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
You mean a interpretative language with similar role to Python, but more like Rust/C++ style? I actually want that so that I can ditch Python even if I learned it and use this instead.
Not necessarily interpreted, but possibly. I think a more likely path is something like Go that's compiled but still has a garbage collector.
If you use a garbage collector the whole borrow checker would not make any sense.
Do you want to have error handling and functional paradigms in go? I think you should start there and ask go Devs why their language is lacking such basic stuff.
Not sure if this is what OP is seeking, but I would be fine to have borrow checker removed, replaced with Garbage collector like Go/Python in such a language.
To build prototypes, I don't want to fight with borrow checker and neither I care for efficiency much. But I do want the macro system, traits, lazily asynchronous runtime, cargo like package manager, easy build system, etc.
Rust has so many powerful features, but only because of borrow checker (IMO) we can't use it for rapid prototyping like Python. With that replaced, this subset of Rust would be something which can be a great contender to Python/Go, etc.
The borrow checker handles more than just freeing allocated memory, it will also prevent data races and invalid concurrent access aso. I personally don't have any issues with using garbage collected languages, but the fearless concurrency is nothing I'm willing to give up.
Oh, I agree.
My worst experiences with Python are related to running multiple processes of which share anything. Rust was far easier in that.
Looks like interpreted Rust would be my only demand for Rust to shine in prototyping world.
Honestly, prototyping is exactly the kind of thing where I don't want to think about all the crap that Python doesn't check itself while Rust does. In a long-term project I could begrudgingly learn every data structure and process well enough to do the compiler's job for it but if the code is very new or changes constantly I want as much support from the compiler as possible to avoid having to remember all of that.
Maybe we just need a preprocessor that adds clone, reference counting and RefCell wherever needed.
Then use
.clone()
orArc
everywhere?Why would you want to prototype incorrect code? You don't fight with the borrow checker. The borrow checker prevents stupid mistakes. Anything that is correct that the borrow checker rejects is almost certainly a very bad idea in a prototype
Then Rust is the wrong language for you. Use the right tool for the right job.
Yes, and that's what the post is about.
Saying that Rust is not the right tool for this job, what other tools exist which are similar to Rust but also do the job.
I don't have the answer though. Just came to add my thoughts.