[zellyn]

One notable thing about Zig (and Andrew) is their willingness to rethink everything, and a lack of fear of digging all the way down and building their own versions of underpinning things. They believe incremental compilation should be an option, so they have to write their own compiler, linker, etc. They're already pushing the boundaries of what new languages can do, and—eventually—will be expected to do.

[Edit: expanding]

For instance, completely platform-independent cross compilation is something Go popularized, but Zig really nailed. (In fact, if you use cgo, the generally accepted method for Go cross-compilation is to use Zig as the C compiler!)

Another interesting thing about Zig is that it happily compiles C code, but brings more modern package management. Loris Cro has described how it would be quite reasonable (and pleasant) to maintain C code using Zig: https://kristoff.it/blog/maintain-it-with-zig/

[ksec]

>They believe incremental compilation should be an option

May be more accurate should be they believe compiling should be insanely fast. And incremental compilation is part of the tools to achieve that.

[jvillasante]

What does incremental compilation have to do with writing your own compiler from scratch? Isn't Rust supports incremental compilation as does every language out there?

[pbaam]

I guess he means that in order to achieve incremental compilation they need to write their own code generation and linker for every architecture and format. This is needed because incremental compilation here doesn't just mean storing object files in a cache directory (which has always worked that way). They also want to cache every analyzed function and declaration. So they have to serialize compiler state to a file. But after analysis is done, LLVM will start code generation from the beginning (which is the time expensive thing, even in debug builds)

[jvillasante]

Yes, but isn't that an implementation detail? Shouldn't they prioritize getting to 1.0 (the language itself) and then work in implementation details like that? I mean, It's a monumental task to write compiler and linker from scratch!

[pbaam]

Well, if your compilations turn to be submilisecond it's not an implementation detail :) *. As of now it is only supported for x86_64 Linux (only ELF format) and it has some bugs; incremental compilation is in its very early stages. Andrew talked about it in the 2024 roadmap video[1] why they are digging so low on the multiplatform toolchain (for besides incremental compilation):

- Fast build times (closely related to IC, but LLVM gives very slow development iterations, even for the compiler development)

- Language innovations: besides IC, async/await is a feature Andrew determined to not be feasable to implement with LLVM's coroutines. Async will likely not make it into 1.0, as noted in the 0.13 release notes. It is not discarted yet but neither is it the priority.

- There are architectures that don't work very well on LLVM: SPARC and RISC-V are the ones I remember

My personal point is that a language that is meant to compete with C cannot have a hard dependency on a C++ project. That, and that it's appealing to have an alternative to LLVM whenever you want to do some JIT but don't want to bring a heavy dependency

[1] https://www.youtube.com/watch?v=5eL_LcxwwHg

* There is also the `--watch` flag for `zig build` which re-runs every step (IC helps) everytime a file is saved.

[edit: formatting]*

[pjmlp]

Ironically all major production C compilers evolved to be written in C++.

Also if they value compilation speed that much, maybe they shouldn't be that pushy into compiling always from source, without any support for Zig binary libraries.

[geodel]

> Shouldn't they prioritize getting to 1.0 (the language itself)

Nope. Different languages have different priorities and different USPs. For Zig sub-second compilation / incremental compilation, cross compiling toolchain are flagship features. Without those there is no point in releasing 1.0.

[zellyn]

They want incremental compilation at the function level. So if you change a function, you recompile just that function. This necessitates a custom linker (indeed a custom linking strategy), and (I think?) a custom compiler.