Over the past two months, I released three new updates of expltools, the bundle that provides the explcheck static analyzer for the expl3 programming language.

These updates include major improvements but did not yet advance the final stage of the pipeline, flow analysis, which I teased in the previous post. That’s because our work on flow analysis so far has been groundwork: figuring out how to adapt static-analysis techniques to expl3 before moving on to implementation.

In this post, I outline the flow graph structure currently used to represent expl3 code and describe our adaptation of the reaching definitions algorithm for dynamically scoped languages like expl3.

Today, I’m excited to release the next major update to expltools, a bundle that includes the static analysis tool explcheck for the expl3 programming language. This update improves upon the semantic analysis processing step introduced in the previous post and lays groundwork for the final processing step of flow analysis.

Today, I’m excited to release the next major update to expltools, a bundle that includes the static analysis tool explcheck for the expl3 programming language. This update finishes the semantic analysis, completing four out of five planned processing steps.

Yesterday I returned from TUG 2025 in Trivandrum, Kerala (July 18–20, 2025), where I was thrilled to present my talk announcing the development of expltools to the broader TeX community.

In this post, I will try to briefly summarize my experience in the form of a travel diary while it is still fresh in my mind. I’ll concentrate on my own experiences rather than the full program details. If you’d like to explore the agenda itself, please consult the conference program and watch the YouTube recordings here: day one, part one and part two, day two, and day three.

I recently reviewed The Legend of Zelda: Breath of the Wild (BotW, 2017) and shared my thoughts after 10 hours with Tears of the Kingdom (TotK, 2023). After logging another 10 hours, I’m ready to revisit the topic. This time, I’ll expand on the emulation experience, share updated impressions, and explain why I don’t plan to finish the game anytime soon.

Today, I’m excited to announce another update to expltools, the bundle that includes the static analysis tool explcheck for the expl3 programming language. This release significantly extends support for the semantic analysis processing step.

In this post, I’ll explain what this means for expl3 programmers, what functionality is still missing, and provide a realistic estimate for when full support for semantic (and flow) analysis can be expected. I’ll also discuss how this impacts the project roadmap.

Additionally, I’d like to tease a work-in-progress article titled Expltools: Development tools for expl3 programmers, forthcoming in TUGboat 46(2) or (3), along with my upcoming talk this July at TUG 2025 in India.

Finally, as a follow-up to the previous two posts, in which I described how I collaborated with package authors to fix issues detected by explcheck, I’ll provide updates on the status of those tickets.

I recently reviewed The Legend of Zelda: Breath of the Wild (BotW, 2017). In this article, I’ll share my early thoughts after about 10 hours spent with its sequel, The Legend of Zelda: Tears of the Kingdom (TotK, 2023).

In this article, I will share my thoughts after spending around 100 hours playing The Legend of Zelda: Breath of the Wild (BotW, 2017) for the first time.

Today, I’m excited to announce another update to expltools, the bundle that includes the static analysis tool explcheck for the expl3 programming language. This update introduces initial support for semantic analysis. In this post, I’ll explain what this means for expl3 programmers, what’s still missing, and where we’re headed next.

In a previous post, I introduced a public website listing issues in current TeX Live packages detected by explcheck. This time, I’ll also talk about how I’ve been using that resource to collaborate with package authors and help fix real-world issues.

Three weeks ago, I released my classic browser-based snake game — a project I started 15 years ago — under a free and open-source license.

In my previous three posts, I introduced the various systems, their interactions, the game design, and the underlying technologies. In this post, I will close off this series by outlining some future work.

Three weeks ago, I released my classic browser-based snake game — a project I started 15 years ago — under a free and open-source license.

In my previous two posts, I introduced the various systems that power the game and how they interact. Today, I’ll dive into the game’s design, its influences, and the underlying technologies.

Three weeks ago, I released my classic browser-based snake game — a project I started 15 years ago — under a free and open-source license.

In my previous post, I introduced the various systems that bring the game to life. In this post, I’ll explore how these systems interact to create a balanced and engaging gameplay experience.

Today, I’m excited to release the next major update to expltools, a bundle that includes the static analysis tool explcheck for the expl3 programming language. This update introduces syntactic analysis, completing three out of five planned processing steps.

Two weeks ago, I released my classic browser-based snake game — a project I started 15 years ago — under a free and open-source license.

In this post, I’ll walk you through the game’s fundamental loop and explain the various systems that bring it to life.

In the late 2000s, I was an active member of the Czech bulletin board https://diskuse.jakpsatweb.cz, a vibrant space where hobbyists, academics, and professionals shared ideas about web development.

On July 29, 2010, I introduced an early version of a web browser game called DHTML Snake in a forum post. In that post, I explained the game’s systems, implementation details, and invited feedback. Over the next couple of years, I incrementally improved the game by following my own creative direction and incorporating suggestions from high school classmates.

After more than a decade without updates, I revisited the project yesterday. I cleaned up the code and released it under a free, open-source license on GitHub.

You can try the game here using your computer’s keyboard and mouse. 🤞

Since last December, I’ve released five updates to expltools, a bundle that includes the static analysis tool explcheck for the expl3 programming language.

In v0.4.0 (January), I introduced the second processing step: lexical analysis. As noted in my previous blog post, this step converts the expl3 parts identified during preprocessing into TeX tokens, opening the door to deeper program analysis.

Throughout the rest of January, I focused on improving the lexical analysis and enhancing user experience. Notably, in v0.5.0, I added support for ignoring issues with inline TeX comments % noqa and the command-line option --ignored-issues. Furthermore, in v0.6.0 and v0.6.1, I implemented TOML config files to allow users to configure explcheck for their projects.

In v0.7.0 and v0.7.1 (February), I continued refining issue detection. To assist with validation, I added regression tests that regularly scan all expl3 files from TeX Live versions 2013 to 2023, comparing results to baselines as part of our continuous integration process.

Furthermore, in collaboration with Oliver Kopp and with the advice of Norbert Preining, we launched a public website that lists all issues in current TeX Live detected by explcheck.

Two weeks ago, I announced the first public release of expltools, a bundle that includes explcheck, a static analysis tool for the expl3 programming language.

Since then, the project has sparked a lively discussion in the project repository, engaging early adopters, contributors, and enthusiasts. This feedback loop has already resulted in two new releases within the past two weeks, and another update is planned for next Monday (December 23).

On December 14, I also had the opportunity to present explcheck during a talk at the general assembly of the Czechoslovak TeX Users Group (CSTUG). Although the talk was delivered in Czech, the presentation slides are in English and should provide a clear overview of the topics discussed.

This week has been an exciting one for the TeX and LaTeX community in Brno, with Frank Mittelbach, a key figure from the LaTeX team, visiting Masaryk University to deliver talks on the history and the future of LaTeX.

Alongside his visit, I introduced explcheck, a static analysis tool for the expl3 programming language, with its first public release now available on CTAN.

As part of my seminar talk, I demonstrated explcheck’s capabilities, including a deep dive into 11 years of expl3 usage statistics, which reveal intriguing trends about its adoption and integration into the TeX ecosystem.

In September, I wrote a project proposal for developing a static analysis tool (so-called linter) for the expl3 programming language. I submitted the proposal to the TeX Development Fund and I’m thrilled to share that the proposal has been accepted. The project was awarded a grant of US$2000, spread over the next 12 months. At the end of this period, I’ll be presenting a final report as a TUGboat article, potentially as early as at TUG 2025 in तिरुवनन्तपुरम्.

This is my fourth devlog post for the development of a static analysis tool (so-called linter) for the expl3 programming language, which would help developers to discover bugs in their expl3 programs before even running them.

This is my third devlog post for the development of a static analysis tool (so-called linter) for the expl3 programming language, which would help developers to discover bugs in their expl3 programs before even running them.

Between family holiday, my wife’s trip to Кыргызстан, freelance work, and TUG 2024, I have had precious little time for the project since my previous post.

This is my second devlog post for the development of a static analysis tool (so-called linter) for the expl3 programming language, which would help developers to discover bugs in their expl3 programs before even running them.

In 2021, I used the expl3 programming language for the first time in my life. I had already been eyeing expl3 for some time and, when it came to defining a LaTeX-specific interface for processing YAML metadata in version 2.11.0 of the Markdown package for TeX, I took the plunge.

I recently acquired a DELL Inspiron 15 7559 notebook and decided to supplement the pre-installed Windows OS with Debian Linux (Stretch), which has been my daily driver OS for about two years now and will soon become the stable Debian version. The machine contains two GPUs — an integrated Intel 915G GPU, and a dedicated nVidia GTX960M GPU — that are interconnected via the the nVidia Optimus GPU switching technology.

I did a remix of the Persona 3 “Mass Destruction” theme from the “Burn My Dread -Reincarnation: Persona 3-” album by Shoji Meguro (Atlus) and two versions of “Megalovania” from Undertale and Homestuck by Toby Fox.

The drawings of Sans and Gaster Blaster were kindly provided by Sallintha. The animation was created using Synfig Studio – a free open-source animation software that provides command-line rendering. All the assets and project files are available in a Git repository along with the two other remixes of the songs I did earlier.

I have discovered a nice algorithm for bitmap generation on GitHub today along with its C# implementation. It has the nice property of being easily understood but producing intriguing results.

After a bit of an ado, my submission to the Czechoslovak TeX Users Group Bulletin has been published.

During the course of this year, I have been working on witiko/markdown as a part of a project funded by the Masaryk University in Brno, Czech Republic. The project is based on the jgm/lunamark codebase and as of today, all the bugfixes (17) and syntax extensions (19, 20) introduced in witiko/markdown were merged into jgm/lunamark. This effectively concludes the project.

While I was watching the first volume of JoJo’s Bizzare Adventure: Diamond is Unbreakable, I fell in love with the battle theme of Koichi Hirose (Yuuki) and wondered what a remix with the intro theme of JoJo’s Bizzare Adventure: Phantom Blood (Sono Chi no Sadame) would sound like. Since the JoJo’s Bizzare Adventure: Diamond is Unbreakable OST got released on July 27th, I decided to throw together a quick prototype.

Lately, I have been stitching some of the panoramas I took during the vacation using Hugin. Since I took quite a lot of these, I though I would leverage the shell and let Hugin create the panoramas automatically using the workflow described at http://wiki.panotools.org/Panorama_scripting_in_a_nutshell.

This is our second day in the Yellowstone national park. Our plan for today is to cover the northwestern part of the part. Our first stop are the Artists’ Paintpots located between the Madison and Norris areas.

We will be spending the next four days in the Yellowstone national park. Today, we are headed to the West Thumb and Old Faithful areas. Our morning was spent in the Grand Teton national park.

Today, we are headed to the Grand Teton National Park.

Today, we are travelling across the state of Wyoming.

Today, we are headed to the Rocky Mountains National Park.

Today, we are headed to the Black Canyon of the Gunnison National Park.

Today, we are headed to the Mesa Verde National Park, where the dwellings of the Ancestral Pueblo people, who called Mesa Verde their home during 500s–1300s A.D., can be found. Perhaps most fascinating are the cliff dwellings built in the alcoves in the surrounding canyon sides, where the Ancestral Pueblo people retreated from the mesa tops during the 1200s. Shortly after that the people disappeared – presumably due to a long period of droughts, as evidenced by the annuli of the well-preserved pine logs that were used to support the building roofs, or an internal struggle.

Today, we are headed to the Monument Valley – a national park at the northern rim of Arizona where monumental rock formations, mesas and buttes predominate over the desolate wasteland.

Today, we are headed to the Grand Canyon National Park on a hike along the southern rim.

Today, we are headed to the Antelope Canyons in the Navajo Tribal Park. The entrance fees are pretty steep ($46 + $8 tribal fee per a visitor) and the ride on the back of an all-terain vehicle to the entrance to the upper canyon is fairly uncomfortable with all the sand flying around. The sights, however, are well worth the trouble.

Today, we are headed to the Bryce Canyon National Park.

Today, we are headed to the Zion National Park.

Today, we are moving from California to Utah across the southern rim of Nevada and the northern rim of Arizona and we are visiting the Valley of Fire state park along the way.

After a day of rest in the LA, we are now heading to the east. First stop: the Joshua Tree National Park.

Today we are taking some much-needed rest after the long flight before heading to Arizona. And what a better place to rest than the Hollywood Boulevard.

Having left Velešín in the early morning, we made it through the immigration interview at the Prague airport and departured at noon (GMT+2). Arrived in at the New York airport at 16:00 (GMT-4) and then at the Los Angeles airport at 21:30 (GMT-7).