DHD UHac/DHD Program
This is the current program for the Dutch HUG Day. It may still change.
|9:30||Coffee and Tea|
|10:00||Welcome||Sean Leather, Stef Joosten|
|10:15||WebSockets||Jasper Van der Jeugt|
|11:15||Model Checking Abstract Syntax Trees||Pascal Hof|
|DotFS||Paul van der Walt, Sjoerd Timmer|
|Snap and Gruze||Kevin Jardine|
|Case Study Invitation||Jurriaan Hage|
|12:15||Lunch (Provided by Ordina)|
|13:15||Haskell in Practice||Stef Joosten, Martijn Schrage|
|14:15||TBD||José Pedro Magalhães|
|Holes in GHC||Thijs Alkemade|
|Applicative Regular Expressions||Roman Cheplyaka|
|15:30||Depart for UHac|
1.1 Supporting Different Versions of the WebSockets Protocol
Jasper Van der Jeugt (Ghent)
The Haskell websockets library allows you to write WebSocket-enabled servers in Haskell, bidirectional communication with the browser. However, browsers and their related specifications change fast, and there are different versions of the WebSockets protocol. This talk discusses a type-safe technique which disallows the programmer from using primitives not available in the chosen version, while still allowing the latest features.
1.2 Building your own Haskell ecosystem
Erik Hesselink (Silk)
When you develop a lot of different Haskell packages that work together, managing all these packages and their versions can be difficult. In this talk, I'll explain how we deal with this at Silk. I will show how to use Hackage 2.0 to build your own internal package repository, how to use cabal-dev to manage installed packages, and show a tool for bumping package versions. Together, this makes working on large amounts of packages with multiple people much easier.
1.3 Model Checking Abstract Syntax Trees
Pascal Hof (TU Dortmund)
Model checking turned out to be a useful tool for the analysis of programs. Usually one transforms abstract syntax trees to control flow graphs, which offer a abstract representation of program behavior. Whenever one is not focused on program behavior but on structural properties of the program (e.g. semantic analysis of a compiler), model checking the abstract syntax tree comes in handy. My talk introduces a problem, which can be solved using model checking abstract syntax trees. Additionally, different approaches for a implementation will be discussed.
1.4 DotFS - Or How Fred Solved His Config Clutter
Paul van der Walt (UU), Sjoerd Timmer (UU)
Everyone who has more than one account on Linux/Unix/OS X systems knows how hard is can be to keep track of all the different config files in your home directory. .vimrc, .muttrc, .hgrc, .screenrc, .bashrc, and .xinitrc are just a few, but we're sure you can come up with many more yourself. Imagine how wonderful your life could be if you just had an easy tool to keep track of different versions of all these files on all your machines. We argue that traditional version control systems on their own are not up the task and we provide an alternative.
1.5 Snap and Gruze
Snap and Gruze. Developing an astronomy application using Snap and an experimental entity-attribute-value store for Haskell.
1.6 Invitation to Participate in a Functional Programming Case Study
Jurriaan Hage (UU)
I want to invite you to participate in an experiment in Haskell. In this experiment we are going to pit HaRe (the Haskell Refactorer) against Holmes (my plagiarism detector). The goal is to find out how much time somebody needs to refactor a Haskell program into something that is not recognizable by Holmes as plagiarism. We shall be looking at two groups of study: experienced programmers (we shall pretend they are paid for by newbies to make their assignments for them, and to do so without starting from scratch), and the newbies themselves. This experiment is a collaboration with Simon Thompson of Kent. He will take charge of the newbies, my task is to perform the experiment with experienced Haskell programmers, which is why I am now seeking for participants.
1.7 Haskell in Practice: How Haskell Has Been Used in a (Paid) IT Project.
Stef Joosten (Ordina), Martijn Schrage (Oblomov Systems)
This presentation shows how new thinking helps the judiciary to gain control over and to reduce cost in a landscape of many different IT systems that serve the courts of law in the Netherlands.
Although Haskell plays a role outside the limelight, the results have become possible because of a tool, Ampersand, which has been built in Haskell.
The presentation is accompanied by a brief demonstration.
1.8 fclabels: First Class Record Labels for Haskell
Sebastiaan Visser (Silk)
Haskell's record system for algebraic datatypes uses labels as accessors for fields within constructors. Record labels can be used for both selection and modification of individual fields within value, but only selection can be composed in a natural way. The special syntax for updates makes composing modifications very cumbersome. The fclabels package tries to solve this problem by implementing field accessors as first class Haskell values instead of special syntax. Labels are implemented as lenses and can easily be composed for both selection and modification. To avoid boilerplate labels can be derived using Template Haskell. This talk will give a brief introduction into the usage of the library and will show a bit of the inner workings as a bridge to future extensions.
1.9 Holes in GHC
Thijs Alkemade (UU)
This will be a demonstration of work-in-progress on adding holes for type-based debugging with GHC. See the GHC Trac page for details.
1.10 Applicative Regular Expressions
In this short talk I am going to describe the regex-applicative project:
- what it is about
- how it compares to other parsing combinator libraries
- its current state and unsolved problems
I'll be glad to accept any help during UHac.