peridot VS schmu

I've mostly finished up a preprint of a research paper on Peridot, my programming language! It still needs some work, but I'm happy enough with it to post it. If you have any questions or suggestions don't hesitate to tell me here. I would love feedback :-)

I'm finishing up with Peridot! The research goals of the project are close to being accomplished, so I'll be wrapping up soon. I'm really satisfied with it as a proof-of-concept for the ideas it implements. The last main bit of the project is a research paper I'm writing which details the language and its applications in detail.

Hey all! I've been working on my programming language Peridot for about six months, and it's finally at the point where I can call it an MVP! Peridot is a language in which the compiler backend is implemented in userspace via metaprogramming.

The Peridot MVP is feature-complete! All that's left to do are bugfixes, after which it will be a real, usable language. Here's the major features, in no particular order:

I'm not aware of any current implementations, but I'll be implementing it in my language, Peridot. Unfortunately that won't be for a few months though.

The second was called Konna. AFAIK it’s Finnish for “frog”, but sources seem to disagree? I don’t speak Finnish, I got the word from a Finnish video game. My third and current language is called Peridot. I’m pretty proud of this name, although it’s less searchable than the previous ones. The origin is pretty simple, I was just looking around at gemstones and thought peridot looked neat.

Hey! I'm Peridot's author. Peridot is a language based on two-level type theory which allows for the compiler backend to be written in userspace. The language is really two languages tied together: a logic language, and a dependently typed functional language. The former is built for metaprogramming - high-level optimizers and compilers can be written that translate the latter language into a target language of choice. An in-depth explanation of the language's rationale can be found here.

Since the last time I posted, I finished implementing pattern matching for schmu. To make matching on multiple columns less confusing I also added a tuple syntax to the language (finally), which are treated as anonymous records in codegen. Since then, I'm trying to overhaul my memory management, as my RAII-like solution only worked for linear code. In my first big departure from OCaml semantics, I decided to implement mutable value semantics. The paper linked in the Val language introduction makes a strong case for value semantics and after watching a couple of talks by Dave Abrahams, I wanted to try see how it feels. By making mutability be transitive and explicit, it also fixes one of the (few) gripes I have with OCaml that an array can never be really const as it is a reference type (it's possible to enforce constness with modules, but that's not exactly lightweight, syntax wise). Implementing mutable value semantics was pretty straight forward on the typing side, but I'm still not completely done with the codegen. This is due to 1. Assumptions about immutability I made in a lot of places are now wrong, and I had to completely change the way I pass values to functions. 2. I had to implement reference counted arrays, which was more work than I thought it would be. There are still edge-cases coming up in testing from time to time. Yesterday I finally managed it work for tail recursion, yay! I'm looking forward to getting rid of unneeded reference count updates in the future, by moving them to compile time, at least for linear code, lobster style. That's also an excuse to read that Perceus paper again. For the rest of November, I want to enhance my module system a bit. In particular, I want to add signatures and allow locally abstract types. I hope to have this in place before December to do the Advent of Code in my language.

I'm still working on my toy language schmu, an ML-inspired language which uses LLVM as backend.

I spent the time off over the Easter break to write the first program in my language which is not an explicit test and ended up implementing Ray Tracing In One Weekend. It was very rewarding to see how usable the language is already.