pacman.zig VS libcxx

For a somewhat more complete example which runs in browsers, check out my little pacman.zig toy project [0]. This is cheating a bit by using Emscripten toolchain as 'sysroot' (needed for the Emscripten headers), and the Emscripten linker to create the html+js+wasm output file, but the actual code is all compiled with the Zig compiler.

The interesting part is that the platform abstraction is provided by the sokol headers [1], with auto-generated Zig bindings [2]. It's interesting because the C headers use "Emscripten magic" (mainly embedding Javascript snippets in the C sources via the EM_JS() macro), and the Zig compiler is able to compile this (when it has access to the Emscripten headers).

It would be nice if the "Emscripten platform" could get the same type of cross-compilation support as the desktop platforms eventually, but apart from bundling the Emscripten headers, this would also require to implement some of the "Emscripten magic" in the linker step.

Maybe projects like WaJIC can help with this (this basically implements the "Emscripten magic" of embedding Javascript snippets in C/C++ source code, but without Emscripten (only the wasm-opt tool is needed AFAIK).

Anyway... it's a lot of fun to tinker around with this stuff in Zig, and watch how it's all taking shape :)

[0] https://github.com/floooh/pacman.zig

My advice would be: to learn a new language, start writing some non-trivial projects in it (a few thousand lines of code or so). In some languages (like Python), the standard library is the actually important feature, in other languages (like C), it better to mostly ignore the stdlib. Example: I started learning Zig by writing a Pacman clone (https://github.com/floooh/pacman.zig) and a home computer emulator (https://github.com/floooh/kc85.zig), the Pacman clone doesn't use any Zig stdlib features at all, and the emulator only minimally for parsing command line args and loading data from files.

Zig's stdlib is much more useful than C's, but it's still entirely possible to write useful programs without it and instead focus on learning Zig's language features first.

But on the other extreme, the whole point why I learned Python was its "batteries included" standard library.

If you are comparing hoops that library authors need to jump through in both languages, you can easily make the real-world comparison in the other direction, by comparing Rust's Option with C++'s std::optional (an exercise left for the reader): Rust std: https://github.com/rust-lang/rust/blob/master/library/core/src/option.rs libcxx: https://github.com/llvm-mirror/libcxx/blob/master/include/optional

My favorite prime number generator is the undocumented __next_prime():

https://github.com/llvm-mirror/libcxx/blob/78d6a7767ed57b501...

There is no good reason to use this one except in a code golf environment that includes all headers by default, which is where I learned about it.

I once read a Strousroup quote amounting to "If you understand std::vector, then you understand C++". I thought surely he couldn't have meant the interface but the implentation, googled that llvm's implementation is considered nice and clean, had a look, and noped straight out of there.

C++'s STL linked list for comparison (libcxx).

https://github.com/llvm-mirror/libcxx/blob/master/include/li...

> For example, accessing a std::span or a std::vector outside of its bounds would abort the program, and so would accessing an empty std::optional.

I don't really understand the difference with libc++, libstdc++ and msvc stl's respective debug modes, they already do exactly these checks :

- https://github.com/llvm-mirror/libcxx/blob/78d6a7767ed57b501...

- https://github.com/gcc-mirror/gcc/blob/966010b2eb4a4c52f139b...

I mean it's not hard to read the source for your platform. On Linux/x86_64/libc++ it's roughly:

- https://github.com/llvm-mirror/libcxx/blob/master/include/__...

- https://sourceware.org/git/?p=glibc.git;a=blob_plain;f=nptl/...

I don't particularly care to comb through it to see if anything has changed, but historically it was a a little spin-CAS to make the non-contended path fast and then dropping into a https://en.wikipedia.org/wiki/Futex, which is about as good as it gets for staying mostly in userspace but still letting it be scheduler aware so you're not burning up a core busy-polling, which is what often happens when people try to roll their own shit.

Google wants a bit more latitude on the heuristics and degrees of freedom around read/write ownership, so they did it like this: https://github.com/abseil/abseil-cpp/blob/master/absl/synchr... which is quite a bit better commented/legible.

If anyone reading this can do better than the `abseil-cpp` folks, not only would Google take their PR, they'd probably offer them a job.