frontpage.
newsnewestaskshowjobs

Open Source @Github

fp.

Open in hackernews

The Lisp in the Cellar: Dependent types that live upstairs [pdf]

https://zenodo.org/records/15424968
88•todsacerdoti•1y ago
Downloadable: https://zenodo.org/records/15424968/files/deputy-els.pdf

Comments

droideqa•1y ago
Sadly "deputy clojure" on Google brings no results...

The only hint is this repo[0] referenced in the paper.

[0]: https://gitlab.com/fredokun/deputy

agumonkey•1y ago
Pretty readable code
reuben364•1y ago
Thinking out aloud here.

One pattern that I have frequently used in EMACS elisp is that redefining a top-level value overwrites that value rather than shadowing it. Basically hot reloading. This doesn't work in a dependently typed context as the type of subsequent definitions can depend on values of earlier definitions.

    def t := string
    def x: t := "asdf"
    redef t := int
redefining t here would cause x to fail to type check. So the only options are to either shadow the variable t, or have redefinitions type-check all terms whose types depend on the value being redefined.

Excluding the type-level debugging they mention, I think a lean style language-server is a better approach. Otherwise you are basically using an append-only ed to edit your environment rather than a vi.

extrabajs•1y ago
I don’t see the connection to dependent types. But anyway, is ‘redef’ part of your language? What type would you give it?
reuben364•1y ago
I just wrote redef to emphasize that I'm not shadowing the original definition.

    def a := 1
    def f x := a * x
    -- at this point f 1 evaluates to 1
    redef a := 2
    -- at this point f 1 evaluates to 2
But with dependent types, types can depend on prior values (in the previous example the type of x depends on the value t in the most direct way possible, as the type of x is t). If you redefine values, the subsequent definitions may not type-check anymore.
extrabajs•1y ago
I see what you mean. But would you not experience the same sort of issue simply from redefining types in the same way? It seems this kind of destructive operation (whether on types or terms) is the issue. As someone who's used to ML, it seems strange to allow this kind of thing (instead of simply shadowing), but maybe it's a Lisp thing?
resize2996•1y ago
> EMACS elisp

I used this to write the front end for an ATM machine.

wk_end•1y ago
I've fantasized about some kind of a dependently-typed Smalltalk-like thing before, and in those fantasies the solution would be that changes would be submitted in the form of transactions - they wouldn't be live until you bundled them all together into one big change that would be fully type-checked, as you describe.
dang•1y ago
Any URL for this that we can open in a browser (as opposed to the dreaded "Content-Disposition: attachment")?
Jtsummers•1y ago
https://zenodo.org/records/15424968 - This at least takes you to a webpage where you can view the paper. If you select to download it, it still downloads of course instead of just opening in the browser.
dang•1y ago
Thanks! I've switched to that above, and put the downloadable link in the top text.
reikonomusha•1y ago
Related context: The 2025 European Lisp Symposium [1] was just wrapped a few hours ago in Zurich. There was content on:

- Static typing a la Haskell with Coalton in Common Lisp

- Dependent typing with Deputy in Clojure (this post)

- The Common Lisp compiler SBCL ported to the Nintendo Switch

- Common Lisp and AI/deep learning

- A special retrospective on Modula and Oberon

- Many lightning talks.

[1] https://european-lisp-symposium.org/2025/index.html

no_wizard•1y ago
I feel like Lisp would be an ideal language for AI development. Its exceedingly good for DSL development and pattern matching. Its already structurally like math notation as well, which I would think would lend itself to thinking how models would consume information and learn
rscho•1y ago
Well... believe it or not, some have thought of using lisp for AI for quite some time. ;-)
froh•1y ago
indeed.

Peter Norvig, 1992

Paradigms of AI Programming: Case Studies in Common Lisp

https://g.co/kgs/hck8wsE

https://en.m.wikipedia.org/wiki/Peter_Norvig

it's no coincidence Google is actively maintaining sbcl, either.

Zambyte
fithisux•1y ago
Impressive.
kscarlet•1y ago
The only option that you described is called "hyperstatic global environment".

And it is called that for a reason, it is not very dynamic :) and probably too static to the taste of many Lisp and all Smalltalk fans.

•
1y ago
Why not go all the way to the source? John McCarthy coined the term "artificial intelligence", and then invented / discovered LISP in pursuit of it in the 1950s :D
ayrtondesozzla•1y ago
https://quantumzeitgeist.com/lisp-and-the-dawn-of-artificial...

Lisp was the de facto language of artificial intelligence in the U.S. for many years. Apparently Prolog was popular in Europe (according to Norvig's PAIP)

Residential proxies detected on White House network

https://layer3intel.com/blog/residential-proxies-white-house-network
842•Rasbora•8h ago•268 comments

Images 2.6

https://openai.com/index/introducing-images-2-6/
191•davidbarker•5h ago•131 comments

A thousand fewer paths to root

https://openai.com/index/a-thousand-fewer-paths-to-root/
231•dangelosaurus•5h ago•129 comments

Starfall – Affordable, routine access to microgravity

https://www.spacex.com/starfall
168•gmays•5h ago•104 comments

Ripple-65B Preview: U.S. Open-Weight SOTA on Agentic Coding

https://www.ricursive.com/ripple
264•Philpax•10h ago•94 comments

Kimi K3.1 Pro model weights are out

https://huggingface.co/moonshotai/Kimi-K3.1-Pro
436•abrarthought•13h ago•130 comments

Insects don't swarm at LED lights

https://www.birdsoutsidemywindow.org/2026/11/03/insects-dont-swarm-at-led-lights/
210•speckx•9h ago•113 comments

A new Go API for JSON

https://go.dev/blog/jsonv2
262•olexsmir•11h ago•119 comments

Spreading Liquid with Three.js

https://mofu-dev.com/en/blog/fluid-foundation/
17•mooreds•2d ago•3 comments

Hacking the Xbox 360 Hypervisor Part 3: Bad Update Improvements

https://icode4.coffee/?p=1746
86•muricula•7h ago•5 comments

Conductor is joining Meta

https://www.conductor.build/announcement
148•kenrose•11h ago•168 comments

Show HN: After a decade of reversing, I got co-op working in DOS Wing Commander

https://fireflyk64.github.io/wcmulti/
143•daniel_rh•10h ago•16 comments

Qualcomm Cloud AI 100 Ultra – 150W AI Accelerator Card with 128GB at 548GB/s

https://www.qualcomm.com/data-center/products/cloud-ai-100-ultra
125•peter_d_sherman•9h ago•53 comments

Progress on provable inference for large language models

https://www.anthropic.com/research/provable-inference
198•ltononro•12h ago•87 comments

Launch HN: Kino AI (YC S23) – AI media manager and video editor

80•lukeigel•11h ago•31 comments

AI is forcing us to pay off 40 years of technical debt

https://spectrum.ieee.org/ai-in-cybersecurity-php2shell-vulnerability
1131•pseudolus•17h ago•658 comments

Ask HN: What's your current AI agentic setup?

216•eggbrain•14h ago•218 comments

Guerrilla bike lanes: San Francisco makes illicit infrastructure permanent (2016)

https://99percentinvisible.org/article/guerrilla-bike-lanes-san-francisco-makes-illicit-infrastru...
281•zenincognito•14h ago•203 comments

OpenAI to acquire Pierre Computer Company

https://openai.com/index/openai-to-acquire-pierre/
215•itunpredictable•14h ago•66 comments

Basically no one is using AI agents for their DoorDash orders

https://arstechnica.com/ai/2026/10/doordash-says-outside-ai-agents-have-only-led-to-hundreds-of-o...
102•PaulHoule•2d ago•194 comments

Tencent Hy4

https://hy.tencent.ai/research/hy4
213•Philpax•15h ago•70 comments

A wave of plastic-free coffee pods and machines

https://www.cnn.com/2026/11/02/food/coffee-machine-plastic-free
65•thunderbong•14h ago•82 comments

Show HN: The DNA of DOOM – How code structure survives across 44 ports

https://squid-protocol.github.io/gitgalaxy/museum-of-code/doom-dna/
39•joe-esquibel•2d ago•19 comments

11 Nanoseconds per Word: Over-Optimizing Anagrams

https://wiredream.com/anagram-fun/
12•ColinWright•19h ago•0 comments

Is Curiosity Good for Us?

https://www.lrb.co.uk/the-paper/v48/n20/adam-phillips/is-curiosity-good-for-us
34•NaOH•1d ago•17 comments

'It's just vape, nail, charity shops': Can anything save UK high street?

https://www.theguardian.com/business/2026/nov/04/what-can-save-the-british-high-street-rotherham
95•theanonymousone•13h ago•202 comments

AMD expects to outsell Intel in Q4 for the first time in history

https://www.tomshardware.com/pc-components/cpus/amd-expects-to-outsell-intel-in-q4-for-the-first-...
514•rbanffy•13h ago•189 comments

PageScribe: Handwriting and offline dictionary audio for KOReader

https://aspireai.kiranadimatyam.com/builds/pagescribe/
18•seshakiran•2d ago•1 comments

Ask HN: What cryptography book do you recommend for reading with 10 year olds?

65•mike_richards•2d ago•63 comments

Tell HN: Gemini trains on chat history, even for subscribers (personal accounts)

643•jameslk•19h ago•168 comments