rust VS KEEP

For what it's worth, this is the script I'm using to build for our platform: build.ps1 / build.sh

Note that before I got the target triple upstream, I had to provide my own target json file. That's here: https://github.com/betrusted-io/rust/blob/1.53.0-xous/riscv32imac-unknown-xous-elf.json and you can adapt it as necessary. Simply creating the file in the correct path is enough. This is the code that does that: https://github.com/betrusted-io/rust/blob/e39344c5473d49a0cb4d45de119ad23713a00ed4/rebuild.ps1#L65

Everything you need to know to build for our platform is at https://github.com/betrusted-io/rust/ and maybe the scripts or patches there will be interesting to you.

Rust does use a Rust port of dlmalloc on platforms that don't provide malloc() and free(). We did port this to Xous, but ran into a feature bug that caused locking to be disabled. That was the source of weird and subtle bugs, which is how he discovered that fact about allocators.

This is correct.

When you tell someone to install Rust, they go to rustup.rs and install the latest version. Therefore, we need to have a libstd port for the latest version. Which effectively means we need to release libstd as soon as possible after the compiler is released. Our `sys` directory is at https://github.com/betrusted-io/rust/tree/1.61.0-xous/librar... and isn't too complicated. It's about 50 patches that need to be carried forward every six weeks.

Fortunately libstd doesn't change too much, at leaset not the parts we need. And I can usually pre-port the patches by applying them to `beta`, which means the patches against the release version usually apply cleanly.

It's still better than requiring nightly, which has absolutely no stability guarantees. By targeting stable, we don't run into issues of bitrot where we accidentally rely on features that have been removed. Rather than adjusting every service in the operating system, we just need to port one library: libstd

I've considered trying to upstream these, but I'm not sure how the rust team would feel about it.

`Either foo()` and `Foo foo() throws MyError` and are pretty much isomorphic.

https://github.com/Kotlin/KEEP/blob/master/proposals/stdlib/...

Nice. So for example, it looks like Kotlin has a nearly identical feature at the language level which will be optimizable when Valhalla ships: https://github.com/Kotlin/KEEP/blob/master/notes/value-class...

> In the future, in a Valhalla-capable JVM, JVM primitive classes will enable efficient representation of Kotlin value classes with an arbitrary number of underlying fields on JVM.

Most other languages agree that checked exceptions are not good by not having them.

As for alternatives, Try/Result and similar monads have decent adoption even in Java, but personally I quite like the Kotlin philosophy [1] to not have generic error containers and either use runtime exceptions or make failures of the return type.

[1] https://github.com/Kotlin/KEEP/blob/master/proposals/stdlib/...

If you want to read more and don't want to google it: https://github.com/Kotlin/KEEP/blob/data-objects/proposals/data-objects.md

Under the hood: https://github.com/Kotlin/KEEP/blob/master/proposals/coroutines.md .

you can check more here

You can use explicit API mode, then everything needs explicit visibility