TOGVM-Spec VS letlang

Make each AST node an RDF node and then you can cram whatever information into it you want. That's the approach I've been taking with https://github.com/TOGoS/TOGVM-Spec/, anyway.

Of course, for conveniently and safely manipulating in memory in $programming_language, you're probably going to want to define some structs/ADTs/whatever that only contain the data a given compilation stage is actively working with.

I've been thinking that what I need is a system that allows me to quickly define different lower-level datatypes for representing different views of the conceptual types and automate, to some degree, translation between them, so then each part of the system can work with objects designed specifically to be processed by it with minimal fuss.

A technical reason for avoiding those specialized types might be that the computer then has to spend more time transforming from one schema to the next. I would think that in practice this isn't any worse than having to do a lot of null checks.

A more human reason is that it could bean a combinatorical explosion of AST types. I guess this is where my idea about lightweight variations comes in.

In TypeScript this kind of thing might not be so bad, since any object can be downcast with no cost to a type that contains a subset of the information, and variations on types can be easily defined without even necessarily being named, e.g. `ASTNode & HasResultType & HasSourceLocation`.

As far as graph-based languages and languages with arbitrary metadata and relationships between objects are concerned, I've been mulling over a language where expressions are represented as RDF graphs and that has built-in support for manipulating RDF graphs. I've use the concepts as an intermediate representation for functional expressions in a few different systems (including Factorio's map generator), but haven't yet had the motivation to really flesh it out into a full-blown language. https://github.com/TOGoS/TOGVM-Spec

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.

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"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.

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"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".

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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.

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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