@noelwelsh.bsky.social
Thoughts on the Cloudflare incident [1] from a PL perspective.
Some file had an implicit limit of 200 lines. If this could be typed checked that would be great. Types are cheap and prevent all instances of a problem.
[1]: blog.cloudflare.com/18-november-...
Some file had an implicit limit of 200 lines. If this could be typed checked that would be great. Types are cheap and prevent all instances of a problem.
[1]: blog.cloudflare.com/18-november-...
Cloudflare outage on November 18, 2025
Cloudflare suffered a service outage on November 18, 2025. The outage was triggered by a bug in generation logic for a Bot Management feature file causing many Cloudflare services to be affected.
blog.cloudflare.com
November 19, 2025 at 12:08 PM
Thoughts on the Cloudflare incident [1] from a PL perspective.
Some file had an implicit limit of 200 lines. If this could be typed checked that would be great. Types are cheap and prevent all instances of a problem.
[1]: blog.cloudflare.com/18-november-...
Some file had an implicit limit of 200 lines. If this could be typed checked that would be great. Types are cheap and prevent all instances of a problem.
[1]: blog.cloudflare.com/18-november-...
XML as syntax for a programming language was a bad idea in Ant back in the early 2000s, and it's still a bad idea in the CSL I'm working on now.
(Same thing applies to YAML, modulo changing the years.)
(Same thing applies to YAML, modulo changing the years.)
November 19, 2025 at 10:51 AM
XML as syntax for a programming language was a bad idea in Ant back in the early 2000s, and it's still a bad idea in the CSL I'm working on now.
(Same thing applies to YAML, modulo changing the years.)
(Same thing applies to YAML, modulo changing the years.)
After fixing up a bunch of citations (DBLP saved me with the ACM being unusable due to the Cloudflare incident) I think I can make the Typst version of Functional Programming Strategies live, replacing the older Latex version. I'll never use Latex again if I can help it. Another win for FP! 😆
November 18, 2025 at 2:17 PM
After fixing up a bunch of citations (DBLP saved me with the ACM being unusable due to the Cloudflare incident) I think I can make the Typst version of Functional Programming Strategies live, replacing the older Latex version. I'll never use Latex again if I can help it. Another win for FP! 😆
Reworking some of the bibliographical notes in Functional Programming Strategies, and I discovered that regular expression derivatives are behind the current .NET regex engine, and a best-in-class Rust engine!
E.g. dl.acm.org/doi/pdf/10.1...
It's nice when theory matches up with practice. 😁
E.g. dl.acm.org/doi/pdf/10.1...
It's nice when theory matches up with practice. 😁
dl.acm.org
November 18, 2025 at 1:14 PM
Reworking some of the bibliographical notes in Functional Programming Strategies, and I discovered that regular expression derivatives are behind the current .NET regex engine, and a best-in-class Rust engine!
E.g. dl.acm.org/doi/pdf/10.1...
It's nice when theory matches up with practice. 😁
E.g. dl.acm.org/doi/pdf/10.1...
It's nice when theory matches up with practice. 😁
Judging by the errors I'm seeing across the Internet, can we now say CloudFlare is the new AWS?
November 18, 2025 at 12:51 PM
Judging by the errors I'm seeing across the Internet, can we now say CloudFlare is the new AWS?
Reposted
Our next #Scala #OpenSource Hack Night on Nov 19th (Wed) will be held at Medidata, starting at 6pm!
Come and enjoy a night of fun hacking & learning!
Sign up here: 🌟
www.meetup.com/london-scala...
Come and enjoy a night of fun hacking & learning!
Sign up here: 🌟
www.meetup.com/london-scala...
Scala Open Source Hack Night @ Medidata!, Wed, Nov 19, 2025, 6:00 PM | Meetup
Calling all Scala enthusiasts! Join us for a fun night of hacking, collaborating, and contributing to open-source projects. Whether you’re a seasoned Scala developer or jus
www.meetup.com
November 16, 2025 at 11:24 AM
Our next #Scala #OpenSource Hack Night on Nov 19th (Wed) will be held at Medidata, starting at 6pm!
Come and enjoy a night of fun hacking & learning!
Sign up here: 🌟
www.meetup.com/london-scala...
Come and enjoy a night of fun hacking & learning!
Sign up here: 🌟
www.meetup.com/london-scala...
Finished updating the applicatives chapter in Functional Programming Strategies[1], meaning one chapter left to complete the migration from Latex to Typst[2]. Only a few chapters of content to go before the book is complete!
[1]: scalawithcats.com
[2]: Complete enough to publish a draft.
[1]: scalawithcats.com
[2]: Complete enough to publish a draft.
Functional Programming Strategies in Scala with Cats
scalawithcats.com
November 14, 2025 at 2:45 PM
Finished updating the applicatives chapter in Functional Programming Strategies[1], meaning one chapter left to complete the migration from Latex to Typst[2]. Only a few chapters of content to go before the book is complete!
[1]: scalawithcats.com
[2]: Complete enough to publish a draft.
[1]: scalawithcats.com
[2]: Complete enough to publish a draft.
Struth! As if it wasn't hard enough dodging the venomous snakes, the venomous spiders, the venomous fish, the venomous octopi, the Great Whites, and the drop bears, ancient Aussies also had to dodge drop crocs! www.bbc.co.uk/news/article...
Evidence of ancient tree-climbing 'drop crocs' found in Australia
Scientists say the crocodiles hunted like leopards by climbing trees and killing prey below.
www.bbc.co.uk
November 12, 2025 at 6:59 PM
Struth! As if it wasn't hard enough dodging the venomous snakes, the venomous spiders, the venomous fish, the venomous octopi, the Great Whites, and the drop bears, ancient Aussies also had to dodge drop crocs! www.bbc.co.uk/news/article...
What in the SML?! I find myself again writing code that uses self types (and type refinements!) to compose modules of code.
A few years ago I would have said this was very esoteric. I still think it's very esoteric, but also useful! But why? What's the underlying pattern?
A few years ago I would have said this was very esoteric. I still think it's very esoteric, but also useful! But why? What's the underlying pattern?
November 7, 2025 at 11:36 AM
What in the SML?! I find myself again writing code that uses self types (and type refinements!) to compose modules of code.
A few years ago I would have said this was very esoteric. I still think it's very esoteric, but also useful! But why? What's the underlying pattern?
A few years ago I would have said this was very esoteric. I still think it's very esoteric, but also useful! But why? What's the underlying pattern?
Saw a few posts today about restrictive open source licenses. Some prevent competition (e.g. Elastic License). Others prevent people in certain industries from using the software (e.g. military) Summarized, the posts were "OMG, why are you forcing your politics on me". This is a stupid take.
November 6, 2025 at 3:05 PM
Saw a few posts today about restrictive open source licenses. Some prevent competition (e.g. Elastic License). Others prevent people in certain industries from using the software (e.g. military) Summarized, the posts were "OMG, why are you forcing your politics on me". This is a stupid take.
Reposted
Our next Scala Talks event is happening on Nov 12 (Wed) at Depop!
We have some international speakers!
Agnès Cardin will share her experience publishing a Scala book, and Maciej Gorywoda will show us how Jetbrain's AI tools can help you write Scala!
Sign up here:
www.meetup.com/london-scala...
We have some international speakers!
Agnès Cardin will share her experience publishing a Scala book, and Maciej Gorywoda will show us how Jetbrain's AI tools can help you write Scala!
Sign up here:
www.meetup.com/london-scala...
Scala Talks: Write a book about Scala during Covid & AI tooling for developers, Wed, Nov 12, 2025, 6:00 PM | Meetup
🎉 Come along to the London Scala Talks! 🎉
In this event you'll hear from Agnès Cardin and Maciej Gorywoda.
**Agenda**
6:00pm - 🥤 Doors open. Come along and grab a drink
www.meetup.com
November 5, 2025 at 10:13 PM
Our next Scala Talks event is happening on Nov 12 (Wed) at Depop!
We have some international speakers!
Agnès Cardin will share her experience publishing a Scala book, and Maciej Gorywoda will show us how Jetbrain's AI tools can help you write Scala!
Sign up here:
www.meetup.com/london-scala...
We have some international speakers!
Agnès Cardin will share her experience publishing a Scala book, and Maciej Gorywoda will show us how Jetbrain's AI tools can help you write Scala!
Sign up here:
www.meetup.com/london-scala...
After reading old programming language papers, I feel obligated to report that Miranda is a trademark of Research Software Limited.
November 5, 2025 at 11:03 AM
After reading old programming language papers, I feel obligated to report that Miranda is a trademark of Research Software Limited.
Reposted
Does JavaScript….go hard?!??
October 24, 2025 at 5:54 AM
Does JavaScript….go hard?!??
Amazing what a few years of experience does. Just simplified some fs2 + Cats Effect code into about 1/3 the number of lines of just fs2 code. The increased clarity in the code reflects the increased clarity in my head over the approximately 6 years since I started that code.
October 16, 2025 at 3:39 PM
Amazing what a few years of experience does. Just simplified some fs2 + Cats Effect code into about 1/3 the number of lines of just fs2 code. The increased clarity in the code reflects the increased clarity in my head over the approximately 6 years since I started that code.
Staging is the number one PL feature I'd like to see move from academia to industry. For example, configuration / dependency injection is vastly simplified with staging. There are limited forms in some current languages (e.g. comptime in Zig) but they aren't sufficiently expressive.
October 15, 2025 at 6:56 PM
Staging is the number one PL feature I'd like to see move from academia to industry. For example, configuration / dependency injection is vastly simplified with staging. There are limited forms in some current languages (e.g. comptime in Zig) but they aren't sufficiently expressive.
What's the best file watcher in Scala? So far I've found:
- sbt. Not sure about using sbt as a library dependency.
- Play. Should be well tested, but maybe old?
- fs2. Documented to the usual fs2 standard (i.e. not at all) but should integrate with the CE codebase
Any thoughts?
- sbt. Not sure about using sbt as a library dependency.
- Play. Should be well tested, but maybe old?
- fs2. Documented to the usual fs2 standard (i.e. not at all) but should integrate with the CE codebase
Any thoughts?
October 15, 2025 at 6:17 PM
What's the best file watcher in Scala? So far I've found:
- sbt. Not sure about using sbt as a library dependency.
- Play. Should be well tested, but maybe old?
- fs2. Documented to the usual fs2 standard (i.e. not at all) but should integrate with the CE codebase
Any thoughts?
- sbt. Not sure about using sbt as a library dependency.
- Play. Should be well tested, but maybe old?
- fs2. Documented to the usual fs2 standard (i.e. not at all) but should integrate with the CE codebase
Any thoughts?
I'm only 6 chapters into Katabasis, but so far it is a heck of a lot of fun. I think anyone who has been involved in academia will enjoy. How could you not enjoy a story whose premise is two graduate students' journey into hell to rescue their advisor?
October 15, 2025 at 6:08 PM
I'm only 6 chapters into Katabasis, but so far it is a heck of a lot of fun. I think anyone who has been involved in academia will enjoy. How could you not enjoy a story whose premise is two graduate students' journey into hell to rescue their advisor?
For the last year or two, most of the books I've "read" have been audiobooks. Spotify has a good selection, and it's easy to squeeze an hour or so of listening into the day, when doing chores, or exercise that doesn't involve too much movement. Not all books work this way, but it's good for many.
October 15, 2025 at 6:05 PM
For the last year or two, most of the books I've "read" have been audiobooks. Spotify has a good selection, and it's easy to squeeze an hour or so of listening into the day, when doing chores, or exercise that doesn't involve too much movement. Not all books work this way, but it's good for many.
Reposted
The term "vibe coding" raises an important question: what exactly is coding? In my last newsletter I argue that coding is very narrowly defined, as just getting ideas already crystal clear in your brain into source code.
October 9, 2025 at 9:15 AM
The term "vibe coding" raises an important question: what exactly is coding? In my last newsletter I argue that coding is very narrowly defined, as just getting ideas already crystal clear in your brain into source code.
Reposted
October 8, 2025 at 11:23 AM
Reposted
A reminder that Scalabridge London is back on from tomorrow! A truly great opportunity to get to know amazing people and work on interesting projects to master Scala and functional programming!
Sign up here if you want to join us: www.meetup.com/scalabridge-...
Sign up here if you want to join us: www.meetup.com/scalabridge-...
ScalaBridge Autumn 2025 Start!, Wed, Oct 8, 2025, 6:00 PM | Meetup
ScalaBridge London is back for Autumn 2025. Our first session is hosted by the lovely people at SiriusXM, a long time host of ours.
A big change with the new term is the s
www.meetup.com
October 7, 2025 at 9:55 AM
A reminder that Scalabridge London is back on from tomorrow! A truly great opportunity to get to know amazing people and work on interesting projects to master Scala and functional programming!
Sign up here if you want to join us: www.meetup.com/scalabridge-...
Sign up here if you want to join us: www.meetup.com/scalabridge-...
A few years back some companies banned "politics at work". There is no useful definition of politics that excludes normal workplace activities, so this ban is simply a hammer that those with power can arbitrarily deploy against those without.
This is the same, but on a much wider scale.
This is the same, but on a much wider scale.
The Compact says "Signatories commit... to transforming or abolishing institutional units that purposefully punish, belittle, and even spark violence against conservative ideas."
What does this mean for units teaching evolution, history, or climate change?
www.washingtonexaminer.com/wp-content/u...
What does this mean for units teaching evolution, history, or climate change?
www.washingtonexaminer.com/wp-content/u...
October 2, 2025 at 5:00 PM
A few years back some companies banned "politics at work". There is no useful definition of politics that excludes normal workplace activities, so this ban is simply a hammer that those with power can arbitrarily deploy against those without.
This is the same, but on a much wider scale.
This is the same, but on a much wider scale.
Reposted
3/ Tech fascism in a nutshell: “Computers are so much more rule-based, controllable, fixable, and comprehensible than any human will ever be. As many political schools of thought do, these technolibertarians make a philosophy out of a personality defect.“ She wrote this in 2000!
September 24, 2025 at 6:36 PM
3/ Tech fascism in a nutshell: “Computers are so much more rule-based, controllable, fixable, and comprehensible than any human will ever be. As many political schools of thought do, these technolibertarians make a philosophy out of a personality defect.“ She wrote this in 2000!
😍 Extremely cool: a DSL for knitting patterns: t0mpr1c3.github.io/knotty/index...
Implemented, of course, in Racket.
I love the idea of an OSS standard for knitting patterns. I also love the idea of little programming languages, produced without fuss to make life better for humans.
🧶
Implemented, of course, in Racket.
I love the idea of an OSS standard for knitting patterns. I also love the idea of little programming languages, produced without fuss to make life better for humans.
🧶
Knotty
t0mpr1c3.github.io
September 25, 2025 at 8:58 AM
😍 Extremely cool: a DSL for knitting patterns: t0mpr1c3.github.io/knotty/index...
Implemented, of course, in Racket.
I love the idea of an OSS standard for knitting patterns. I also love the idea of little programming languages, produced without fuss to make life better for humans.
🧶
Implemented, of course, in Racket.
I love the idea of an OSS standard for knitting patterns. I also love the idea of little programming languages, produced without fuss to make life better for humans.
🧶
@scalabridgelondon.bsky.social is back in October! Here's the projects we'll be working on:
www.scalabridgelondon.org/projects/
Sign up for your choice here:
docs.google.com/forms/d/e/1F...
(All the details and much more on our website www.scalabridgelondon.org)
www.scalabridgelondon.org/projects/
Sign up for your choice here:
docs.google.com/forms/d/e/1F...
(All the details and much more on our website www.scalabridgelondon.org)
Learn or improve at programming in a fun and supportive environment
www.scalabridgelondon.org
September 22, 2025 at 4:13 PM
@scalabridgelondon.bsky.social is back in October! Here's the projects we'll be working on:
www.scalabridgelondon.org/projects/
Sign up for your choice here:
docs.google.com/forms/d/e/1F...
(All the details and much more on our website www.scalabridgelondon.org)
www.scalabridgelondon.org/projects/
Sign up for your choice here:
docs.google.com/forms/d/e/1F...
(All the details and much more on our website www.scalabridgelondon.org)