Re:A technical vision for the Haskell ecosystem
by calebkaiser on Friday November 13, 2026 @05:34PM
(#50491028)
Yeah, I think this is roughly where things are headed. And I think this is actually in the design of many languages already. This is made especially powerful by languages like Lean, as you can prove that the presentable API is correct.
Here's one rough example that is related to this direction:
A common convention in Lean is to write essentially two versions of a function, with a theorem proving their equality or correspondence.
So you can write a more demonstrative version that is more easily understood, which you can treat sort of as a spec that all other implementations must satisfy. And then you can set the agent loose to do whatever nastiness it wants to do to improve performance.
Here's a fun write up from someone doing just this with zip file compression: https://kim-em.github.io/blog/2026-7-24-why-lean-is-faster-t...
So, I could write what I want in haskell, and it's faster for me than to have an LLM do it. The haskell would be high-level enough and precise enough to describe what I want the program to do with less iterations than I'd have with an LLM writing code, finding its own bugs, fixing them, then having me ask it what it did, tell it what to do differently, etc.
Direct control is very powerful. LLMs take that away from us, in exchange for a great speedup. But perhaps we can use LLMs to give it back to us by making our actual programming languages more powerful.