code • words • emotions

Daniel Janus’s blog

Testing a compiler that can’t even print stuff out

25 September 2021

I’m enjoying a week-long vacation. In addition to other vacationy things (a trip to Prague, yay!), I wanted to do some off-work programming Just For Fun™ and revisit one of my dormant pet projects, to see if I can make some progress.

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Things I wish Git had: Commit groups

1 July 2021


Everyone 1 and their dog 2 loves Git. I know I do. It works, it’s efficient, it has a brilliant data model, and it sports every feature under the sun. In 13 years of using it, I’ve never found myself needing a feature it didn’t have. Until recently.

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I made a website to guess tomorrow’s number of COVID-19 cases, and here’s what happened

8 November 2020


It seems so obvious in hindsight. Here in Poland, people have been guessing it ever since the pandemic breakout: in private conversations, in random threads on social media, in comments under governmental information outlets. It seemed a matter of time before someone came up with something like this. In fact, on one Sunday evening in October, I found myself flabbergasted that apparently no one yet has.

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Making of “Clojure as a dependency”

8 May 2020

In my previous post, “Clojure as a dependency”, I’ve presented the results of some toy research on Clojure version numbers seen in the wild. I’m a big believer in reproducible research, so I’m making available a Git repo that contains code you can run yourself to reproduce these results. This post is an experience report from writing that code.

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Clojure as a dependency

2 May 2020

I have a shameful confession to make: I have long neglected an open-source library that I maintain, clj-tagsoup.

This would have been less of an issue, but this is my second-most-starred project on GitHub. Granted, I don’t feel a need for it anymore, but apparently people do. I wish I had spent some time reviewing and merging the incoming PRs.

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Indenting cond forms

10 February 2020

Indentation matters when reading Clojure code. It is the primary visual cue that helps the reader discern the code structure. Most Clojure code seen in the wild conforms to either the community style guide or the proposed simplified rules; the existing editors make it easy to reformat code to match them.

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Careful with that middleware, Eugene

21 January 2020


I’ll be releasing version 0.3 of Skyscraper, my Clojure framework for scraping entire sites, in a few days.

More than three years have passed since its last release. During that time, I’ve made a number of attempts at redesigning it to be more robust, more usable, and faster; the last one, resulting in an almost complete rewrite, is now almost ready for public use as I’m ironing out the rough edges, documenting it, and adding tests.

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Word Champions

3 January 2020

This story begins on August 9, 2017, when a friend messaged me on Facebook: “Hey, I’m going to be on a TV talent show this weekend. They’ll be giving me this kind of problems. Any ideas how to prepare?”

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Web of Documents

7 October 2019

In 1960, Ted Nelson envisioned a web of documents.

It was called Xanadu. It was a grand, holistic vision: of documents that, once published, are available basically forever; of bidirectional links that could glue together not just documents, but parts thereof; of managing copyright and royalties. It was complex. And it never really came to fruition.

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Re-framing text-mode apps

5 February 2019


“But, you know, many explorers liked to go to places that are unusual. And, it’s only for the fun of it.” – Richard P. Feynman

A couple of nights ago, I hacked together a small Clojure program.

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