hackett VS pie

I am not super knowledgeable about this, but I think you might find Type Systems as Macros interesting. There is also the in-development language Hackett which uses the approach described in the paper to unify Racket style macros with a Haskell style type system.

I agree. I've been searching for solutions for a while. A few choices: - Common Lisp Coalton, very similar to Haskell. - Hackett, a Haskell-like DSL implemented in Racket. Licensing would be an issue, so it would have to be ported to Guile Scheme if you want to build an Emacs out of it. This is not easy since it takes advantage of several Racket-specific language features. - Shen, which can be built on top of Common Lisp, Scheme, Racket, or even Emacs Lisp. The drawback is that it is a fairly cryptic language, and extending foreign language bindings is not well documented. You would basically have to program the entirety of Emacs from scratch - PreScheme is a statically-typed (Hindley-Milner family) subset of Scheme that compiles to C. Originally written to build the Scheme-48 compiler, it is being ported to Guile. Not production read yet. - Zile is an editor engine built on Guile 2.0. But there is no static typing or algebraic data types, it is simply a replacement for Emacs written in Scheme from the ground-up. It needs to be ported to Guile 3.0. Guile 3 has an Emacs Lisp interpreter built-in, but it needs to be developed further before it could run more popular Emacs Lisp applications like Org-Mode or Magit.

Meh. As my final part in this exchange I will leave this here, conclusion are left to the reader: https://lexi-lambda.github.io/hackett/

My dream is something like Hackett, but alas, Alexis didn't have time to continue it. Someday ...

The documentation says it does: https://lexi-lambda.github.io/hackett/

But we can always import Coalton, or Hackett, or miniKanren into our Lisp program if we need it.

This doesn't really answer your question but you may be interested in checking out https://lexi-lambda.github.io/hackett/ by u/lexilambda.

Extremely difficult, but you can do some cool stuff with macros if you do it. Have a look at Alexis King's "Hackett" language for a cool example: https://lexi-lambda.github.io/hackett/

Pie, a dependently typed language for learning dependently typed programming

The computer scientists who are figuring these things out are constructing the tools that software engineers need; just like the mathematicians who developed calculus and the physicists who extended Newtonian mechanics into something engineers can apply. Just as an engineer's tools and materials are calculus and physics (not hammers or concrete and steel), a software engineer's tools and materials are proof-assistants, category theory, linear polarized logic, and dependent type theory (not the Rust programming language or the UNIX platform).

That's basically this[0] book, is it not?

[0] https://thelittletyper.com

I really should read https://thelittletyper.com/

It lets you create languages like Pie which is designed to teach others about dependent types:

https://thelittletyper.com/

Yep, this is one possibility - an example is the language pie from the book The Little Typer. But my claim was not that there are no expressions for types, just that declarations aren't expressions.