Author Archives: Brent

About Brent

Assistant Professor of Computer Science at Hendrix College. Functional programmer, mathematician, teacher, pianist, follower of Jesus.

Competitive programming in Haskell: BFS, part 2 (alternative APIs)

Posted on October 18, 2021 by Brent

In my last post, I showed how we can solve Modulo Solitaire (and hopefully other BFS problems as well) using a certain API for BFS, which returns two functions: one, level :: v -> Maybe Int, gives the level (i.e. … Continue reading →

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Competitive programming in Haskell: BFS, part 1

Posted on October 14, 2021 by Brent

In a previous post, I challenged you to solve Modulo Solitaire. In this problem, we are given a starting number and are trying to reach in as few moves as possible. At each move, we may pick one of up … Continue reading →

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Swarm: a lot can happen in a week

Posted on October 1, 2021 by Brent

It’s been about a week since I put out an announcement and call for collaboration on a new game, Swarm. Since then, the response has been fantastic: lots of people have tried it out, a few have even streamed themselves … Continue reading →

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Swarm: preview and call for collaboration

Posted on September 23, 2021 by Brent

For about a month now I have been working on building a game1, tentatively titled Swarm. It’s nowhere near finished, but it has at least reached a point where I’m not embarrassed to show it off. I would love to … Continue reading →

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Competitive programming in Haskell: Codeforces Educational Round 114

Posted on September 21, 2021 by Brent

Yesterday morning I competed in Educational Round 114 on codeforces.com, using only Haskell. It is somewhat annoying since it does not support as many Haskell libraries as Open Kattis (e.g. no unordered-containers, split, or vector); but on the other hand, … Continue reading →

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Automatically updated, cached views with lens

Posted on September 17, 2021 by Brent

Recently I discovered a nice way to deal with records where certain fields of the record cache some expensive function of other fields, using the lens library. I very highly doubt I am the first person to ever think of … Continue reading →

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Competitive programming in Haskell: Kadane’s algorithm

Posted on September 9, 2021 by Brent

I will be giving a talk on competitive programming in Haskell tomorrow, September 10, at Haskell Love. You should attend! It’s free! In my last competitive programming post, I challenged you to solve Purple Rain. We are presented with a … Continue reading →

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Implementing Hindley-Milner with the unification-fd library

Posted on September 8, 2021 by Brent

For a current project, I needed to implement type inference for a Hindley-Milner-based type system. (More about that project in an upcoming post!) If you don’t know, Hindley-Milner is what you get when you add polymorphism to the simply typed … Continue reading →

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Competitive programming in Haskell: monoidal accumulation

Posted on August 11, 2021 by Brent

In my last competitive programming post, I challenged you to solve Please, Go First. In that problem, we are presented with a hypothetical scenario with people waiting in a queue for a ski lift. Each person is part of a … Continue reading →

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Types versus sets in math and programming languages

Posted on June 24, 2021 by Brent

For several years I have been designing and implementing a functional teaching language especially for use in the context of a Discrete Mathematics course. The idea is for students to be exposed to some functional and statically-typed programming early in … Continue reading →

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