assemblyscript VS libcxx

Incidentally, it’s also what AssemblyScript uses: https://github.com/AssemblyScript/assemblyscript/blob/main/s...

Use it as a Front-End for other low-level languages.

> MHO typescript could just cut loose from its javascript compatibility. Why not compile it to wasm instead of transpiling it to javascript?

Check out AssemblyScript which is exactly that:

https://www.assemblyscript.org/

If you're curious, check out AssemblyScript, that might describe better what needs to be cut from TypeScript to make it possible to be compiled to WASM.

This is kinda the idea behind AssemblyScript, but IIRC it's more of a low-level typescript-ish syntax for WebAssembly.

https://www.assemblyscript.org/ maybe, but I'm not sure exactly what you need.

Exactly, WASM was designed to be very very lightweight... you can put a lot of logic into a very small amount of WASM, but you need a good compiler to do that, or write WASM by hand to really feel the benefit. If you just compile Go to WASM, with its GC, runtime and stdlib included in the binary, yeah it's going to be pretty heavy... Rust doesn't have a runtime but as you said, for some reason, produces relatively large binaries (not the case only in WASM by the way). Probably, the best ways to create small WASM binaries is to compile from C or from a WASM-native language like AssemblySCript (https://www.assemblyscript.org).

Well we have all the new ECMA standards that will be introduced in 5 years now. It's looking more like Java actually. its accessor and typing patterns match it the most. TypeScript has had quite the profound influence over future ECMA design. There is a not so well known project called AssemblyScript which I think has a promising future. Since future ecma standards closely resembles it and TypeScripts popularity has exploded I have a feeling it may become a real standard as well.

If you can guarantee that Typescript type hints will always be followed, you can turn it into more optimised code. Unfortunately, this means you've got to break Javascript semantics, so this means creating a new language, but people have done it. For example, AssemblyScript is a language that is designed as a strict subset of Typescript that compiles directly down to WebAssembly instead of Javascript, producing much more efficient code (most of the time). The tradeoff is that it has some slightly different semantics to Javascript, which means your existing codebase — and most of the libraries you use — will probably require some adaption before running correctly in AssemblyScript.

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.