Deal VS letlang

I started using a design by contract library for a Python project this year and it made my code safer and easier to use.

Have you used Design by Contract in Python projects before? I know that it isn't a first class feature of the language but I see some libraries out there (this one seems potentially promising). Just wondering what the pros and cons are when it comes to gluing DBC onto Python and if anyone can give a yea or nay to it.

deal is a library for Design-by-Contract.

That works for any types (except the functional types), and even the generic ones. During code generation, I create structs that implement the Type trait.

As stated on the website ( https://letlang.dev ), Letlang is a general-purpose language.

Author here, the article is more about how Rust and its ecosystem are nice tools for language designers rather than the beauty of Lisp.

The crates listed in that article are the ones I use for my compiler: https://letlang.dev

Lisp was only chosen as a way to demonstrate the power of those crates and Rust features. A kind of way of justifying my choices for Letlang.

It's not "you should do it like this" but "you can do it like this".

"Faster than C", I saw people write C code slower than a Python equivalent. So I have to admit, I don't know what it means for a language to be fast, because it depends on the algorithm being implemented.

---

"simpler than Python", what does "simple" mean?

Simple design? Python's design is very complex (take a look at "Crimes with Python's pattern matching" < https://www.hillelwayne.com/post/python-abc/ > for example), on the other hand, assembly languages, or Lisp, or Forth, have a very simple design.

Simple as in "easy to use"? Rust is easy, write code, fix what the compiler tells you you did wrong. Joke aside, Go is quite easy to use and while I personally don't like this language, I get why it replaced Python in a lot of use cases.

Also, once you get used to the OTP framework, Erlang/Elixir/Gleam/any beam language are quite easy to use and have less footguns than Python.

---

"safer than Rust" is too vague. Is it memory safety? type safety? thread safety? cosmic ray safety? A mix of all of that?

Let's guess you meant "memory safety". All languages with a Garbage Collector are "memory safe".

---

On a semi-unrelated note, I've been working on https://letlang.dev

It's a language inspired by Erlang/Elixir (same concurrency model) that compiles to Rust code (the runtime use tokio). It is immutable, have no Garbage Collector thanks to Rust semantics, and dynamically typed.

I haven't run any benchmark (it's not even finished, I've been working on the specification before continuing the implementation), but I guess it could be slower than a rock.

---

For some recommendations, have you looked at Zig? Nim? Hare?

  https://ziglang.org/

In my language (Letlang), I use the keyword class with structural pattern matching and optionally a predicate. Types (or rather, classes) can be combined with logical operators &, |, !:

Not sure this is what GP is talking about but to implement the actor model in https://letlang.dev I use tokio.

In the early drafts of Letlang, I had the goal to add an equation solver. I got rid of that because:

I'm working on a programming language inspired by erlang and which compiles to Rust: https://letlang.dev

For a contract based language and a "really dynamically typed language", I'm working on https://letlang.dev

And it's because I haven't thought yet about how to do static type checking with such a feature.

I haven't got any time to work on it in the past few weeks, and I'm the only dev (would really love some help). So, it will be ready when it will be ready :P

I use Rust generators to implement them, a rudimentary example: https://github.com/linkdd/letlang/blob/main/letlang_runtime/src/utils/entrypoint.rs