Liskell – Haskell Semantics with Lisp Syntax [pdf]

Posted by todsacerdoti 1 day ago

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Comment by vindarel 17 hours ago

The other way round, a Haskell on top of a Lisp, in production today: https://github.com/coalton-lang/coalton/

> Coalton is an efficient, statically typed functional programming language that supercharges Common Lisp.

Presentation this year on the ELS: https://www.youtube.com/watch?v=of92m4XNgrM

Comment by dieggsy 16 hours ago

I'm not sure I'd say this is "the other way around"; Coalton strives to implement Haskell or ML-adjacent semantics (in the type system, for example) with Lisp syntax. "With" here meaning that it is both implemented in and written with Lisp syntax.

Edit: I think I see what you mean now. Lisp backend vs Haskell backend.

Anyway, Coalton is a joy to use and IMO a breath of fresh air in CL. It's quite easy start using as a library; go all-in or only use it in specific parts of the code. It's great to be able to choose between (or intermix)the flexibility of CL and the guarantees of a statically typed language (as well as some nice performance boosts with arguably less work). Some aspects are still young (some of the standard library, ecosystem, editor support), but it's quite thoughtfully crafted and I'm excited to see where it goes.

Comment by flavio81 14 hours ago

>Coalton strives to implement Haskell or ML-adjacent semantics (in the type system, for example) with Lisp syntax. "With" here meaning that it is both implemented in and written with Lisp syntax.

Not exactly. Coalton brings ML-style strong typing to Common Lisp. But Coalton code is also Lisp code.

The backend, thus, is Common Lisp, and it is available at all times, thus leveraging all its power.

Comment by bjoli 18 hours ago

I will prempt the comment that always shows up in discussions of this kind:

No. Typeclasses do not replace proper macros. Go home, you are drunk.

Comment by BalinKing 17 hours ago

Another argument I've often heard is that laziness largely obviates macros. Personally, I agree that this is often true—but not always, and that last bit is where Lisp-style macros would be really nice.

(^^ edited based on one of the responses below.)

Comment by Symmetry 16 hours ago

The venerable master Qc Na was walking with his student, Anton. Hoping to prompt the master into a discussion, Anton said "Master, I have heard that objects are a very good thing - is this true?" Qc Na looked pityingly at his student and replied, "Foolish pupil - objects are merely a poor man's closures."

Chastised, Anton took his leave from his master and returned to his cell, intent on studying closures. He carefully read the entire "Lambda: The Ultimate..." series of papers and its cousins, and implemented a small Scheme interpreter with a closure-based object system. He learned much, and looked forward to informing his master of his progress.

On his next walk with Qc Na, Anton attempted to impress his master by saying Master, I have diligently studied the matter, and now understand that objects are truly a poor man's closures." Qc Na responded by hitting Anton with his stick, saying "When will you learn? Closures are a poor man's object."

At that moment, Anton became enlightened.

Comment by merelysounds 16 hours ago

Some fun code examples in Ruby: https://medium.com/@citizen428/of-closures-and-objects-e9507...

Comment by jasbrg 17 hours ago

do you know of a post or something you could point to that elaborates that argument? interested because I'm having trouble coming up with the line of reasoning on my own

Comment by BalinKing 16 hours ago

I'm having trouble finding anything concrete online (other than people simply repeating the folk wisdom) other than control flow operators, which are implemented as normal functions in Haskell (i.e. including custom control flow operators).[0] Although, one Reddit comment[1] did also mention typeclasses as obviating other types of macros, so I've edited my earlier comment accordingly.

[0] https://www.reddit.com/r/haskell/comments/5xge0v/comment/deh...

[1] https://www.reddit.com/r/haskell/comments/1929xn/comment/c8k...

Comment by ddellacosta 16 hours ago

This is not a direct response to the question of how laziness obviates the need for macros, but it mentions some specific relevant cases:

https://augustss.blogspot.com/2011/05/more-points-for-lazy-e...

Comment by Y_Y 16 hours ago

I'll get in trouble if I show up this drunk at this hour, can't I just bolt on a templating system?

Comment by EricRiese 18 hours ago

There's also Hackett: Haskell with Racket's syntax and macro system, by Alexis King

Comment by privong 16 hours ago

To save folks a search:

github repo: https://github.com/lexi-lambda/hackett

Documentation: https://lexi-lambda.github.io/hackett/

Comment by srott 17 hours ago

How does it compare to Shen?

https://shenlanguage.org

Comment by adastra22 17 hours ago

Kinda hard to tell when I can’t find a single example of the language on its website.

Comment by srott 6 hours ago

really, I did't realize there was no link

https://shen-language.github.io

Comment by adastra22 5 hours ago

Ok well that at least has examples of the syntax. But not a single example of actually using the language to do anything. That is, no examples of actual code.

It took a while to click through a link to an actual implementation on github, which had some test examples. None of which were documented.

So idk? I'm not going to buy the ebook for $41 to find out.

So to answer your original question: Liskell, despite being 13 years old and unmaintained, does actually have an accessible document that _explains what it is_.

Comment by swatson741 17 hours ago

Date of publication is from 2007.

Comment by fithisux 17 hours ago

It is time for Rusted !!!

Rust semantics with D syntax (garbage collector is a bonus).

Comment by Xophmeister 17 hours ago

Didn’t D get an ownership model, a la Rust’s affine types, relatively recently?

Comment by fithisux 9 hours ago

I don't think so, but they are working towards it.

The big news is that this will cover the GC cases too, not only the manual memory management.

Comment by felipelalli 16 hours ago

Savior of the universe.

Comment by skywhopper 16 hours ago

I was told Lisp didn’t have syntax.

Comment by zephen 12 hours ago

It has minimal, very regular, syntax.

Which is a strength in some aspects, and, although many lispers will never admit it, a weakness in others.

Comment by tug2024 15 hours ago

[dead]