ": https://news.ycombinator.com/item?id=24293611
Perhaps now you see what I meant when I said that Zig's simplicity hides its radical design.
You can also do `const a = static(foo(x, y, z))` to force normal function to be evaluated at compile-time and store them in a constants.
Hence you don't need to use macros for compile-time evaluation in Nim just like in Zig. However macros are necessary for AST manipulation.
It's indeed an inspiring language, and rust is taking inspiration from it already: https://github.com/jswrenn/project-safe-transmute/blob/rfc/r...
> lack of generics
I can't wait before Zig2 comes and eventually adds generics…
But C++/Rust can never have Zig's primary feature -- simplicity. Zig's power is not that it has comptime, but that it has little else.
> I can't wait before Zig2 comes and eventually adds generics…
No need. Zig gives you the same capabilities as generics do, only through a separate feature that other languages also have in addition to generics. In other words, it has generics, but without having generics as a special construct. Zig recognises that once you have that other feature (compile-time introspection) you don't need generics as a separate construct, but they can be just an instance of that single construct.
Sounds like a Go pitch, except Zig ain't Go. And while comptime is a cool feature, it's also a really complex one!
> In other words, it has generics, but without having generics as a special construct. Zig recognises that once you have that other feature (compile-time introspection) you don't need generics as a separate construct, but they can be just an instance of that single construct.
This has advantages (only one feature to know), but it also has a big drawback: the lack of orthogonality. C is also simple, for instance it has no concept of errors (only return values) or arrays (only pointers), but most people won't consider this a good idea (and Zig didn't follow C on either of those two design points)
Zig is cool, but I hoped the “generics are too complex of a feature” meme would die now that Go is getting generics, and I'd be really sad to see come back…
No, it's a very simple one, so much so that it's erasable: https://news.ycombinator.com/item?id=24293611 And still it is probably the most complex aspect of Zig.
> Zig is cool, but I hoped the “generics are too complex of a feature” meme would die now that Go is getting generics, and I'd be really sad to see come back…
You've misunderstood me. Generics are a good thing -- if that's all you have. But if you have generics and procedural macros, it turns out that you can do the work of both with a feature that's simpler than either. The capability generics add is a very important one, but given that low-level languages need another one as well, it turns out that generics can be subsumed into that one without being a separate and additional construct. Zig has generic types and concepts/typeclasses; these just aren't atomic language constructs.
Here I think we just have a different subjective perception of what simplicity is. I much prefer have two orthogonal systems which do their own business than having a single more powerful tool than do both (like having slices + references instead of the all powerful pointer)
Anecdotal note: more than 10 years ago, the Go team pitched why they didn't need generics nor macros, because code generation would solve both problems (+ others), and now they're on their way back to add generics to Go (with a lot of hassle).
OK, but that's not quite the situation. Here we're talking about languages that have, or will have, the single "more powerful" construct, and also the more specific, special case one, as two separate constructs, even though one of them would have sufficed.
Again, Zig has parameterized types, and very elegant and powerful ones -- they're functions that take some types as argument and return a type. It just doesn't have generics as a separate construct. Rather, it is a special case of a more general one (that Rust and C++ will also have).
That is a confusing part with C. C do have a concept of arrays, but not as function arguments. You notice it first with multidimensional arrays.
Edit: clearly gp was not mistaken, just imprecise.
I mean, the workarounds are horrible code generation tools and reflection. How were those ever not considered to be more complex than generics?
And if you see the flack that go gets for not including generics then I'm not so sure that that is a great way to get people to adopt your language.