Category Archives: projects

Lightweight invertible enumerations in Haskell

Posted on July 5, 2019 by

In a previous post I introduced a new Haskell library for enumerations (now on Hackage as simple-enumeration). The Data.Enumeration module defines a type Enumeration a, represented simply by a function Integer -> a which picks out the value of type … Continue reading →

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Lightweight, efficiently sampleable enumerations in Haskell

Posted on May 14, 2019 by

For another project I’m working on, I needed a way to enumerate and randomly sample values from various potentially infinite collections. There are plenty of packages in this space, but none of them quite fit my needs: universe (and related … Continue reading →

Posted in combinatorics, haskell, projects | Tagged , , , , | 10 Comments

Idea for a physics-based rolling ball puzzle game

Posted on March 14, 2019 by

For quite a while I’ve had this idea for a cool game, and had vague intentions to learn some game/physics framework well enough to make it, but I’ve finally admitted that this is never going to happen. Instead I’ll just … Continue reading →

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A (work in progress) translation of Joyal’s original paper on species

Posted on February 13, 2018 by

tl;dr: I’m working on an English translation, with additional commentary, of Joyal’s 1981 paper introducing the concept of combinatorial species. Collaboration and feedback welcome! Back when I was writing my PhD thesis on combinatorial species, I was aware that André … Continue reading →

Posted in combinatorics, projects, species, writing | Tagged , , , , , , | 6 Comments

Off the Beaten Track: Explaining Type Errors

Posted on January 21, 2018 by

Last week I gave a talk at Off the Beaten Track 2018 about something that Richard Eisenberg, Harley Eades and I have been thinking about recently: namely, how to generate good interactive error explanations for programmers, especially for type errors. … Continue reading →

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MonadRandom 0.5 released

Posted on January 3, 2017 by

I’m happy to announce the release of MonadRandom-0.5, a package which provides a convenient monadic interface for random number generation in the style of transformers and mtl: a Rand monad (essentially a state monad that threads through a generator), a … Continue reading →

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MonadRandom 0.5 and mwc-random: feedback wanted

Posted on November 16, 2016 by

Since 2013 or so I have been the maintainer of the MonadRandom package, which provides an mtl-style type class for monads with support for generation of pseudorandom values, along with a concrete random monad transformer RandT. As of this writing … Continue reading →

Posted in haskell, projects | Tagged , | 9 Comments