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)

Retrospectively Reverse-Engineering Apple's Neural Engine

https://eiln.github.io/posts/ane.html
62•zdw•1h ago•9 comments

IKEA made a mod for Skyrim [video]

https://www.youtube.com/watch?v=iZODN0QUgjI
69•kegenaar•2d ago•11 comments

A misalignment of AI in mathematics

https://mathandai.org/
915•meredydd•15h ago•879 comments

I spent $220 on Google app ads and 60% of the installs were robots

https://dayzlegame.com/blog/google-ads-bot-farm/
522•nickabe•15h ago•273 comments

Navier-Stokes Announcement

https://www.claymath.org/news/navier-stokes-announcement/
155•rvz•5h ago•102 comments

Usenet rewind archive search engine

https://www.usenet-rewind.com/
59•cstadler1869•5h ago•12 comments

google.com/goto: Google's anti-scraping update

https://www.autom.dev/blog/google-search-goto-links
418•1e1a•6h ago•320 comments

A Design Space Exploration of Async/Await

https://cel.cs.brown.edu/blog/design-space-async-await/
280•wcrichton•2d ago•71 comments

Great Lakes sturgeon may be 400 years old:Scientists rethinking how to save them

https://www.cbc.ca/news/canada/ontario-great-lakes-sturgeon-lifespan-study-9.7329250
67•bookofjoe•2d ago•3 comments

Inverse Kinematics and Foot Locking

https://theorangeduck.com/page/inverse-kinematics-foot-locking
34•airhangerf15•5d ago•1 comments

Show HN: Bodily Oddities

https://vester.si/bodily-oddities/
245•vesterde•1d ago•167 comments

Designing for Dual Screen and Foldable Devices with CSS (2023)

https://blog.stephaniestimac.com/posts/2023/05/design-foldable-devices/
33•mooreds•1d ago•6 comments

Logo Programming

https://el.media.mit.edu/logo-foundation/what_is_logo/logo_programming.html
280•azhenley•3d ago•113 comments

OpenAI agents carried out an undisclosed attack on RubyGems

https://www.rubyhack.ai/
699•chao-•10h ago•394 comments

Project Blinkenlights

https://blinkenlights.de/en/
90•doener•11h ago•30 comments

Mind-altering drugs played key role in rise of Andean civilization

https://www.science.org/content/article/mind-altering-drugs-played-key-role-rise-andean-civilization
161•geneticdrifts•16h ago•104 comments

Litelm: LiteLLM Without the Bloat

https://github.com/kennethwolters/litelm
136•kennethwolters•15h ago•46 comments

I've operated petabyte-scale ClickHouse clusters for 5 years

https://www.tinybird.co/blog/what-i-learned-operating-clickhouse
214•adastral•4d ago•78 comments

Detailed report on the use of solar geoengineering

https://www.technologyreview.com/2026/09/10/1143804/this-road-map-could-help-us-decide-whether-to...
7•coloneltcb•1d ago•0 comments

GrapheneOS' rewritten Messages app is released

https://github.com/GrapheneOS/Messaging/releases/tag/13
277•microtonal•14h ago•202 comments

Show HN: ResolveHQ – A Helpdesk Built on Cloudflare Workers, D1, R2 and Queues

https://github.com/mirza-rizvi/ResolveHQ
57•mirza_rizvi•11h ago•18 comments

Rune is now open source

https://rune.build/blog/rune-is-now-open-source
184•ernestrc•18h ago•58 comments

Λ Snap – An inviting programming language for kids and adults for CS study

https://snap.berkeley.edu/
143•dr_kiszonka•16h ago•82 comments

AlphaGenome maps 9B DNA variants

https://spectrum.ieee.org/alphagenome-atlas
85•ltononro•2d ago•7 comments

Testing Race Conditions

https://projectzero.google/2026/09/maccconc-race-condition.html
50•alpaylan•2d ago•2 comments

The EPA is planning to scrap public review rules for data center pollution

https://capitalbnews.org/data-centers-permit-rules-epa/
461•doener•15h ago•330 comments

Google will buy half the electricity from one of Finland's nuclear power plants

https://www.bbc.com/news/articles/c8r6y4me2g6o
360•lukaspetersson•1d ago•322 comments

Another way to leak traffic on Android has been discovered

https://mullvad.net/en/blog/another-way-to-leak-traffic-on-android-has-been-discovered
66•mhitza•12h ago•7 comments

Claude is only available to people over 18 years

https://support.claude.com/en/articles/15171100-age-assurance-on-claude
641•Muhammad523•22h ago•627 comments

RTK reports token savings, but our cost benchmarks disagree

https://quesma.com/blog/does-rtk-make-ai-coding-cheaper/
162•michalwarda•22h ago•80 comments