tl;dr: I am in wait-and-see mode regarding Rust. The long story:
I have been watching the programming language landscape for some time to see if there is a viable successor to C/C++. C has many advantages: * Standardized (ISO and ANSI standards) since more than 30 years ago, which makes the language very stable. Code that compiles and works today will very likely compile and work tomorrow. * Supported on all hardware. * Supported by numerous compiler toolchains, free and proprietary. * Supported by lots and lots of development tools of all kinds, such as testing and analysis. * Close to the hardware. * Pretty much all operating systems and language interpreters are either implemented in C or implemented in other languages that have a dependency on C. This (in addition to the Lindy Effect [1]) suggests to me that C will be around and well supported for a long, long time to come. C has only one disadvantage that I can think of, which is how easy it is to make dumb mistakes that lead to big problems. This one disadvantage is big enough that many people are searching for a solution in the form of a new, safer programming language. I personally don't think that Rust is necessarily "better" than C (I don't think it's "worse" either). But AFAICT, if there is a language in widespread use that could take over from C, it might be Rust. There is significant interest in Rust and a lot of buzz about Rust around the Internet. There is more than buzz. There is an ongoing effort to use Rust in (isolated parts of) the Linux kernel, as well as the Windows OS. These things are important because when it comes to choosing a language that needs to be supported long term, widespread adoption is arguably the most important factor. The advantages of using Rust in the NuttX OS proper are, we hope, better and safer code. There would be some disadvantages also: Splitting the implementation between C and Rust means: * Needing to know both languages * Dealing with the boundaries between the languages and whatever marshaling needs to be done there * To my knowledge, at this time Rust is *not* standardized by ISO or any other standards organization, and the language is evolving, so we'd need to deal with the incompatibility issues of tracking a specific version of the language and possibly revisiting/rewriting code as new versions of Rust are introduced. This may cause compatibility issues to our users. (Example: What if their application is targeting a different version of Rust than NuttX?) I recently read an article on LWN about Rust in the Linux kernel. I think it was the one at [2]. I highly recommend to read that if we're considering Rust in NuttX to understand what some of the challenges might be, and to learn how the Linux kernel devs are approaching that. Back to my tl;dr about being in wait-and-see mode, I would like to see standardization of the language by a recognized standards body before adopting it for long-term use. That will indicate to me that the language can be expected to stick around for a long time. Also it will allow us to specify to what standard NuttX is written. We'll be able to say NuttX is written to, say, Rust25 (or whatever the number would be), the same way we say NuttX is written to C89. Having said that, if the NuttX community wants to adopt Rust, provided it is well discussed and the issues like evolving language are handled somehow, I wouldn't oppose it. (But at this time, I'm not pushing for it.) Hope this helps, Nathan [1] https://en.m.wikipedia.org/wiki/Lindy_effect [2] https://lwn.net/Articles/952029/ On Wed, Mar 13, 2024 at 2:29 PM Gregory Nutt <spudan...@gmail.com> wrote: > There is some discussion in Issue #11907 proposing to use the Rust > language within the OS (vs Rust applications on a pure C OS). If anyone > has any feelings, Pro or Con, you should participate in this > discussion. This kind of decision impacts the entire community and > should have the input of all of the community that has an opinion. > > >
