Overview/important dates

For CIS 194 you will complete a final project which will tie together some of the things you have learned and give you some practical Haskell development experience. The expectation is for you to spend around 10-15 hours working on the project. Here are some important dates:

Get started early!


Here is a document explaining a few things relevant to Haskell programming in the large.


You may work by yourself, or in groups of up to three students. Note, however, that projects for groups of three will be held to somewhat higher standards than those for individuals or pairs. Groups of five are right out.

There are two types of projects you may complete:

  1. Application/library

    For your project you may write some sort of Haskell application or library which does something fun/useful/interesting. Your imagination is the limit. Some possibilities/suggestions include:

    • A program to play a game (like tic-tac-toe, Connect 4, othello, gomoku, poker, mancala, …) against the user.

    • A program to solve puzzles like sudoku or kenken.

    • A program to generate random mazes and let the user interactively solve them, or to solve mazes input by the user.

    • An implementation of some interesting data structure like red-black trees, 2-3-4 trees, binomial heaps, or Fibonacci heaps.

    • An parser and interpreter for a small programming language, such as a while language.

    • A raytracer.

    • Create a web site using hakyll.

    • Take an interesting program you have written in some other language, and figure out how to port/re-implement it in idiomatic Haskell.

    • Whatever else your creativity suggests!

  2. Open-source contribution

    For your project you may choose an open-source library or application on Hackage to contribute to. Contributions may include bug fixes, new features, and/or documentation. Here are a few suggestions—these are projects whose authors/maintainers have indicated that there would be good ways for beginning Haskell students to contribute. (But you are free to work on any project you like, as long as you can find a reasonable way to contribute.) If you want to try contributing to one of these projects, you should contact the relevant person(s) and discuss it with them prior to submitting your project proposal.

    Note: if you are thinking of making an open-source contribution you may turn in your proposal by Monday, March 25.

    Open-source projects students have contributed to in prior years include a package to efficiently compute prime numbers using a mutable-array-based sieve and Haskell bindings to the Kinect.

    • snowdrift.coop (Contact: )

      I’m working with some people putting together http://snowdrift.coop, which is built on Yesod. We’ve got a lot of tasks on our plate, of various sizes and scopes and time-lines, and if students are interested I’d be happy to work with you to come up with some appropriate projects, and do as much hand holding as is necessary thereafter.

    • taffybar (Contact: )

      I have an Xmonad status bar called taffybar. It is meant for xmonad, but does not truly require it. It uses gtk2hs and is basically just a horizontal list of widgets. Each widget is entirely separate from the others, and is just a gtk widget that can do whatever it wants. The codebase is actually pretty simple as long as they are familiar with doing IO in Haskell.

      A few possible ideas of varying complexity:

      • Add a new backend to the weather widget (e.g., Weather Underground). This would involve parsing whatever response Weather Underground returns for its queries.

        Possibly on the high end for what they are prepared for

      • Add weather icons for current weather conditions (rainy, cloudy, etc)

        Probably on the easier end - it would just require conditionally adding the appropriate icon whenever the weather changes.

      • Add a launcher widget. It would launch programs typed into a text box (possibly triggered by a keystroke or always visible). That step is very easy. More interesting work could be done in adding tab completion for commands, or possibly modal commands.

        A modal command system might be worth its own project separately from a widget if it was plugin based. For example, a ‘note’ plugin would add a command like

        note NAME CONTENT...

        where the command would save CONTENT to a file named NAME somewhere sensible. Launching programs could just be another plugin.

        This can be as complex as desired and is still useful in its simpler stages.

    • EPUB reader for pandoc (Contact: )

      I’ll just resuggest what I suggested last year:

      …implement an EPUB reader for pandoc.

      This would have to unzip the input file, look in the metadata to see what’s there, extract the chapters and parse them with pandoc’s HTML reader, and do something with images and the like (maybe make them into data: URIs – see Text.Pandoc.SelfContained).

      It would be handy to be able to convert an epub directly into to markdown, HTML, LaTeX, docx, or PDF. And the pieces are all pretty much there in pandoc already.

      One fun application I see for this would be a command line tool that converts the epub to texinfo, then converts this into info and uses info to browse the epub. Essentially: a cheap command-line epub browser.

    • hnn examples (Contact: )

      My suggestion may sound a bit odd, but if they’re looking for a challenging but still simple enough project, I’d love for people to test out the new version of hnn (not yet released, but on github and make something fun with it. I’d love to mentor this and add things to the library altogether as they progress and give some feedback. The biggest issue with that proposal is that they either have to know a bit about neural networks before or must be able to learn very quickly. This can however be compensated by that warm feeling you have when your neural net finally does what you want it to.

    • MoCap (Contact: )

      Not something very big, but if someone wants to get hands on working with Parsec I started developing a library to work with motion capture (MoCap) data. I need to parse MoCap data for my bachelor’s thesis so I decided to do it in a way that might benefit others. On the other hand, I don’t need all the info in the file for my work and this project is not my priority, so one of the students could extend the parser to parse the sections of the file it currently ignores. Also more file types support would be nice since I am only developing a parser for ASF/AMC files. The project is very new, small and is located here: https://github.com/netogallo/MoCap . I can give you more details of the tasks that could be done (essentially creating a parser fore more sections of the file, define ADTs to represent those sections, semantic validation of files, better error messages, etc.) and I would be willing to exchange e-mails and answer questions to students if necessary.

    • diagrams (Contact: Brent Yorgey)

      diagrams is a framework for creating vector graphics by writing Haskell code which is a description of the graphics you would like. There are many small tasks which could be done: creating more examples for the gallery, adding some specialized module(s) to the diagrams-contrib package (e.g. a module for drawing representations of Turing machines, or for visualizing sorting algorithms, or …), adding support for rounded polygons and paths, grid layout, or gradients

      Note: if you would like to contribute to diagrams, I will happily provide guidance and so on, but in order to make things fair only the TAs will grade your final project. Hence this is not a way to get an easy A.

Project proposal

You must submit a project proposal by Monday, March 18 (unless you are thinking about working on an open-source contribution, in which case you have until Monday, March 25 in order to have time to communicate with the maintainer(s). This gives us a chance to discuss your proposal and ensure it will make a suitable project. You are encouraged to submit your proposal earlier than March 18 if you already have an idea. You should also feel free to submit several project proposals if you would like help deciding which is most suitable.

To submit your proposal, send an email of a few paragraphs to me (byorgey at cis) with the subject “CIS 194 final project proposal”. Try to answer the questions: What do you propose to do? What do you hope to learn from the project? What are some concrete goals, i.e. how will we judge the success of your project?


Sometime during the week of April 8-12 or thereabouts, you should schedule a meeting with one of Brent, Zach, or Adi to show off the progress you have made on your project, get any guidance or help you might need, and discuss your plans for completing the project. Note that the checkpoint meeting will constitute part of your final project grade, though there’s no need to stress out about it. Concretely, by the checkpoint you should:

The purpose of the meetings is twofold: to make sure you get started on your project before the last minute, and to provide a convenient space for you to ask questions and get some direction and feedback.

Final submission

Final submissions are due by Tuesday, April 23. Extensions to the final deadline will be cheerfully granted, but you must ask for one by Tuesday, April 16 (one week in advance). Simply choose your own deadline—up to and including the last day of finals, May 7—and that will be your new deadline.

Your final submission should consist of any and all code you have written, along with a document describing your project (a simple text file is fine). The document should contain

You may submit your project in one of two ways:

Grading will be as follows: