Category Archives: haskell

New ICFP functional pearl on subtracting bijections

Kenny Foner and I have a paper accepted to ICFP on subtracting bijections. Here’s the basic problem: suppose you have a bijection between two sum types, , and another bijection . Of course and must have the same size, but … Continue reading

Posted in combinatorics, haskell, writing | Tagged , , , , , | 5 Comments

Ertugrul Söylemez: 1985-2018

I do not know many details, but IRC user mupf joined the #haskell-ops channel yesterday to tell us that Ertugrul Söylemez died unexpectedly on May 12. This is a great loss for the Haskell community. Going variously by mm_freak, ertes, … Continue reading

Posted in haskell, meta | Tagged , , , , | 4 Comments

Future of Coding podcast interview

I recently did an interview with my friend and former student Steve Krouse for his Future of Coding podcast. I think I still agree with almost everything I said, and I didn’t say anything too embarrassing, so if you want … Continue reading

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Parametricity for Bifunctor

I’ve begun work to add Bifunctor, Bifoldable, and Bitraversable to the Typeclassopedia. While thinking and writing about Bifunctor I ended up proving some “folklore” results for my own satisfaction, and decided someone might possibly find it useful if I formally … Continue reading

Posted in haskell, math | Tagged , , , , , | 3 Comments

New baby, and Haskell Alphabet

My wife and I just had a baby! If you missed seeing me at ICFP, this is why. In honor of my son’s birth (he will need to learn the alphabet and Haskell soon)—and at the instigation of Kenny Foner—I … Continue reading

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The Typeclassopedia is now up-to-date

The title pretty much says it all: I have finally finished (I hope) updating the Typeclassopedia to reflect various recent changes to the language and standard libraries (such as the AMP and BBP/FTP). Along the way I also added more … Continue reading

Posted in haskell, writing | Tagged , , , , | 10 Comments

Advent of code #16 solution: an algebra of bitstrings

I had fun this past December solving Advent of Code problems in Haskell. I was particularly proud of my solution to one particular problem involving generating and processing large bitstrings, which I’d like to share here. I think it really … Continue reading

Posted in haskell | Tagged , , , , , , | 2 Comments