Category Archives: haskell

diagrams repos now mirrored on github!

I was quite excited when I learned that Owen Stephens was working on a two-way darcs-git bridge for his Google Summer of Code project. You see, I’m one of those holdouts who, despite acknowledging that github is pretty cool and … Continue reading

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I have just uploaded a new package to Hackage which defines the constant . Now if you wish to use in your program you can just cabal install tau and then import Math.Tau (tau), and be assured that you are … Continue reading

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Unbound now supports “set” binders and GADTs

I have just uploaded version 0.3 of the Unbound library (and version 0.5 of RepLib). This version adds support for two major new features: The new permbind and setbind functions create binders that are alpha-equivalent “up to permutation”. For example, … Continue reading

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Idempotent Template Haskell

Yesterday I was looking for a way to have some Template Haskell code generate a definition for a certain identifier if and only if such a definition did not already exist. Essentially I want to be able to call the … Continue reading

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Hac phi 3!

Hac phi 3 is in full swing now: almost 30 people showed up for the first day of hacking yesterday and more are expected today! I’ve posted a few pictures here — more to come.

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Bit-rotted text adventure EDSL free to a good home

In early 2008 I started working on a Haskell embedded domain-specific language for authoring text adventure games. It didn’t get all that far since I didn’t know a whole lot about either text adventure games or Haskell. But I think … Continue reading

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Themes on Streams, Part II

In a previous post I claimed that comonad structures on R -> a are in one-to-one correspondence with monoid structures on R. In this post and the next I’ll justify that claim. Characterizing comonads on R -> a Suppose we … Continue reading

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