Almost five years ago, Saoirse “boats” wrote “Notes on a smaller Rust”, and a year after that, revisited the idea.
The basic idea is a language that is highly inspired by Rust but doesn’t have the strict constraint of being a “systems” language in the vein of C and C++; in particular, it can have a nontrivial (or “thick”) runtime and doesn’t need to limit itself to “zero-cost” abstractions.
What languages are being designed that fit this description? I’ve seen a few scripting languages written in Rust on GitHub, but none of them have been very active. I also recently learned about Hylo, which does have some ideas that I think are promising, but it seems too syntactically alien to really be a “smaller Rust.”
Edit to add: I think Graydon Hoare’s post about language design choices he would have preferred for Rust also sheds some light on the kind of things a hypothetical “Rust-like but not Rust” language could do differently: https://graydon2.dreamwidth.org/307291.html
The designers of Go actually discussed civilised error handling (like Rust and others), but in order to make it useful they’d have to include other features like ADTs and something like an
Eithermonad (Result type), which they felt would make Go too difficult to learn for the developers they envisioned Go to be used by.One of the most important reasons for the popularity of Go is exactly that it is extremely limited, and can be picked up by any developer in a few hours. It takes no time to learn because there is nothing there that would need to be learned. This isn’t a limitation, it’s a feature (opinion of Go designers, not mine).