This year was my first time attending the ACM SIGPLAN International Conference on Functional Programming in Berlin, Germany. It was an amazing opportunity to learn about a lot of cutting-edge research in programming languages, but I also capitalized on my time and made a lot of new friends and acquaintances along the way.

Racketfest

Prior to the main ICFP conference was a smallish conference known as Racketfest — a celebration of all things Racket. We had a keynote and four talks this year:

“Language-Oriented Programming the Racket Way” — Matthew Flatt (Keynote). Matthew explained the Racket philosophy: instead of struggling to find out how to solve your problem in an existing language, simply build the right language for the job.

“Privacy-Hardened Languages in Racket” — Kristopher Micinski. Kris explained the principles of faceted execution (a technique for segregating data’s properties based on the current user) and how he integrated these ideas into a new #lang for Racket called Racets.

“Small, Elegant, Practical: The Benefits of a Minimal Approach” — Prabhakar Ragde. Prabhakar is a lecturing faculty at Waterloo University who spends a lot of time focusing on how to improve his introductory courses. Waterloo is notable for being one of the few schools where Racket is used as students’ first language. This talk emphasized the utility of a small core language for education.

“A Normalizing #lang” — David Thrane Christiansen. David works at Galois, a Portland-based company usually noted for primarily using Haskell. For this talk, David explained how to convert an evaluator to a normalizer — a useful technique for certain theoretical applications (such as implementing a proof assistant).

“The Heresy Programming Language, or: Learning through Madness” — Annaia Berry. Annaia walked through her process implementing the Heresy #lang: a BASIC dialect with a very Lispy flavor. She talked a lot about the process of implementing language features “the wrong way” and how sometimes doing things the wrong way is the best way to learn how to do it the right way.

After the talks, we went to lunch at a local market and got to know each other over good food. Then we returned to the venue and enjoyed an informal “office hours” where attendees could talk to the presenters and ask for their input on various ideas. Overall, Racketfest was hugely fun and I’m glad I was able to go.

PLMW

The Sunday before ICFP, there are a number of workshops that people can attend. This year, I chose to go to the Programming Languages Mentoring Workshop (PLMW), a workshop intended primarily for PhD students and soon-to-be PhD students. Most attendees of PLMW are there on a scholarship offered by the conference, which I think is very cool (although I was not one of them).

The first couple of talks were essentially digests of research presentations. We had Sam Lindley from the University of Edinburgh and Imperial College London talk about his work in effect handlers, and then we learned about refinement types and Liquid Haskell from Niki Vazou of IMDEA (a research institute based in Spain). (Of course since I love all things types, I liked the latter quite a lot!)

The remainder of the talks were less technical:

  • Amal Ahmed (Northeastern University) talked about how to manage your time well during the early phases of your PhD, as well as how to find an advisor who works well with you.
  • Kathleen Fisher (Tufts University) gave information about how to manage a good work-life balance during your PhD and throughout an academic career.
  • Ilya Sergey (Yale-NUS College) talked about the far-reaching implications of “functional** programming in industry and in academia.
  • Derek Dreyer (Max Planck Institute and ICFP 2019 General Chair) gave a talk about how to give a talk that people can follow, which had a lot of good points that I might write up some time.

Following the talks (which included lunch and breaks), we had an opportunity to get to know each other better through a competition! We were split into teams of five and given a set of 20 algorithms implemented in different (and often uncommon) languages, which we had to identify from a list of options and race to submit the correct answers. At the end of the competition, there was a tie for first and a tie for third, so a tiebreaker was held. My team ended up winning our tiebreaker (no thanks to me) and we finished third! As reward, we all got IMDEA-branded stainless steel water bottles.

The last PLMW event was a panel moderated by Simon Peyton Jones. Panel members included Satnam Singh (who had been in academia but moved to industry with Google), Zoe Paraskevopoulou (a PhD student at Princeton), Jeremy Gibbons (Oxford and editor-in-chief of the Journal of Functional Programming), Andrey Mokhov (Newcastle University), and Amal Ahmed (Northeastern). In addition, many other veterans of the field chipped in with their responses to questions. In retrospect, I probably should’ve taken notes on all the good questions!

Morning Keynotes

Each day of the main conference (Monday–Wednesday** started with a keynote. I believe these will be uploaded at some point. The talks were:

  • Monday: “Blockchains are Functional” — Manuel Chakravarty (Tweag I/O)
  • Tuesday: “Solver-Aided Programming for All” — Emina Torlak (University of Washington)
  • Wednesday: “Derivations as computations” — Andrej Bauer (University of Ljubljana)

I most enjoyed the second keynote. Emina talked a lot about the Rosette #lang, which is often considered an exemplar of Racket’s capabilities.

Technical Talks

Of course the main meat of ICFP is the technical talks! These were all recorded and will be made available at some point, but a few in particular stood out to me. I’ll just give some brief highlights here from the main conference:

Rebuilding Racket on Chez Scheme (Experience Report). The Racket team has been working for a while on moving their code base from mostly C to Chez Scheme. Although performance has suffered slightly in most cases (some 3% increase in execution time), the team considers the endeavor to have been mostly useful due to significant improvements in maintainability.

Approximate Normalization for Gradual Dependent Types. While I didn’t pay much attention to the normalization aspect of this talk, I really loved their effort in building gradual dependent types. Dependent types are useful but a bit much to be used everywhere in regular programming, so providing the ability to only use them sometimes (i.e., gradually) is a huge boon to the user experience. The PI for this work was Ronald Garcia at UBC, who is on my shortlist for potential advisors (which I’ll talk more about in a blog post soon, I think).

Selective Applicative Functors. Haskell has support for varying levels of abstraction leading up to monads (functors, applicatives, monads), and this team believes they’ve identified a deficiency in this hierarchy. To solve this, they introduced the selective, which sits between applicatives and monads.

Teaching the Art of Functional Programming Using Automated Grading (Experience Report). McGill University has been testing an online student homework suite called Learn-OCaml. This software is intended as an automated grader which can also offer feedback and suggestions to students so they can improve without needing to wait until after grading. This paper was an evaluation of the first year or so of using this software in introductory courses at McGill.

The future of OCaml PPX: towards a unified and more robust ecosystem (OCaml Workshop). While I don’t use OCaml as an everyday language, I thoroughly enjoyed listening to the ideas going around for improving its metaprogramming facilities.

Functors and Music (Demo at FARM). This was an extremely impressive demo that showed off a Haskell DSL for making music. The author showed how to write a new song live. It was really a very impressive demo! I really liked this one.

Of course, a large motivation in attending ICFP this year was to meet faculty who I might like to work under for my PhD. I had a list of people I wanted to talk with prepared before I arrived, but I also capitalized on any opportunity to meet people I hadn’t expected to. In general, everybody I spoke to was incredibly supportive and willing to chat about my interests and whether they felt they might be a good match for me (and often who else I should talk to who might fit better!).

While I talked to many faculty during my time at ICFP, there are some people who I had more specific conversations with about my intended focus of research and/or the PhD application process. Many thanks to the following people for helping me in this regard:

  • Dan Friedman (Indiana University)
  • Ryan Newton (Indiana University)
  • Chung-chieh Shan (Indiana University)
  • Sam Tobin-Hochstadt (Indiana University)
  • Kris Micinski (Syracuse University)
  • Amal Ahmed (Northeastern University)
  • Kathleen Fisher (Tufts University)
  • Norman Ramsey (Tufts University)
  • William Bowman (University of British Columbia)
  • Ronald Garcia (University of British Columbia)
  • Cyrus Omar (University of Michigan)
  • Matthew Flatt (University of Utah) (he couldn’t escape me even here!)
  • David Darais (University of Vermont)

(Names are grouped by university in alphabetical order.)

Other Fun

I attended a lot of technical talks, but I also wanted to make the most of my short time in Berlin! I was fortunate to make some good friends throughout the conference, and together we managed to have a really good time. We ate good food, saw some history (such as the Berlin Wall Memorial, among others), and otherwise enjoyed one another’s company. Special thanks especially to my new Twitter and conference BFF Paulette Koronkevich (@koronkebitch) who introduced me to many other people and was generally great to explore with.

On Monday night, we organized a group to go to a local comedy show where one of the conference attendees (Joachim Breitner / @nomeata) was performing. We had a great time and loved the comedy — plus we went to get some very good burgers afterwards!

On Wednesday, I went with my new friends Madelyne (@madxiaodisease) and Clark (@CRY3rn) to check out a tour of some Cold War bunkers. We missed the tour by a few minutes, but we still managed to have a good time seeing some of the sights. We saw the Berlin Wall Memorial, the Reichstag, Brandenburg Gate, and the Memorial to the Murdered Jews of Europe. Berlin is rich with history, and I’m glad we were able to make some time to see at least a part of it!

Thursday morning, Paulette and I decided we wanted chocolate (because who doesn’t want chocolate), so we went to Rausch Schokoladenhaus and WOW was it worth the visit. On the third floor, there’s a cafe that specializes in various chocolate-based desserts. We had a great time trying the creme brulee, a raspberry torte, an eisschokolade (“ice chocolate”), and other small pieces here and there. I picked up a few things to take home, which I’m looking forward to enjoying with my friends there!

Then, on Thursday night, there was an industry reception with speakers from Galois, Jane Street, Google, Facebook, and ahrefs. I ended up having a great conversation with Yaron Minsky, Jane Street’s CTO, with a group of other students for a couple hours, which I really enjoyed. He had a lot to say about OCaml, functional programming in industry, and lots of other things along the way.

Friday afternoon, I had the good fortune to end up at a lunch table with Yaron Minsky (Jane Street’s CTO), Kathleen Fisher (professor at Tufts University), and Simon Peyton Jones (a heavyweight in PL research for a few decades now, who works at Microsoft Research at Cambridge). We talked about a lot of things, but especially interesting was our discussion regarding the representation of women in STEM (and CS specifically) both in industry and in academia. I really appreciate that they were so willing to let me join in the discussion with them despite none of them knowing me (except Yaron, who I’d only met the night before).

Parting Thoughts

Overall, I am so happy that I attended this conference. I really had a great time meeting everyone and learning so much about what’s happening in this field. More than anything, this has solidified my resolve to go after my PhD and work on things like this.

I would like to specifically give thanks to my (now former) PI, Michael Adams, who was kind enough to fund this journey. I often say I wouldn’t be where I am now without his help and support over the past few years, but his willingness to send me to Germany to learn from all these other great people will forever stand apart. Thanks for everything, Michael!

Also, thanks to my new PI, Eric Eide, for letting me disappear for a week and a half less than a month after starting with his group. I really appreciate it!

Lastly, you may have noticed, but there are a few Twitter handles in the above text. It turns out that programming languages people are very active on Twitter! It’s a great way to organize and stay in touch. (If you read this and want to be friends, feel free to follow me @_pdarragh!)

Overall, ICFP 2019 was really great. Thanks to everybody who contributed to making it such an amazing and memorable experience. I can’t wait to see you all next year!