I've had a discussion with several people recently about future possibilities of Rust in GNU Emacs core. I could not find an answer to this on the archives, so if it has been resolved previously please point me to that thread.
Let assume for the sake of this discussion that there was a some Rust code that someone wanted to contribute and the maintainers wanted the functionality it provided. What would be the consideration/objections? Here are few that we came up with:
- The Rust tool-chain is Apache licensed and so is LLVM. There is work on a GCC backend, but it is not production ready yet. Would Emacs allow the current Rust tool-chain?
- LLVM (and hence Rust) support fewer targets than GCC. Are there certain target that LLVM doesn’t support that are important to Emacs?
- Many Rust libraries (crates) are MIT and/or Apache licensed. Do all Libraries used by GNU Emacs need to be GPL or is it sufficient to have a GPL compatible license?
- How sizable of a contribution would be needed for the maintainers to accept Rust in Emacs core? Would auxiliary functionality be considered (such as Rust in the Linux Kernel) or would it need to have major impact.
- Concerns over having more than one core language in GNU Emacs.
- Concerns over using such a new language. Rust still changes at a fast pace relative to C and it’s future is less certain then a more established language.
- Concerns over support for Rust being a distraction from other development work.
- I assume that FSF copyright would still be a requirement. I just bring it up so no one else has to.