Tomas Petricek
@tomasp.net
Assistant prof at @mff.unikarlova.cuni.cz. Interested in new ways of thinking about programming and history & philosophy of computing. Previously at University of Kent and @cst.cam.ac.uk.
We even had a web-based version of this so you could run the code in a web browser using Silverlight (!) tryjoinads.org
The web-based version built a bit later had a revised syntax and also added "let! .. and" for applicative functors.
The web-based version built a bit later had a revised syntax and also added "let! .. and" for applicative functors.
November 14, 2025 at 12:20 AM
We even had a web-based version of this so you could run the code in a web browser using Silverlight (!) tryjoinads.org
The web-based version built a bit later had a revised syntax and also added "let! .. and" for applicative functors.
The web-based version built a bit later had a revised syntax and also added "let! .. and" for applicative functors.
I worked on "match!" to #fsharp back in 2008/9 during an internship with @dsyme.bsky.social and parallel tasks was one example in my MSc thesis: tomasp.net/academic/the... (p. 78).
"match!" had the extra feature that you could do short-circuiting - so "_" means the task doesn't have to finish...
"match!" had the extra feature that you could do short-circuiting - so "_" means the task doesn't have to finish...
November 14, 2025 at 12:17 AM
I worked on "match!" to #fsharp back in 2008/9 during an internship with @dsyme.bsky.social and parallel tasks was one example in my MSc thesis: tomasp.net/academic/the... (p. 78).
"match!" had the extra feature that you could do short-circuiting - so "_" means the task doesn't have to finish...
"match!" had the extra feature that you could do short-circuiting - so "_" means the task doesn't have to finish...
F# 10 makes it possible to use let! .. and! to await two tasks in parallel. This brings back some memories!
November 14, 2025 at 12:13 AM
F# 10 makes it possible to use let! .. and! to await two tasks in parallel. This brings back some memories!
What if we think about proof assistants/dependently typed languages as interactive programming systems? Discussion today @mff.unikarlova.cuni.cz
(And yes, our building has fairly thick walls :-))
(And yes, our building has fairly thick walls :-))
November 10, 2025 at 10:27 AM
What if we think about proof assistants/dependently typed languages as interactive programming systems? Discussion today @mff.unikarlova.cuni.cz
(And yes, our building has fairly thick walls :-))
(And yes, our building has fairly thick walls :-))
Booked my train tickets for a trip to a PhD defense in Aarhus!
Maybe it's not faster than flying, but I get to go from a train station 10 minutes walk from where I live.
🚂👍
Maybe it's not faster than flying, but I get to go from a train station 10 minutes walk from where I live.
🚂👍
November 7, 2025 at 12:16 AM
Booked my train tickets for a trip to a PhD defense in Aarhus!
Maybe it's not faster than flying, but I get to go from a train station 10 minutes walk from where I live.
🚂👍
Maybe it's not faster than flying, but I get to go from a train station 10 minutes walk from where I live.
🚂👍
In the second lab of my Tiny Systems course, we write a small interactive BASIC interpreter, inspired by Commodore 64 (Dijkstra does not approve...)
🎞️Watch the videos on YouTube: www.youtube.com/watch?v=jR0m...
⌨️Get the source code here: github.com/tpetricek/ti...
🎞️Watch the videos on YouTube: www.youtube.com/watch?v=jR0m...
⌨️Get the source code here: github.com/tpetricek/ti...
October 20, 2025 at 9:18 AM
In the second lab of my Tiny Systems course, we write a small interactive BASIC interpreter, inspired by Commodore 64 (Dijkstra does not approve...)
🎞️Watch the videos on YouTube: www.youtube.com/watch?v=jR0m...
⌨️Get the source code here: github.com/tpetricek/ti...
🎞️Watch the videos on YouTube: www.youtube.com/watch?v=jR0m...
⌨️Get the source code here: github.com/tpetricek/ti...
I'm trying to replace my beloved but long-defunct Atom with VS Code for editing LaTeX.
How do I stop copilot from telling me that I can press "Ctrl+I"? I already disabled it using "github.copilot.enable", which hides the actual suggestions, but not this useless message...
How do I stop copilot from telling me that I can press "Ctrl+I"? I already disabled it using "github.copilot.enable", which hides the actual suggestions, but not this useless message...
October 11, 2025 at 2:17 PM
I'm trying to replace my beloved but long-defunct Atom with VS Code for editing LaTeX.
How do I stop copilot from telling me that I can press "Ctrl+I"? I already disabled it using "github.copilot.enable", which hides the actual suggestions, but not this useless message...
How do I stop copilot from telling me that I can press "Ctrl+I"? I already disabled it using "github.copilot.enable", which hides the actual suggestions, but not this useless message...
I just uploaded videos for the first lab of my tiny systems. TinyML - Write your own tiny functional language interpreter!
🎞️Watch the videos on YouTube: www.youtube.com/playlist?lis...
⌨️Get the source code here: github.com/tpetricek/ti...
🎞️Watch the videos on YouTube: www.youtube.com/playlist?lis...
⌨️Get the source code here: github.com/tpetricek/ti...
October 10, 2025 at 10:36 AM
I just uploaded videos for the first lab of my tiny systems. TinyML - Write your own tiny functional language interpreter!
🎞️Watch the videos on YouTube: www.youtube.com/playlist?lis...
⌨️Get the source code here: github.com/tpetricek/ti...
🎞️Watch the videos on YouTube: www.youtube.com/playlist?lis...
⌨️Get the source code here: github.com/tpetricek/ti...
I'm at #uist2025 presenting our new work with @jonathoda.bsky.social!
𝗗𝗲𝗻𝗶𝗰𝗲𝗸 is a computational substrate for end-user programming that makes it easy to implement programming experiences like programming by demonstration, collaborative editing and more!
tomasp.net/academic/pap...
𝗗𝗲𝗻𝗶𝗰𝗲𝗸 is a computational substrate for end-user programming that makes it easy to implement programming experiences like programming by demonstration, collaborative editing and more!
tomasp.net/academic/pap...
September 30, 2025 at 6:13 AM
I'm at #uist2025 presenting our new work with @jonathoda.bsky.social!
𝗗𝗲𝗻𝗶𝗰𝗲𝗸 is a computational substrate for end-user programming that makes it easy to implement programming experiences like programming by demonstration, collaborative editing and more!
tomasp.net/academic/pap...
𝗗𝗲𝗻𝗶𝗰𝗲𝗸 is a computational substrate for end-user programming that makes it easy to implement programming experiences like programming by demonstration, collaborative editing and more!
tomasp.net/academic/pap...
Slides from my talk "Critical Architecture/Software Theory" at PPIG 2025 in Belgrade: tpetricek.github.io/Talks/2025/c...
The talk has been a great excuse to organize some more ideas, on top of my earlier article on the topic: tomasp.net/architecture/
The talk has been a great excuse to organize some more ideas, on top of my earlier article on the topic: tomasp.net/architecture/
September 9, 2025 at 1:06 PM
Slides from my talk "Critical Architecture/Software Theory" at PPIG 2025 in Belgrade: tpetricek.github.io/Talks/2025/c...
The talk has been a great excuse to organize some more ideas, on top of my earlier article on the topic: tomasp.net/architecture/
The talk has been a great excuse to organize some more ideas, on top of my earlier article on the topic: tomasp.net/architecture/
Anybody remembers Microsoft script encoder? A true gem from the MSDN archives of August 1999: web.archive.org/web/20021214...
(The thing was clearly not very sophisticated: web.archive.org/web/20070103...)
(The thing was clearly not very sophisticated: web.archive.org/web/20070103...)
June 17, 2025 at 11:27 AM
Anybody remembers Microsoft script encoder? A true gem from the MSDN archives of August 1999: web.archive.org/web/20021214...
(The thing was clearly not very sophisticated: web.archive.org/web/20070103...)
(The thing was clearly not very sophisticated: web.archive.org/web/20070103...)
Organize Unlambda Days :-)
A conference for people who once talked about FP all the time, but do other interesting things today.
I'll come!
A conference for people who once talked about FP all the time, but do other interesting things today.
I'll come!
June 12, 2025 at 7:33 PM
Organize Unlambda Days :-)
A conference for people who once talked about FP all the time, but do other interesting things today.
I'll come!
A conference for people who once talked about FP all the time, but do other interesting things today.
I'll come!
The Choose-Your-Own-Adventure Calculus is a small formalism that captures an interaction pattern where you repeatedly choose from the available options.
Examples include type providers, structure editors, theorem provers & more!
Draft paper based on my earlier blog post: tomasp.net/academic/dra...
Examples include type providers, structure editors, theorem provers & more!
Draft paper based on my earlier blog post: tomasp.net/academic/dra...
June 10, 2025 at 12:34 PM
The Choose-Your-Own-Adventure Calculus is a small formalism that captures an interaction pattern where you repeatedly choose from the available options.
Examples include type providers, structure editors, theorem provers & more!
Draft paper based on my earlier blog post: tomasp.net/academic/dra...
Examples include type providers, structure editors, theorem provers & more!
Draft paper based on my earlier blog post: tomasp.net/academic/dra...
One last picture from @programming-conf.bsky.social!
A photo from the Friday afternoon visit to the Prague castle gardens, some time after we miraculously avoided the rain by hiding in a pub and talking about programming some more...
A photo from the Friday afternoon visit to the Prague castle gardens, some time after we miraculously avoided the rain by hiding in a pub and talking about programming some more...
June 9, 2025 at 7:54 PM
One last picture from @programming-conf.bsky.social!
A photo from the Friday afternoon visit to the Prague castle gardens, some time after we miraculously avoided the rain by hiding in a pub and talking about programming some more...
A photo from the Friday afternoon visit to the Prague castle gardens, some time after we miraculously avoided the rain by hiding in a pub and talking about programming some more...
Is schema change someone else's problem?
@jonathoda.bsky.social presenting our paper "Schema Evolution in Interactive Programming Systems" at @programming-conf.bsky.social Check it out: programming-journal.org/2025/9/2/
@jonathoda.bsky.social presenting our paper "Schema Evolution in Interactive Programming Systems" at @programming-conf.bsky.social Check it out: programming-journal.org/2025/9/2/
June 5, 2025 at 12:17 PM
Is schema change someone else's problem?
@jonathoda.bsky.social presenting our paper "Schema Evolution in Interactive Programming Systems" at @programming-conf.bsky.social Check it out: programming-journal.org/2025/9/2/
@jonathoda.bsky.social presenting our paper "Schema Evolution in Interactive Programming Systems" at @programming-conf.bsky.social Check it out: programming-journal.org/2025/9/2/
An interesting summary of envisioned use cases and things that people actually ended up doing:
June 5, 2025 at 8:02 AM
An interesting summary of envisioned use cases and things that people actually ended up doing:
On implementing languages based on their spec.
How it started: "Extending Python is easy if you know some C."
How it's going:
How it started: "Extending Python is easy if you know some C."
How it's going:
June 5, 2025 at 7:25 AM
On implementing languages based on their spec.
How it started: "Extending Python is easy if you know some C."
How it's going:
How it started: "Extending Python is easy if you know some C."
How it's going:
Fun fact from Thomas Würthinger's @programming-conf.bsky.social keynote. The most notable paper on GraalVM was published in Onward!
Maybe conference ranking is broken 😱?
Maybe conference ranking is broken 😱?
June 5, 2025 at 7:09 AM
Fun fact from Thomas Würthinger's @programming-conf.bsky.social keynote. The most notable paper on GraalVM was published in Onward!
Maybe conference ranking is broken 😱?
Maybe conference ranking is broken 😱?
I found the perfect illustration for the motivation behind our paper on schema change in programming systems - presented by @jonathoda.bsky.social at 25 next week: 2025.programming-conference.org/details/prog...
May 30, 2025 at 9:05 AM
I found the perfect illustration for the motivation behind our paper on schema change in programming systems - presented by @jonathoda.bsky.social at 25 next week: 2025.programming-conference.org/details/prog...
Do you want to write your own implementation of Tiny Boxer?
Check out my demo from PLISS'25 & follow the step-by-step tutorial here: github.com/tpetricek/ti...
Check out my demo from PLISS'25 & follow the step-by-step tutorial here: github.com/tpetricek/ti...
May 29, 2025 at 9:24 AM
Do you want to write your own implementation of Tiny Boxer?
Check out my demo from PLISS'25 & follow the step-by-step tutorial here: github.com/tpetricek/ti...
Check out my demo from PLISS'25 & follow the step-by-step tutorial here: github.com/tpetricek/ti...
Cannot make it to Prague for @programming-conf.bsky.social?
🎬 We will be streaming the keynotes, regular talks and MoreVMs workshop talks online!
👉 Keep an eye on: 2025.programming-conference.org
🎬 We will be streaming the keynotes, regular talks and MoreVMs workshop talks online!
👉 Keep an eye on: 2025.programming-conference.org
May 27, 2025 at 1:23 PM
Cannot make it to Prague for @programming-conf.bsky.social?
🎬 We will be streaming the keynotes, regular talks and MoreVMs workshop talks online!
👉 Keep an eye on: 2025.programming-conference.org
🎬 We will be streaming the keynotes, regular talks and MoreVMs workshop talks online!
👉 Keep an eye on: 2025.programming-conference.org
I'm speaking at Programming Language Implementation Summer School (PLISS) next week.
Let's see if I can get the attendees to implement a tiny version of Boxer: dl.acm.org/doi/pdf/10.1...
It is a fun example of how interactive programming *systems* can do more than *languages*!
Let's see if I can get the attendees to implement a tiny version of Boxer: dl.acm.org/doi/pdf/10.1...
It is a fun example of how interactive programming *systems* can do more than *languages*!
May 20, 2025 at 11:10 PM
I'm speaking at Programming Language Implementation Summer School (PLISS) next week.
Let's see if I can get the attendees to implement a tiny version of Boxer: dl.acm.org/doi/pdf/10.1...
It is a fun example of how interactive programming *systems* can do more than *languages*!
Let's see if I can get the attendees to implement a tiny version of Boxer: dl.acm.org/doi/pdf/10.1...
It is a fun example of how interactive programming *systems* can do more than *languages*!
Coming to @programming-conf.bsky.social? Submit a Lightning Talk proposal to share & discuss what you are currently working on!
2025.programming-conference.org/track/progra...
2025.programming-conference.org/track/progra...
May 20, 2025 at 10:08 AM
Coming to @programming-conf.bsky.social? Submit a Lightning Talk proposal to share & discuss what you are currently working on!
2025.programming-conference.org/track/progra...
2025.programming-conference.org/track/progra...
The registration for @programming-conf.bsky.social is still open. Just sayin'...
May 15, 2025 at 7:24 AM
The registration for @programming-conf.bsky.social is still open. Just sayin'...
Last minute arrangements for @programming-conf.bsky.social - visiting the Old Town Hall where the Welcome reception on Monday will be!
May 14, 2025 at 1:26 PM
Last minute arrangements for @programming-conf.bsky.social - visiting the Old Town Hall where the Welcome reception on Monday will be!