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After 7 years in production, Scarf has reluctantly moved away from Haskell

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Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#11

Post by jasim »

I'm curious about the choice of Python, rather than TypeScript.

I find Ruby a very beautiful language, and Rails is an excellent web framework, but I need typed functions, record types and sum types.

They help not just with correctness, but also as living documentation that lets me understand AI generated code. TypeScript provides discriminated union, but not exhaustive pattern-matching, and its syntax is a bit verbose, but since I'm no longer writing most of the code myself, I can live with it.

However I can't imagine using Python or any other dynamic language going forward. There is likely good reason for you to choose it, and I'm curious to know what that is.

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#12

Post by rowanG077 »

This is quite insane to me. If I compare the output of LLMs for python vs statically typed languages it's really not a good choice to go the python route. It consistently produce relatively garbage code along actually good code. My experience has that the better static typing you have the better the code becomes.

LLMs have made me move away more from python rather than into it. I'm very surprised by this experiences of the author. The article is all over the place as well. Going basically all in on Python because it is apparently better than Haskell for LLM use and than agreeing with someone that says Rust is the best.

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#14

Post by zitterbewegung »

matt2000 wrote: post #5

I am increasingly wondering if we are in a post-language world in terms of development. Why would I ask an agent to write a server in anything other than the most efficient language, although efficiency can take several forms: runtime, token usage during development, and wall clock dev time (affected by slow compile times for example). My intuition is that type-safe languages with fast compilers are the best option.…

There is one simple thing you have to realize why Python is the optimal choice. You have so much training data. Python is the second most popular language on GitHub and is easy to read.

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#15

Post by calebkaiser »

I've been a power user of LLMs for software development for a while now, and I've found two things to be true:

- The benefits of more "extreme" type systems are more accessible and valuable than ever. I have a fairly involved project built on Lean that I hope to open source this month, and it's been a joy to work in even for uses outside of mathematics.

- Readability, build time, infra complexity, and everything that affects your speed after finishing your implementation--these things now matter more than ever.

It's sort of a dual ergonomics problem, in some sense. And given that, the author's lament makes complete sense to me, especially:

"An AI-enabled Haskell ecosystem would ask different questions. How do we make Haskell easier for agents to use well? How do we get more high-quality Haskell examples into model training data? How can we scale reviews? How do we make library docs full of copy-pastable, realistic examples, not just beautiful types? How do we make project bootstrap fast? How do we make error messages more agent-friendly? How do we reduce cold build times? How do we make common industrial patterns obvious to a model that is trying to help?"

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#16

Post by lp4v4n »

I'm not a Haskell developer and I hadn't heard of this company "Scarf" before.

As much as I respect this guy who tried to work and push an alternative ecosystem, it's hard for me to shake off the impression that, rather than due to Haskell compile time, he moved to python because it's easier to find developers for it and it's the de facto scripting language for LLMs.

No problem about that, of course. Running a company is hard enough, I think that passion and idealism for a language/platform/technology out of aesthetic appreciation can only go so far and after a certain age just making money and reaching your professional objectives count more.

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#17

Post by koito17 »

noelwelsh wrote: post #2

Wow. Not a Haskell user, but a big user of other languages with expressive type systems (mostly Scala; some Rust). My experience is the complete opposite. I can't imagine using a language without a good type system to catch all the junk the LLM produces. In fact I thought people would move away from languages from poor type systems, like Python, given the cost of using languages with expressive type systems has decre…

Recently had to touch a Python project at work. Just setting up the editor needed me to use 2-3 tools out of: pyright, basedpyright, ruff, ty, mypy, and possibly other tools I'm forgetting that kind of do the same thing but throw errors in different parts of the codebase.

Also, for some reason Optional[T] became deprecated, just as the ecosystem finally embraced types ~3 years ago.

In fact, one my company's greenfield projects decided to use TypeScript instead of Python for the [surprisingly] more consistent tooling, and the fact that the big LLM providers all have official TypeScript SDKs anyway. Also, for agentic coding, LLMs don't seem noticeably worse at TypeScript than Python.

My experience can be summarized as:

- for some reason we need 2-3 static analysis tools just for typechecking

- no tool understands each other's comment directives

- each tool reports a different error in your codebase

- even big libraries (e.g. matplotlib) make half their functions return Any

- you'll be tempted to silence the "partially unknown type" warnings, and you'll have to do it for each tool that's running.

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#18

Post by calebkaiser »

noelwelsh wrote: post #2

Wow. Not a Haskell user, but a big user of other languages with expressive type systems (mostly Scala; some Rust). My experience is the complete opposite. I can't imagine using a language without a good type system to catch all the junk the LLM produces. In fact I thought people would move away from languages from poor type systems, like Python, given the cost of using languages with expressive type systems has decre…

I think the author largely agrees with you re: type systems and LLMs. He's pretty explicit that Haskell should be very well positioned to be a power language for LLM-assisted programming, but that the Haskell ecosystem presents the bottlenecks that make it harder.

I don't personally use Haskell for anything, but I use Lean and occasionally some other languages with expressive type systems, and like you I've found it to be a pretty great experience for working with LLMs. But I've also experienced what the author is talking about, with languages that sit at different points on the type system spectrum, regarding a languages ecosystem/infra layer becoming a bottleneck. I don't think it's ultimately about the type system but the broader ergonomics of the language/ecosystem.

So I think his criticism is less than expressive type systems are a pre-LLM concept, and more that Haskell has an individually bad "agentic coding story".

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#19

Post by em-bee »

jasim wrote: post #11

I'm curious about the choice of Python, rather than TypeScript. I find Ruby a very beautiful language, and Rails is an excellent web framework, but I need typed functions, record types and sum types. They help not just with correctness, but also as living documentation that lets me understand AI generated code. TypeScript provides discriminated union, but not exhaustive pattern-matching, and its syntax is a bit verbo…

python has optional types too now. if you could get the LLM to produce typed python would it be any worse than typescript?

Re: After 7 years in production, Scarf has reluctantly moved away from Haskell

#20

Post by domenkozar »

We at Cachix have also moved on from Haskell about two years ago and I'm sure someone is going to make a comeback with a language that takes the lessons from it but starts from skratch.

We need more general purpose Elm languages in the space.

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