David Allsopp

David Allsopp

@dra27.uk

Cambridge-based, London-working software engineer; sometime classical singer. @dra27 in many places, including GitHub; OCaml maintainer; opam maintainer; Windows {apolog,evangel}ist

253 followers60 following80 posts

David Allsopp
@dra27.uk

I was implicitly referred to as a “hoary greybeard” the other day… my son just innocently asked how long I’ve worked on/in OCaml and I realised the answer is half my life 👴🏻 #old #greybeard

David Allsopp
@dra27.uk

Haven’t had to use a paper train ticket in a looong time, and was somewhat bemused to see the machine list that it would be printing two seat reservations. I am duly sat in my first non-specific seat of the day. Nice paper-saving there, @greateranglia.bsky.social!

David Allsopp
@dra27.uk

Of course, only have a paper ticket at all because apparently issuing an electronic ticket which can work both mainline station barriers and London Underground barriers is a feat engineering well beyond our national infrastructure…

David Allsopp
@dra27.uk

Unsure whether to be more shocked by the discovery that there will be 10 current/former lay clerks singing at this morning’s mass at Westminster Cathedral (first time for a decade?) or that they’ve completely renovated the 100 year old song school toilets!

David Allsopp
@dra27.uk

3 years since I finalised the demo of it for the OCaml Workshop in Ljubljana, Relocatable OCaml is finally submitted for review! 🥳🍾🎊

David Allsopp
@dra27.uk

Currently dotting ‘i’s and crossing ‘t’s and therefore wishing I’d used fewer ‘i’s and ‘t’s in my code (also, when I did I start handwriting code?? 🤔) #relocatable #ocaml

David Allsopp
@dra27.uk

Wonders how much water Apple could save each year by having Apple Mail offer to reduce the size of photos being emailed from an iPad in the same way as it does on an iPhone? 🤔🧐🤫

David Allsopp
@dra27.uk

“I do not know whether there is anything peculiarly exciting in the air of this particular part of Hertfordshire, but the number of engagements that go on seems to me considerably above the proper average that statistics have laid down for our guidance.” Good old Oscar 🤣

David Allsopp
@dra27.uk

Congratulations to Apple for anticlimax of the month with Apple “Intelligence”. In a metaphor for the age, seems all the time has been spent on the animations and hype and not a lot on it actually doing anything 🤷🏻‍♂️ #unabletosummarisethismessage

David Allsopp reposted

Yaron Minsky
@yminsky.bsky.social

Yet another small OCaml/OxCaml diff has been squished! Polymorphic parameters has just gotten merged upstream: github.com/ocaml/ocaml/... There's more to go (include functor, for example: github.com/ocaml/RFCs/p...), but it's nice to see more progress in this space.

github.comPolymorphic Parameters by voodoos · Pull Request #13806 · ocaml/ocamlThis upstreaming PR adds the possibility to have function parameters with polymorphic types in the language. This work was originally done by @lpw25 in Jane Street's fork of the compiler with e...
David Allsopp
@dra27.uk

Testing opam packages for Relocatable OCaml which actually take advantage of it. Creating a new switch using the same version as one you've already built in another switch now takes 5 seconds, rather than 2 minutes (cloning the compiler itself takes just 100ms of that 5 seconds!)

David Allsopp reposted

Yaron Minsky
@yminsky.bsky.social

I'm pleased to announce OxCaml! OxCaml is Jane Street's branch of OCaml. We've given it a new name and a snazzy logo, and done a bunch of work to make it easy for people to try.

David Allsopp
@dra27.uk

1994 (and earlier): select text in one “app”, copy, paste to another “app” 2025: select text in one app, copy, switch to other app and discover they’ve disabled paste on the input fields. Return to other app. Write information on piece of paper. Type into other app. #progress #modern

David Allsopp
@dra27.uk

Fell through a wormhole and sang the Solemn Passion + traditional Tallis Lamentations at Westminster Cathedral today. Realised the last time I did that was 17 years ago 🥺😳👴🏻

David Allsopp
@dra27.uk

Wondering if this is a judging stare about the delays getting Relocatable OCaml’s first pull request opened, or possibly something else… 🐈‍⬛ #catcaml

David Allsopp
@dra27.uk

Possibly using them gratuitously, but I’m liking OCaml 5.4’s labelled tuples for logic setting up predicates. Nice to avoid stuff like let p1, p2, (* … *) = if (* something *) then (true, false, false, true, true) else if (* … *) but without the weight of having to declare a record #ocaml

David Allsopp
@dra27.uk

Initial idea - July 2019 Design proposal (before any code! 😇) - November 2019 Initial prototype - September 2021 Working prototype - September 2022 Candidate implementation - April 2025 #RAD 🫣

github.comRelocatable OCaml by dra27 · Pull Request #53 · ocaml/RFCsRendered version. The first proof-of-concept of this work was presented at OCaml Workshop 2022. The OCaml compiler distribution requires the Standard Library to be stored in a fixed location, speci...
David Allsopp
@dra27.uk

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

David Allsopp
@dra27.uk

Love this - especially the last line 😂 - but particularly because while doing something else in the OCaml runtime this week, I did scroll by and briefly pause on one of the (doubly) linked lists in the runtime’s memory allocator 🥸🤣

Alberta Tech@albertatech.bsky.social

Linked lists aren’t real.