It’s dangerous to go alone

Posts filed under Haskell

  1. Arrow is more than Strong and Category

    Several people have claimed that Haskell’s Arrow class is exactly the intersection of Category and Strong, but this argument ignores the Arrow laws. I demonstrate a type which is has lawful instances of Strong and Category which cannot be made into an Arrow in a consistent way. (2017-07-18)

  2. More on Free Applicative Functors

    Since free applicative functors are free, does that mean they are monads over indexed types? Also, can we squeeze out any more performance? (2013-06-12)

  3. Prompt Monads are Free

    A brief look at Prompt monads, showing that they are free monads, that Prompt is a monad over indexed types, and how it can be used to build composable components. (2013-06-07)

  4. Free Applicative Functors in Haskell

    Can we find a way to make an applicative functor for any type constructor? It turns out, methods are already known—but I didn’t know that when I started, so I found my own way. One that turns out to have much better performance. (2013-05-27)

  5. Parameterized monads vs monads over indexed types

    Parameterized monads are a known way of extending the monadic interface. As an alternative, Conor McBride suggested using monads over indexed types. How do these approaches compare? (2012-07-29)

  6. Syntax highlighting for Haskell in BBEdit 8.0

    I’ve put together a Codeless Language Module for BBEdit 8.0 that implements basic syntax highlighting for Haskell. (2004-08-31)

  7. Category extras

    The Haskell package no one demanded! (2004-07-26)