Abhinav Sarkar

Ese Large language models are better thinkers than writers. Well okay, they don't think as humans do, but I've been letting it write the vast chunk of my computer programs over the last year or so, which ...

thoughts on ese.
atharvaraykar.com/ese/

It looks great! Though I notice that the RSS feed is gone.

I wrote the fifth part of my #blog series “Implementing Co, a small programming language with #coroutines”. This time, we add support for sleep in #Co for time-based executions. https://abhinavsarkar.net/posts/implementing-co-5/

#Programming #PLT #ProgrammingLanguages #Compilers #Haskell […]

The next session of #Indieweb Club #Bangalore is scheduled on this Saturday 17th January at 2:30 PM IST. Join us this time for a tech and design focused session. We'll co-work on our personal websites, try new designs, squash bugs, or just do some long-neglected digital housekeeping.

If you […]

How I use Jujutsu About three months ago I started using Jujutsu (JJ), a new Version Control System, for my personal projects. It took me a while to get used to it after more than a decade of using Git, but now I’m quite comfortable with it. Working with Jujutsu requires a shift from the mental model of Git. However, it is not as daunting as it may seem on the first day.

I wrote a post about how I use #Jujutsu, the new #VCS: https://abhinavsarkar.net/posts/jj-usage/

#blogging #programming

Notes for the Week #1 (2026) This week note covers the week of 29th December 2025–4th January 2026. Ramp walk This was a week of resting and having fun with family and friends. I was on vacation for most of the week. ## Life We had another well-fed day on the 31st, starting with home-made biryani for lunch, and ordered pizza for dinner. We didn’t do much else, just chilled at home. On 1st January, all of us went to the Namma Bengaluru Aquarium in the Cubbon Park. It was a lot of fun for our 3yo 𝒜. Afterward, we walked around in the park and 𝒜 gathered a lot of cool sticks. What’s with kids liking sticks so much? On the Saturday, we went to The Bangalore Berry Company farm to pick strawberries. The four hour drive (both ways) was a pain, but picking was fun. We also got some fresh vegies. My wife made a strawberry jam today, that I eagerly consumed with pancakes that she also made for breakfast. Alas, the two weeks of fun and frolic are over. I actually stayed in bed most of the day today to recover from all the fun ٭٭happy introvert noises٭٭. ## Health I caught a bad cold early this week, caused by simply forgetting to put on a nightcap. Pleasures of being bald, I guess. Thankfully, I recovered in few days. After being able to walk over 9000 steps consistently every day, I’ve made it my daily goal to walk 10000 steps. This is partially inspired by my friend Sagrika, who did walk 10000 steps everyday in 2025. I hope it helps with reducing the weight I gained this festive season. In other news, I have reading glasses now. Here I thought I’d go one forever with my eyesight sharp, but life had other plans. I just got them last week, and it is taking a while to get adjusted to having a thing in front of my face all the time. ## Personal Work I again spent a lot of time working on the website this week. I promise, I’m done for now. * I changed the dead link checker to run only once a day. This significantly reduced the build time for the rest of 23 builds every day. * I moved the post similarity computations to run as a separate executable, which is run before the site generator is run, and outputs a JSON file with final data. Removing the computation from the site generator reduced the memory usage by a lot, and now I don’t get the alerts every hour. * I added a popular posts and notes section on the homepage. I hope this makes it easier for first-time visitors to find their way around the site. * I added a Microblog Tag Graph page to explore my growing Microblog. It uses a force-directed graph made using d3.js. Let me know what you think about it in comments. ## Recent Posts I wrote a short note collecting all the polls I ran on Mastodon in 2025. I feel like this may become a yearly tradition. ## Watching, Reading, Listening I’m yet to start on a new book this year. However, I watched a lot of TV shows and one movie this week. Wife and I finished rewatching Interior Chinatown. I loved the show again, and I fully recommend it. I continue watching The Ancient Magus’ Bride, though with great sorrow, I decided to stop watching One Punch Man season 3. I’ve never seen such a great manga being turned into such—pardon my language Mr. Spellchecker—a shitshow. I’ve picked some new shows to watch this year, I hope they turn out good. On 31st December, wife and I watched Burn After Reading, a dark comedy spy thriller. Watching Clooney and Pitt really made me feel like going out for a run or a ride. ## Social Media My MastodonWrapped tells me that I spent a lot of time on Mastodon this year. I liked 1800 posts and reposted over 1600 of them! I also posted 870 posts of my own. I gained 140 followers too! ## Interesting Internet Links * 11:59 PM * How should we learn from bugs? * Use Monoids for Construction That’s all for this week. You can subscribe to the feed of my week notes for updates. If you have any questions or comments, please leave a comment below. If you liked this post, please share it. Thanks for reading!

First #weeknote of the year: https://abhinavsarkar.net/notes/2026-weeknotes-01-04/ about new year celebrations, graphs, and terrible TV shows.

#weeknotes #blogging

I like whatever is wrong with my algorithm over there

Notes for the Week #49 This week note covers the week of 24th November–7th December . True Blue * This is my tenth consecutive week of writing week notes! I’m happy that I’m able to keep up this habit. * Winter is here and I’m loving it! Bengaluru generally does not get much cold in winters but this year seem like an exception. I’ve been wearing sweatshirts and jackets every day, sometimes even to sleep. I’m planning to do some winter wear shopping soon. We got our 3yo 𝒜 some cute sweaters. * As my health improves, I’m starting to adopt a move active lifestyle. For now, I’m walking 2–3 kms every day, and I plan to start doing Yoga from January. * Last week I switched from dairy milk to Oat milk after discovering that I’m now allergic to dairy. I’m starting to like the taste after trying it for a week. * Last week I spent most of my free time solving the Advent of Code 2025 puzzles. This year I decided to solve them in Janet, a new-age Lisp that I’ve been wanting to learn. Janet is a Clojure like Lisp that can be interpreted, embedded and compiled, and comes with a large standard library with concurrency, HTTP and PEG parser support. I want to replace Python with Janet as my scripting language. I’m far from good at it, but it feels nice to learn something new. You can browse my solutions on Github. I also wrote a note about my solutions. * Yesterday we had an IndieWebClub Bangalore meeting where we discussed website and post footers, how to design them and what to put in them. We also talked about styles of personal blogging. Folks showcased their favourite websites, and gave suggestions and tips about different ways of writing blogposts. It was really informative for me, and I’m definitely going to take some ideas and implement them in this website. * Today we went to Babai Tiffins, a new-to-us restaurant in our neighbourhood. I’ve been hearing good things about it for a while now. The food was delicious, though not exceptional. Afterward, we got 𝒜 some icecream 🙂, and I finished writing this note. * Some interesting links for this week: * Wenyan-lang * How to write things people actually want to read * Start to finish on self-publishing a technical book That’s all for this week. You can subscribe to the feed of my week notes for updates. If you have any questions or comments, please leave a comment below. If you liked this post, please share it. Thanks for reading!

A new #weeknote! Winter shopping, oat milk and advent of code this time: https://abhinavsarkar.net/notes/2025-weeknotes-12-07/

#blogging

Notes for the Week #47 This week note covers the week of 17th–23rd October. Halfpipe * Starting with health, this week was again fraught with infections. They say toddlers are walking Petri dishes, and it’s not far from truth. My wife and I had a minor viral infection this week but thankfully the toddler was fine. Still, I didn’t feel at 100% and could not get a lot done. * I finished reading _This is How You Lose the Time War_! This is the first fiction book that I’ve read since 2021. Early parenthood is difficult, and sadly, reading fiction was the first thing I gave up. I tried, but it just didn’t hold my (scattered) attention. Thankfully, it’s coming back to me. The book itself was a fascinating read. I’m not much into romances but this one was very different. I’m yet to take the full feeling in, and I will certainly go back and reread parts of it. I wholly recommend it if you are into reading sci-fi and/or romance. * This week, I finally had time and motivation to work on a side project that I’ve been trying to do for months. I wanted a service that takes an RSS feed, and sends me 10 (or 3) items from it every day using a space repetition algorithm as another feed. That way, I can provide it a feed of my favourite articles that I want to keep coming back to, and get to read them again and again over years. After mulling over this for six months and doing two overly complex prototypes, I finally came up with something that works well enough and fits under 500 lines of code. Six months to think, one day to write! I had to let go of using a spaced repetition algorithm because that requires statefulness, and I wanted a stateless minimal solution. So instead the program selects entries randomly with exponential weights calculated from age of entries using the A-Res algorithm. This biases selection toward older entries, making them more likely to be repeated. The repeated entries have their timestamp updated, and become less likely to be repeated again in the near future. I call this program _feed-repeat_ and it is running on my VPS now, echoing my Linkblog and Blogroll feeds. * Some interesting links for this week: * Towards interplanetary QUIC traffic * Why Lexing and Parsing Should Be Separate * Why you speak more Latin than you think That’s all for this week. You can subscribe to the feed of my week notes for updates. If you have any questions or comments, please leave a comment below. If you liked this post, please share it. Thanks for reading!

The new #weeknote is out with news about health, books read and projects done: https://abhinavsarkar.net/notes/2025-weeknotes-11-23/

#blogging

still kind of wild that unwrap is a thing in rust.

like, rust people will be so smug about how their language doesn't have null pointers and then add a function that replicates nullpointerexceptions right in their standard library?

I can't get over the fact that #Rust invented `Option` to avoid NULL pointers, and then added `unwrap` to it, undoing the whole thing.

silhouette of a couple against the evening sky, standing in an open field watching the sunset.

An earnest #sunset #photography

photo of a mechanical keyboard with white, black, light and dark green keycaps.

Gave my aging #MechanicalKeyboard a makeover by changing keycaps. The mix of colors looks pretty cool.

Change of Mind _I wrote this post for a prompt given during ourlocal Indieweb club meeting: “What did you recently change your mind about?”_ I’ve always wanted to write a book, some book, since I can remember, for reasons I’ll not go into in this post. Initially, I had no clue what I wanted to write about. Over years (decades really), I slowly zeroed it down to writing a book about compilers in Haskell. I got interested in Functional Programming while I was a wee J2EE developer back in the aughts. The first language that caught my fascination was Clojure, the excellent Lisp on JVM. But soon enough, the dark side of static typing seduced me and I fell in love with Haskell. Over a decade or so, I’ve read and written enough Haskell code that I can call myself proficient in it. Haskell is now the first language that I reach out to, no matter the size of my project, which I believe is something very uncommon. Along with Haskell and functional programming, usually comes the allurement of compilers and creating your own programming languages. And sure enough the bug bit me hard when the world stopped in 2020. I spent countless hours learning all things compilers from scratch, and writing many of them in Haskell. An idea crossed my mind one day, why not write a book on compilers using Haskell? I spent some time digging up. Turns out, there is only one compiler book that uses Haskell as its implementation language. This is a very bizarre and curious fact, because one of the biggest strengths of Haskell is writing compilers, and there are tens if not hundred of them written already. But only one person wrote a book about the process! I decided to snatch this opportunity. Thereafter, I spent a lot of time thinking about the book, more than a year actually. I wrote the table of contents, I thought about how I’d structure the code examples, even about the publishing software. I also read multiple articles about the process of book-writing by people who have successfully published. After a lot of deliberation and talking to friends, I’ve changed my mind about writing _the_ book. The effort to result ratio just does not seem worth it. This is more true for the kind of writing I do / want to do—an in-depth everything-explained all-code-provided book. I know that I would not be satisfied with anything less. I suspect that if I go down this path, it would take a good chunk of my forties, and I’ll not have enough to show for all the time I put in it. Of course, I could be wrong, but this is what I feel right now. So, I’m changing my mind and I’m giving up. So long, my childhood dream of becoming a famous published author. But it’s not all sad and gloom. I’ll probably do something more useful and fun with my time. I really think that I’ll not regret this decision. But if I do, I suppose I can change my mind about it again! If you have any questions or comments, please leave a comment below. If you liked this post, please share it. Thanks for reading!

I wrote a new #note at my local #Indieweb club: https://abhinavsarkar.net/notes/2025-change-of-mind/

#blogging #personal

I Want You to Understand Chicago Politics Chicago 2025-11-08 I want you to understand what it is like to live in Chicago during this time. Every day my phone buzzes. It is a neighborhood group: four people were kidnapped at the corner drugstore. A friend a mile away sends a Slack message: she was at the scene when masked men assaulted and abducted two people on the street. A plumber working on my pipes is distraught, and I find out that two of his employees were kidnapped that morning. A week later it happens again. An email arrives. Agents with guns have chased a teacher into the school where she works. They did not have a warrant. They dragged her away, ignoring her and her colleagues’ pleas to show proof of her documentation. That evening I stand a few feet from the parents of Rayito de Sol and listen to them describe, with anguish, how good Ms. Diana was to their children. What it is like to have strangers with guns traumatize your kids. For a teacher to hide a three-year-old child for fear they might be killed. How their relatives will no longer leave the house. I hear the pain and fury in their voices, and I wonder who will be next. Understand what it is to pray in Chicago. On September 19th, Reverend David Black, lead pastor at First Presbyterian Church of Chicago, was praying outside the ICE detention center in Broadview when a DHS agent shot him in the head with pepper balls. Pepper balls are never supposed to be fired at the head because they can seriously injure, or even kill. “We could hear them laughing as they were shooting us from the roof,” Black recalled. He is not the only member of the clergy ICE has assaulted. Methodist pastor Hannah Kardon was violently arrested on October 17th, and Baptist pastor Michael Woolf was shot with pepper balls on November 1st. Understand what it is to sleep in Chicago. On the night of September 30th, federal agents rappelled from a Black Hawk helicopter to execute a raid on an apartment building on the South Sho…

Kyle Kingsbury is not a journalist. He is not an op-ed writer.

He is a computer safety researcher.

And he has written one of the most compelling, comprehensive accounts of the ongoing hell in Chicago that you could possibly imagine.

In under 1600 words.

aphyr.com/posts/397-i-...

I did a short survey of #compiler backends: https://abhinavsarkar.net/notes/2025-compiler-backend-survey/

#compilers #programming #pldev #langdev #blogging

Batman "This is the weapon of the enemy" meme format: Batman breaking/shattering "GRADUAL TYPING" while saying "*THIS* IS THE WEAPON OF THE *ENEMY*. WE DO NOT *NEED* IT. WE WILL NOT *USE* IT."

I wrote a new #weeknote: https://abhinavsarkar.net/notes/2025-weeknotes-10-26/

#blogging #weeknotes

I've written a series of blog posts, in which I write a #bytecode #compiler and a #virtualMachine for arithmetic in #Haskell. We explore the following topics in the series:

- Parsing arithmetic expressions to ASTs.
- Compiling ASTs to bytecode.
- Interpreting ASTs.
- Efficiently executing […]

Exploring Arrows for sequencing effects Monads are <em>one</em> way to sequence effects, but they're not the only way!

Don't get too hung up on #Monads, there are other ways to sequence effects; including Arrows; and they provide even better static analysis!

Let me know what you think :)

#Haskell

chrispenner.ca/posts/arrow-...

I wrote a new #note: https://abhinavsarkar.net/notes/2025-self-advice/

#blogging

IndieWebClub Bangalore Website of the IndieWebClub Bangalore community

The website of #IndieWeb Club #Bangalore is finally up at https://blr.indiewebclub.org

I wrote a new #weeknote: https://abhinavsarkar.net/notes/2025-weeknotes-10-19/

#blogging

A screenshot of Miniflux feed reader showing articles sorted by similarity.

Wrote some JavaScript code to customize #Miniflux #feedReader to automatically sort articles by similarity. Now I can read similar articles one after another easily.

I wrote a #note about adding similarity based sorting in #Miniflux #feedReader: https://abhinavsarkar.net/notes/2025-miniflux-similar-sorting/

#blog #programming

Monads are too powerful: The Expressiveness Spectrum Monads are a useful tool, but what costs do we pay for their expressive power?

New blog post!

#Haskell is built on a foundation of Monads, but are they really the optimal way to sequence effects or should we keep looking for something better?

What's the big deal with Applicatives and Selective Applicatives?

Read on!

chrispenner.ca/posts/expres...

I wrote up a retrospective explaining why I ended my Nix Steering Committee term one year early

www.haskellforall.com/2025/09/stee...

YouTube video by Jonathan Aldrich PLP 3.6-3.7: Referencing Environments, Closures, and Macros

How do first-class functions look up the value of a variable from an outer scope? Learn about referencing environments, closures, and macros in my latest Programming Language Pragmatics video!

PLP 3.6-3.7: Referencing Environments, Closures, and Macros - youtu.be/JBs4dY9nwOY

If you write a raytracer in Haskell, the camera must always point in the positive Y direction.

This is because Haskell doesn't allow downcasting.

My Quarterly System Health Check-in It is essential to periodically take a few steps back from the day to day and reflect on where we are against our strategic goals. If you’re an engineering leader, a head of engineering, a director, or a VP, you likely have a recurring meeting to this effect. In this post, I propose a structure for this operational exercise (complementing a business review) that lasts 2-4 hours, every month or quarter. I see quality as solving for the Pareto front with the tangible dimensions of reliability, performance, cost, delivery and security, and the more intangible dimensions of simplicity and social structures. For each dimension, go through the list of questions below and try to answer them together.

I've been poking Srihari, our most experienced engineer @nilenso.com to share his hard-earned knowledge for the benefit of others.

Even if you're not an engineering leader like me, this checklist gives a lot of insight into what makes a great engineering org.

blog.nilenso.com/blog/2025/09...