Category Archives: haskell

Monad transformers: a cautionary tale

Posted on April 29, 2013 by

When writing the code in my previous post, I wanted to have a monad which combined the ability to generate random numbers with the ability to fail. Naturally, I decided to use RandT Maybe. But when I tried to write … Continue reading →

Posted in haskell | Tagged , , , | Leave a comment

Random binary trees with a size-limited critical Boltzmann sampler

Posted on April 25, 2013 by

Today I’d like to talk about generating random trees. First, some imports and such (this post is literate Haskell). > {-# LANGUAGE GeneralizedNewtypeDeriving #-} > > module BoltzmannTrees where > > import Control.Applicative > import Control.Arrow ((&&&)) > import Control.Lens … Continue reading →

Posted in combinatorics, haskell, math, species | Tagged , , , , , | 7 Comments

Introducing diagrams-haddock

Posted on March 23, 2013 by

I am quite pleased to announce the release of diagrams-haddock, a tool enabling you to easily include programmatically generated diagrams in your Haddock documentation. Why might you want to do this? “A picture is worth a thousand words”—in many instances … Continue reading →

Posted in diagrams, haskell, writing | Tagged , , , | 3 Comments

BlogLiterately 0.6

Posted on March 10, 2013 by

I’m very proud to announce the release of BlogLiterately version 0.6, a tool for formatting and uploading blog posts, including syntax highlighting, generation of ghci sessions, LaTeX support, automatic image uploading, and more. tl;dr: Instead of cumbersomely specifying all options … Continue reading →

Posted in haskell, writing | Tagged , , | Leave a comment

The Dawn of Software Engineering

Posted on January 13, 2013 by

The Dawn of Software Engineering: From Turing to DijkstraEdgar G. Daylight Edgar sent me a review copy of his book a while back—it made for quite interesting reading and gave me new perspective on the historical origins of my field. … Continue reading →

Posted in haskell | 3 Comments

Diagrams 0.6

Posted on December 11, 2012 by

I am pleased to announce the release of version 0.6 of diagrams, a full-featured framework and embedded domain-specific language for declarative drawing. Check out the gallery for examples of what it can do! Highlights of this release include: Diagrams now … Continue reading →

Posted in diagrams, haskell, projects | Tagged , , , | 6 Comments

foldr is made of monoids

Posted on November 5, 2012 by

> import Data.Monoid In his recent blog post What is foldr made of?, Tom Ellis made the clever observation that foldr is equivalent in power to the combination of map and compose, where > compose :: [a -> a] -> … Continue reading →

Posted in haskell, math | Tagged , , , , | 15 Comments

Using multiple versions of GHC in parallel with GNU stow

Posted on November 1, 2012 by

Do any of the following apply to you? You sometimes hack on GHC. You sometimes want to try out an unreleased GHC version. You maintain a library and want to make sure it builds with several different versions of GHC. … Continue reading →

Posted in haskell | Tagged , , , | 10 Comments

Creating documents with embedded diagrams

Posted on August 28, 2012 by

If you read my recent post about type algebra, you may have wondered how I got all those nice images in there. Surely creating the images and then inserting them into the post by hand would be rather tedious! Indeed, … Continue reading →

Posted in diagrams, haskell, projects, writing | Tagged , , , , , , , , , | 2 Comments

BlogLiterately 0.5.2 release, with improved image uploading

Posted on August 26, 2012 by

Just a quick note to say that I’ve just released version 0.5.2 of BlogLiterately. (For more information about what it does, see what I’ve written about previous releases here and here, and the documentation.) The new version keeps track of … Continue reading →

Posted in haskell, writing | Tagged , , | Leave a comment