iiinova — where your digital self keeps evolving

Reposted by Jan Midtgaard

David Ho @davidho.bsky.social · 04/05/2025

I think a lot about what Carl Sagan said in one of his final interviews.

"WE'VE ARRANGED A society based on science and technology, in which nobody understands anything about science technology. And this combustible mixture of ignorance and power, sooner or later, is going to blow up in our faces. Who is running the science and technology in a democracy if the people don't know anything about it?"
"Science is more than a body of knowledge, it's a way of thinking. A way of skeptically interrogating the universe with a fine understanding of human fallibility. If we are not able to ask skeptical questions, to interrogate those who tell us that something is true, to be skeptical of those in authority, then we're up for grabs for the next charlatan, political or religious, who comes ambling along."

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Jan Midtgaard @janmidtgaard.bsky.social · 02/07/2025

Congratulations Prof. Ron! 😃👏

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Reposted by Jan Midtgaard

Yaron Minsky @yminsky.bsky.social · 24/06/2025

A gem from Stephen Dolan, which proposes replacing the "generational hypothesis" that drives the design of generational GCs with a notion of lifetime dispersion as measured by the gini coefficient. Nice to see economics playing a role here! dl.acm.org/doi/pdf/10.1...

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Jan Midtgaard @janmidtgaard.bsky.social · 08/05/2025

Last night it was announced that our TACAS-paper 'Dynamic Verification of OCaml Software with Gospel and Ortac/QCheck-STM' co-authored with Nikolaus Huber, Naomi Spargo, Nicolas Osborne, and Samuel Hym won the 2025 @etapsconf.bsky.social's Best Tool Paper Award 🎉 #testing #pbt #award

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Noah Shachtman @noahshachtman.bsky.social · 07/05/2025

There are people I know in the national security community who are terrified that the US government is sleepwalking into a 9/11-level catastrophe. Focusing finite resources on nonsense like this instead of credible threats -- that is the reason they're so worried. www.wsj.com/world/greenl...

wsj.com

Exclusive | U.S. Orders Intelligence Agencies to Step Up Spying on Greenland

The push underscores the seriousness of President Trump’s intent to acquire the island from Denmark.

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Reposted by Jan Midtgaard

Martin Janiczek @janiczek.cz · 01/05/2025

A blogpost I wrote on elm-test's Test.Distribution - testing whether your fuzzers generate interesting cases often enough! martin.janiczek.cz/2025/05/01/e...

martin.janiczek.cz

Elm test distributions

…in which I’ll tell you how you can make sure your property based tests are testing the interesting cases.

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Reposted by Jan Midtgaard

Gro-Tsen @gro-tsen.bsky.social · 07/04/2025

This video was posted on Twitter by the official account of the People's Republic of China's embassy in the United States. The Chinese Communist Party is lecturing the US Republican President by using a Reagan speech on the importance of free trade. We are really living in the Weird timeline.

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Jan Midtgaard @janmidtgaard.bsky.social · 04/04/2025

...and the award for best exception name showing up in an opam-repo CI run goes to... 🏆😄

CI log error message that has a red cross and the text "pyml.20210924 (failed: Great)"

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Reposted by Jan Midtgaard

Marcello Seri @mseri.me · 26/03/2025

≪We estimate the supply-side value of widely-used OSS is $4.15 billion, but that the demand-side value is much larger at $8.8 trillion. We find that firms would need to spend 3.5 times more on software than they currently do if OSS did not exist.≫ From www.hbs.edu/faculty/Page... #opensource

hbs.edu

The Value of Open Source Software - Working Paper - Faculty & Research - Harvard Business School

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New Nomads @new-nomads.com · 24/03/2025

Just... have... to drop this... here.

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KC Sivaramakrishnan @kcsrk.info · 14/03/2025

If all goes well, OCaml 5 code will ride into space in < 24 hrs. www.dphispace.com/post/parsimo...

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Jan Midtgaard @janmidtgaard.bsky.social · 12/03/2025

> We have been using OCaml 5 in production since the middle of February 2025, and the rollout has been entirely uneventful. This was a highlight for me, after having worked to stress test it over the past ~3 years. There are other nuggets in @semgrep.bsky.social's latest blog post though... 🤓

semgrep.dev

Semgrep | Upgrading Semgrep from OCaml 4 to OCaml 5

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Reposted by Jan Midtgaard

KC Sivaramakrishnan @kcsrk.info · 10/03/2025

Great work from @tarides.com folks on pragmatic verification of OCaml software. Chosen as one of the distinguished papers at TACAS 2025. Paper: janmidtgaard.dk/papers/Huber... Code: discuss.ocaml.org/t/ann-ortac-...

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Jan Midtgaard @janmidtgaard.bsky.social · 05/03/2025

github.com/ocaml/opam-r... uses github.com/ocaml/opam-r... which uses github.com/ocaml/opam-r... which seem to be supported on Windows. The status page is green for one of 4.14 or 5.3 on each. Which OCaml version are you using - you didn't say?

github.com

opam-repository/packages/caqti-driver-postgresql/caqti-driver-postgresql.2.1.2/opam at master · ocaml/opam-repository

Main public package repository for opam, the source package manager of OCaml. - ocaml/opam-repository

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Jan Midtgaard @janmidtgaard.bsky.social · 05/03/2025

Also: Beware that not all packages may work out of the box on Windows, as they tends to require C code and libraries at some point, and setting that up may require fiddling with conf-* files on the opam repository. Caqti should however run on Windows, it seems from windows.check.ci.dev

windows.check.ci.dev

opam-health-check

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Jan Midtgaard @janmidtgaard.bsky.social · 05/03/2025

From the error message, it sounds like an error while trying to use postgresql with Caqti. If that's the case, I would try to cut out 'dream' and see if a simple 5-10-line OCaml program can connect with such a database through Caqti.

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Jan Midtgaard @janmidtgaard.bsky.social · 05/03/2025

OK. If I'm understanding the above page correctly, this means you got a MinGW installation of the compiler (it's the default). It is handy to know, to understand the problem and when searching, e.g., Google or Discuss for someone else with a similar problem.

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Jan Midtgaard @janmidtgaard.bsky.social · 04/03/2025

Yep 👍 How did you install OCaml under Windows? ocaml.org/docs/ocaml-o... lists some of the variants I mentioned above.

ocaml.org

OCaml on Windows · OCaml Documentation

Read about the state of OCaml on Windows and our roadmap to improve Windows support.

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Jan Midtgaard @janmidtgaard.bsky.social · 04/03/2025

For the latter I would probably use the `nm` tool on Linux.

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Jan Midtgaard @janmidtgaard.bsky.social · 04/03/2025

3. You are getting a linking error. This means the compiler(s) translated each file, but failed in the last part stitching them together based on names. Here it fails to resolve a bunch of names listed in the error. Have you checked that the mentioned file(s) exist - and that they contain the names?

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Jan Midtgaard @janmidtgaard.bsky.social · 04/03/2025

2. You are sharing an error message - but not much about the code that trigger it. Generally it helps to create and share a small reproducer. From such a thing, I sometimes end up figuring out the problem myself...

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Jan Midtgaard @janmidtgaard.bsky.social · 04/03/2025

I don't have the answer for you, so here's some general advice: 1. Your post is too short on detail. For one, OCaml can run in at last 4 ways on Windows (MinGW, Cygwin, MSVC, WSL, ...). Which one are you using?

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David Allsopp @dra27.uk · 01/03/2025

Finally - Relocatable OCaml in “fully relocatable” mode is also reproducible (as long as the C compiler is reproducible) and passes its testsuite 😮‍💨🥳🎉🍾🎊

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Jan Midtgaard @janmidtgaard.bsky.social · 24/02/2025

Using a tuple-comma with right-to-left evaluation seems a distraction. Is that intentionally or did it get mixed up with the single ; sequence operator? ocaml.org/docs/mutabil...

ocaml.org

Mutability and Imperative Control Flow · OCaml Documentation

Write stateful programs in OCaml. Use for and while loops, if-then-else, mutable record fields, and references.

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Jan Midtgaard @janmidtgaard.bsky.social · 19/02/2025

OK, but that does something with a worse complexity. In your gist, List.mem is going to take O(n) time, and you are calling it for each row * col. I'm suggesting something like dropping `|> PosSet.of_list` and replacing `PosSet.iter` with `List.iter`, thus taking only 1 pass over the list 🙂

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Jan Midtgaard @janmidtgaard.bsky.social · 19/02/2025

After a quick look at that code, you seem to only use PosSet in part2, where the set is represented as a list, then transformed into a set only to iterate over it. Unless this is a bottleneck, I would probably just keep the list as is and iterate over that directly... 🤔🤷

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Jan Midtgaard @janmidtgaard.bsky.social · 19/02/2025

If your use case is something involving integers, you might consider Patricia trees, a functional and fast bit-walking trie-like data structure: github.com/backtracking... codex.top/api/patricia...

github.com

GitHub - backtracking/ptset: Integer set implementation using Patricia trees

Integer set implementation using Patricia trees. Contribute to backtracking/ptset development by creating an account on GitHub.

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Jan Midtgaard @janmidtgaard.bsky.social · 19/02/2025

In OCaml's Stdlib sets are represented as balanced search trees: github.com/ocaml/ocaml/... The answer is therefore "it depends". For many uses assuming no/few collisions hashtables are going to be fast. Worst case, however probing may end up spending O(n) time. Sets offer a worst case of O(log n).

github.com

ocaml/stdlib/set.ml at trunk · ocaml/ocaml

The core OCaml system: compilers, runtime system, base libraries - ocaml/ocaml

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Jan Midtgaard @janmidtgaard.bsky.social · 18/02/2025

Thanks for the kind words Sabine 🙏☺️

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Jan Midtgaard @janmidtgaard.bsky.social · 18/02/2025

The future is still up in the air. I've been taking a break to hack on a couple of open source things and to go skiing with the family over the winter holidays. ⛷️ Feel free to shoot me a PM if you want to meet, catch up, and chat over a coffee ☕ 🙂

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Jan Midtgaard @janmidtgaard.bsky.social · 18/02/2025

Dear all After a bit over 3 years my contract with Tarides has come to an end. It has been great - working with and being team lead for an exceptional group of software engineers and - applying my property-based testing skills to stress test and help get the multicore OCaml5 runtime+stdlib in shape.

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Jan Midtgaard @janmidtgaard.bsky.social · 14/02/2025

Raphaël Monat has a PhD position open to work on static analysis with him at Inria in Lille 🙂 recrutement.inria.fr/public/class... #phd-position #abstract-interpretation #static-analysis #ocaml

recrutement.inria.fr

PhD Position F/M Resource-Aware Conservative Static Analysis

Offre d'emploi Inria

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Jan Midtgaard @janmidtgaard.bsky.social · 06/02/2025

Beautiful morning in Aarhus for a morning dip with 4C water and 3C air ☀️🌊🤓

A bright February sunrise over a point where the sea meets a slim sand beach with a forest of naked trees close by.

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Jan Midtgaard @janmidtgaard.bsky.social · 05/02/2025

QCheck(2) hacking continues: 💻 github.com/c-cube/qchec... Replacing an RNG split hack with faster, gastly Obj.magic one, QCheck2 on OCaml 4 starts to work reasonably 🤓 #ocaml #quickcheck #pbt

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Reposted by Jan Midtgaard

ading.dev @ading.dev · 31/01/2025

I got Linux running in a PDF file using a RISC-V emulator. PDFs support Javascript, so Emscripten is used to compile the TinyEMU emulator to asm.js, which runs in the PDF. It boots in about 30 seconds and emulates a riscv32 buildroot system. linux.doompdf.dev/linux.pdf github.com/ading2210/li...

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Brian Phillips @brianphillips.lol · 30/01/2025

If you wanted no leaks you should have gone into Settings -> Security -> Configure privacy & security -> Privacy options -> Other -> Configure -> Media interface and clicked “Disallow.” The Leak setting is on by default but we understand your privacy is important so we’ve made it easy to opt out

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Reposted by Jan Midtgaard

Yaron Minsky @yminsky.bsky.social · 30/01/2025

A post about the long and winding road that lead to the Dune build system for OCaml, and, eventually, to Dune replacing our old internal build system, Jenga. blog.janestreet.com/how-we-accid...

blog.janestreet.com

How we accidentally built a better build system for OCaml

A “build system” is one of the most important tools in a developer’stoolbox. Roughly, it figures out how to create runnable programs froma bunch of different...

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Jan Midtgaard @janmidtgaard.bsky.social · 23/01/2025

Yep 👍 It reminds me (again) of steps 1 and 2 of this nice, pedagogical paper that I was academically raised with: citeseerx.ist.psu.edu/document?rep... As a result, I tend to just read these as "named in either prefix or postfix notation"... 🤓

citeseerx.ist.psu.edu

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Jan Midtgaard @janmidtgaard.bsky.social · 23/01/2025

You are however introducing a data dependency, which I believe corresponds to an eta-expansion in a desugared version. These should align: ``` (* Prints hello after world *) let _ = f "hello" () >>= fun u -> f "world" u (* Prints world after hello *) let _ = let* u = f "hello" () in f "world" u ```

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Jan Midtgaard @janmidtgaard.bsky.social · 23/01/2025

This is just the good old right-to-left evaluation issue surprising for the N+1'th time, isn't it? 🤔 Recall that despite its syntax, >>= is just a 2-argument function call to bind underneath the hood, which are most likely evaluated right-to-left, but with evaluation order technically undefined.

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Jan Midtgaard @janmidtgaard.bsky.social · 18/01/2025

I don't think so. My friend is more into 3d-printing that FP... He happened to have a fair amount of excess orange ligaments after printing pumpkins for Halloween, and then thought of me 😄

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Jan Midtgaard @janmidtgaard.bsky.social · 18/01/2025

Yesterday a very good friend gave me this nice box of homemade OCaml coasters, all 3d-printed. Naturally, they were immediately put to good use... 😄🍻 #ocaml #fp

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xvw @xvw.lol · 17/01/2025

I'm really happy to present, with @tarides.com , #OCaml Eglot, an #Emacs (minor) mode for editing OCaml code, using LSP through Eglot, the built-in #LSP client of Emacs: github.com/tarides/ocam... Feedback, contribution and RT much appreciated

github.com

GitHub - tarides/ocaml-eglot: An overlay on Eglot for editing OCaml code using LSP

An overlay on Eglot for editing OCaml code using LSP - tarides/ocaml-eglot

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