The 34th Symposium on Implementation and Application of Functional Languages (IFL 2022)

Nyhavn in Copenhagen Frederiksberg Campus Rosenborg Castle
Sponsored by


The goal of IFL is to bring together researchers and developers actively engaged in the implementation and application of functional programming languages and function-oriented programming. IFL 2022 is held in beautiful Copenhagen, Denmark and is a venue for researchers to present and discuss new ideas and concepts, work in progress, and publication-ripe results related to the implementation and application of functional programming languages and function-oriented programming. See the call for papers in text format and the topics of interest.


Submission deadline of draft papers:August 8th, 2022 (EXPIRED)
Notification of acceptance for presentation:August 9th, 2022 (EXPIRED)
Early registration deadline:August 15th, 2022 (EXPIRED)
Late registration deadline:September 1st, 2022 (EXPIRED)
IFL Symposium:August 31st - September 2nd, 2022 (EXPIRED)
Submission of papers for peer-reviewed proceedings:December 5th, 2022
Notification of acceptance:February 2nd, 2023
Camera-ready version:March 14th, 2023


We are pleased to announce the following keynote talks:

Keynote: Abstract machines and functional language implementation

Peter Sestoft, Professor, Head of Department, IT University of Copenhagen. Image of Peter Sestoft

Machines for functional language implementation have a long history, starting with Landin's 1964 SECD machine. We review some historical developments for strict as well as lazy functional languages. For some time it was believed that functional language implementation required specialized hardware, but nowadays virtual machines ostensibly designed for object-oriented languages, notably the Java Virtual Machine and the .NET platform, have turned out to be excellent targets for (strict) functional languages also.

Speaker: Peter Sestoft has worked with functional programming, program manipulation and programming language implementation for nearly four decades and since 2017 is head the Computer Science Department at the IT University of Copenhagen.

Keynote: Verse - a new functional-logic language

Lennart Augustsson, Principal Programmer, Epic Games. Image of Lennart Augustsson

Verse is a new functional-logic language. It has several unusual features and this talk will give a brief overview of the language and what makes it different from most other languages.

Speaker: Lennart Augustsson has been working with design and implementation of functional languages since the 1980s. The languages range from hardware design to banking, but as a grumpy old man he has now settled on the computer games industry.

Keynote: MirageOS: using functional programming to reduce software complexity

Thomas Gazagnaire, Chief Technology Officer and co-founder, Tarides. Image of Thomas Gazagnaire

Today's software stack is overly complex and primarily written in unsafe memory languages. This leads to many inefficiency and security issues. MirageOS tackles these challenges by rewriting an operating system in OCaml, as a set of independent, re-usable libraries. The application business logic can then be linked with these libraries to generate "unikernels": minimal, type-safe and specialised operating systems that do not need a legacy operating system to run anymore.

Speaker: Thomas Gazagnaire is interested in applying functional programming research to solve complex, real-world computer system problems. He has co-founded Unikernel Systems and Tarides and worked for Docker, Citrix, OnApp and OCamlPro. He also was a researcher at Cambridge University and Inria.


The format of the programme is as follows:

Wednesday, August 31st
Location:Thorvaldsensvej 40, Room A2-84-01
09:00-10:00Keynote (Session chair: Fritz Henglein)
10:00-10:30Break (Thorvaldsensvej 40, Marmorhallen)
10:30-12:00Session I (Reversible computing — Session chair: Martin Elsman)
  • Towards Inversion of Tail-recursive Term Rewriting Systems. Maria Bendix Mikkelsen, Robert Glück and Maja Hanne Kirkeby.
  • Jeopardy: An invertible functional programming language. Joachim Kristensen, Robin Kaarsgaard and Michael Kirkedal Thomsen.
  • Announcements
12:00-13:30Lunch (Thorvaldsensvej 40, Marmorhallen)
13:30-15:00Session II (TYPES I — Session chair: Morten Rhiger)
  • Heuristics-based Type Error Diagnosis for Haskell: the case of type families. Niels Kwadijk and Jurriaan Hage.
  • Verified Technology Mapping in an Agda DSL for Circuit Design. João Paulo Pizani Flor and Wouter Swierstra.
  • Verified Causal Broadcast with Liquid Haskell. Patrick Redmond, Gan Shen, Niki Vazou and Lindsey Kuper.
15:00-15:30Break (Thorvaldsensvej 40, Marmorhallen)
15:30-17:00Session III (Compilation — Session chair: Troels Henriksen)
  • The Foil: Capture-Avoiding Substitution With No Sharp Edges. Dougal Maclaurin, Alexey Radul and Adam Paszke.
  • On Generating Out-Of-Core GPU Code for Multi-Dimensional Array Operations. Patrick van Beurden and Sven-Bodo Scholz.
  • Compiling Haskell for Energy Efficiency: Analysis of Individual Transformations. Bernardo Santos, João Fernandes, Maja Kirkeby and Alberto Pardo.
17:00-18:00Welcome reception (Thorvaldsensvej 40, Marmorhallen)
18:00-xx:zzSelf-organized dinners
Thursday, September 1st
Location:Bülowsvej 17, Festauditorium
09:00-10:00Keynote (Session chair: Martin Elsman)
10:00-10:30Break (i front of Festauditorium)
10:30-12:00Session IV (Memory management — Session chair: Fritz Henglein)
  • Compiling a functional array language with non-semantic memory information. Philip Munksgaard, Cosmin Oancea and Troels Henriksen.
  • Strongly-Typed Multi-View Stack-Based Computations. Pieter Koopman and Mart Lubbers.
  • Higher-ranked region inference for polymorphic, lazy languages. Ivo Gabe de Wolff and Jurriaan Hage.
12:00-13:30Lunch (in front of Festauditorium)
13:30-14:30Session V (Editing and IFL Matters — Session chair: Jurriaan Hage)
  • A Structure Editor with Type-Safe Copy/Paste. Hans Hüttel, Christoffer Lind Andersen, Nana Gjerulf Sandberg, Anja Elisasen Lumholtz Nielsen and Peter Mikkelsen.
  • IFL Matters. Presentation and discussion moderated by chairs.
14:45-15:15Transport in groups by bus and metro (30 min.), walking and metro (30 min.) or walking (50 min.) to Ofelia Plads
16:10-17:15Social event: Canal tour of Copenhagen (with refreshments)
Departure: Ofelia Plads, harborside boat landing ("Stromma kanalrundfart"). Arrival: Refshaleøen
17:30-19:30Social event: Dinner at Reffen Street Food
Friday, September 2nd
Location:Bülowsvej 17, Festauditorium
09:00-10:00Session VI (TYPES II — Session chair: Martin Elsman)
  • First-Class Data Types in Shallow Embedded Domain-Specific Languages using Metaprogramming. Mart Lubbers, Pieter Koopman and Rinus Plasmeijer.
  • Set-theoretic Types for Erlang. Albert Schimpf, Stefan Wehr and Annette Bieniusa.
10:00-10:30Break (in front of Festauditorium)
10:30-12:00Session VII (Data transformation — Session chair: Pieter Koopman)
  • How to fold and color a map: Comparing Use-Cases of Tree-Fold vs Fold-Left. Jim Newton.
  • Systems of partial values and their applications in Haskell. Natasha England-Elbro.
  • Ztrategic: Strategic Programming with Zippers. José Nuno Macedo, Emanuel Rodrigues, Marcos Viera and João Saraiva.
12:00-13:30Lunch (at Cafe Væksthus)
13:30-14:30Session VIII (Data and analytics — Session chair: Troels Henriksen)
  • Asynchronous Shared Data Sources. Mart Lubbers, Haye Böhm, Pieter Koopman and Rinus Plasmeijer.
  • An SQL Frontend on top of OCaml for Data Analysis. Yan Dong, Yahui Song and Wei-Ngan Chin.
14:30-15:00Break (in front of Festauditorium)
15:00-16:00Industrial Keynote (Session chair: Fritz Henglein)
16:00-17:00Industrial Reception, good-bye
Notice that the programme is subject to minor changes.

Accepted Papers


All contributions must be written in English. Papers must use the ACM two columns conference format, which can be found here. (For LaTeX users, start your document with \documentclass[format=sigconf]{acmart}.) Note that this format has a rather long but limited list of packages that can be used. Please make sure that your document adheres to this list.

Contributions submitted for the draft paper deadline must be between two and twelve pages long. For the final proceedings twelve pages (excluding references) is the hard upper limit. Especially application papers might be considerably shorter.

Submission link: EasyChair

Post-symposium peer-review

Following IFL tradition, IFL 2022 will use a post-symposium review process to produce the formal proceedings.

Before the symposium authors submit draft papers. These draft papers will be screened by the program chair to make sure that they are within the scope of IFL. The draft papers will be made available to all participants at the symposium. Each draft paper is presented by one of the authors at the symposium. Notice that it is a requirement that draft papers that are accepted for presentation are presented physically at the symposium.

After the symposium every presenter is invited to submit a full paper, incorporating feedback from discussions at the symposium. Work submitted to IFL may not be simultaneously submitted to other venues; submissions must adhere to ACM SIGPLAN's republication policy. The program committee will evaluate these submissions according to their correctness, novelty, originality, relevance, significance, and clarity, and will thereby determine whether the paper is accepted or rejected for the formal proceedings. Papers that are accepted for the formal proceedings are published in the International Conference Proceedings Series of the ACM Digital Library, as in previous years.

Reviewing is single blind. There will be at least 3 reviews per paper. The reviewers have 6 weeks to write their reviews. For the camera-ready version the authors can make minor revisions which are accepted without further reviewing.

Peter Landin prize

The Peter Landin Prize is awarded to the best paper presented at the symposium every year. The honored article is selected by the program committee based on the submissions received for the formal review process. The prize carries a cash award equivalent to 150 Euros.

Topics of interest

Topics of interest to IFL include, but are not limited to:


The symposium will be held physically on the Frederiksberg Campus of the Faculty of Science at the University of Copenhagen. Day 1 (August 31st) will be in meeting room A2-84.01 at Thorvaldsensvej 40. Days 2 and 3 (September 1st and 2nd) will be in the Celebration Auditorium (Festauditorium) at Bülowsvej 17; see the IFL 2022 map.

Copenhagen is easy to get to by plane, train and bus. See IFL 2022 map of Copenhagen. For public transportation within Copenhagen by any combination of train, rapid transit (S-tog), metro and bus, download the app "DOT Tickets", register a credit card, and buy a 2-zone ticket at the start each trip of one hour or less. (For the trip from/to the airport you need a 3-zone ticket.) Alternatively, walk, bike (e.g. via Donkey Republic, Bycyklen, Lime apps) or drive (parking is available at the venue; contact the IFL general chair).

We have not made agreements with specific hotels since Copenhagen is densely packed with hotels at various price levels, all accessible by convenient and frequent public transport from and to the venue. For example WakeUp Copenhagen features small modern rooms, affordable rates and has multiple locations in Copenhagen, including the city center and near Copenhagen Airport. See Google,,, AirBnB, TripAdvisor, Momondo, etc, for accommodation. It is a good idea to check cancelation policies in case of last-minute changes such as COVID-19 measures or flight cancelations.

Denmark presently has no entry or other restrictions due to COVID-19. In particular, there are no limitations on sizes of gatherings; wearing face masks is welcome, but is not required anywhere. Health authorities are continuously monitoring Omicron variant infections. Since these have not led to increased hospitalization (yet), no restrictions have been contemplated (yet). The IFL 2022 organizers are carefully following the COVID-19 situation. In the unlikely event of a COVID-19-based imposition of travel or other restrictions in Denmark, IFL 2022 will be held in hybrid format. In such case, at the time of notification authors of accepted papers will be given the option to present their work remotely.


Registration fee:
Early registration, regular:DKK 1600
Early registration, student:DKK 1200
Late registration, regular:DKK 2000
Late registration, student:DKK 1600
All fees are including 25% Danish VAT. Aproximate conversion rates: DKK 1000 ~ EUR 135 ~ USD 135 ~ GBP 115 ~ 18750 Yen.

The registration fee covers use of facilities, participation, lunches, coffee breaks, receptions, social outing, symposium dinner and access to draft proceedings. The student discount is made possible by the symposium's industrial sponsors.

Registration link:
Instructions: Please click on "Sign up" on the upper left of the sign up page. Choose "Standard" on the first sign-up page unless you are a Ph.D., Master's or bachelor's student enrolled at an accredited university. You will need to check the "Do you give us permission to record your presentation and share the recording?" box. Symposium dinner and outing (social event) are included in the registration fee; so please check the corresponding boxes. If you know already now that you cannot attend the social event or the symposium dinner, you can help our planning by unchecking the corresponding boxes. (If you change your mind later on we'll do our best to accommodate you.) You will need to fill out "Dietary Restrictions?" twice, on the 'Sign Up' page and on the 'Orderer' page that follows it. If you have no dietary restrictions, please write "None". If you know your university's EU VAT number, fill it into the CVR field on the 'Orderer' page; if not, don't worry about it. (The VAT number may help your university recover Danish VAT included in the registration fee.) Finally check all required boxes in the payment process and pay. You will get a registration confirmation and will subsequently get up-to-date information about IFL 2022 by email.


General chair
Fritz Henglein
Program chair
Martin Elsman
Communications chair
Troels Henriksen
Program commitee
  • Laura M. Castro, Universidade da Coruña, Spain
  • David Christiansen, Haskell Foundation
  • Martin Elsman, University of Copenhagen, Denmark (chair)
  • Matthew Fluet, Rochester Institute of Technology, USA
  • Clemens Grelck, Universiteit van Amsterdam, The Netherlands
  • Zhenjiang Hu, Peking University, China
  • Robin Kaarsgaard, University of Edinburgh, Scotland
  • Gabriele Keller, Utrecht University, The Netherlands
  • Oleg Kiselyov, Tohoku University, Japan
  • Neil Mitchell, Facebook
  • Stefan Monnier, Universite de Montreal, Canada
  • Magnus Myreen, Chalmers University, Sweden
  • Cyrus Omar, University of Michigan, USA
  • Romain Péchoux, University of Lorraine, Inria, France
  • Rinus Plasmeijer, Radboud University, The Netherlands
  • Morten Rhiger, Roskilde University, Denmark
  • Peter van Roy, Catholic University of Louvain, Belgium
  • Olin Shivers, Northeastern University, USA
  • Peter Thiemann, University of Freiburg, Germany
  • Marcos Viera, Universidad de la República, Uruguay
  • Meng Wang, University of Bristol, UK

Previous editions of IFL

Industrial sponsors

We are grateful for the financial support by Meta (silver), Well-typed (bronze) and Functional Copenhageners (bronze). Their contributions have made it possible to keep registration fees below actual costs, in particular for students.

Would you like to sponsor the industrial keynote and reception Friday, 15-17 CET, to make it open and free to the public (up to the capacity of Celebration Auditorium)?

We provide multiple options for you.

Bronze (DKK 5000):
Your logo and link on the IFL 2022 website and in symposium materials; your roll-up or poster in the social space outside the symposium lecture room; one free registration (which can be donated to somebody else). Your sponsorship contributes to discounted student registration by partially covering on-site food and facility costs for students.
Silver (DKK 10000), industrial reception sponsor:
All of Bronze, plus: Named sponsor of industrial reception; with sponsor presentation (in lecture room or social space) at the beginning of the industrial reception.
Please contact Fritz Henglein.


This call-for-papers is an adaptation and evolution of content from previous instances of IFL. We are grateful to prior organisers for their work, which is reused here.