teideal glic deisbhéalach

If you use Fedora 8, GHC 6.8.1 will be in the stable repository within 24 hours or so. I’ve also pushed a compatible build of gtk2hs 0.9.12.1 to the stable repository.

Upgrading my laptop from F-7 to F-8 yesterday was painless, so I’ve been able to verify that the latest version of GHC works smoothly. I’ve pushed the built packages to the F-8 testing repository, and will bump them to release in about a week.
If you’re feeling impatient, you can download the final RPMs from the [...]

This evening, I’ll be speaking at the peculiar but fun Ignite SF. My talk is notionally about functional programming, but it’s really about imposing constraints on yourself, and what you can get out of it.

When debugging or profiling Haskell code, it’s common practice to pepper it with cost centre annotations, often called SCC (for strongly connected component set cost centre) annotations. If you compile a program using ghc -prof -auto-all, this causes all of the top-level names in every module you compile to automatically be annotated with their names, [...]

Tim Bray has recently been writing about a simple log file processing task, giving his efforts the (decidedly peculiar) name of Wide Finder. The task at hand is to count popular links in an Apache log file. Here’s my two minutes’ worth of hat in the ring, in Haskell. > main = do > args <- getArgs > [...]

I’ve spent a few spare hours here and there working on a pure Haskell interface to MySQL recently. On the principle that perhaps someone else might want to join in the fun, I’ve published a darcs repository already (see the link above for more details):

darcs get http://darcs.serpentine.com/mysql

There are a few reasons I’m doing this. One [...]

Some months ago, I wrote a Python implementation of Daniel Lemire’s Weighted Slope One collaborative filtering algorithm. Steve Jenson sent me a pointer to his Scala implementation last week, but his code is a straight port of the Python version, not using any of Scala’s tasty functional crunchiness. In an idle period the other evening, I [...]

A few days ago, I wrote a Haskell library for building and working with suffix trees. It builds a suffix tree lazily, so even though its performance is O(n log n) on large input strings, it often has linear performance for many applications.
The implementation is simple and easy to read; the API is well-documented and [...]

Here’s a great quote from Yaron Minsky about the use of types in functional programs.
[...] most of the advantage of types in a language like ML comes from completely vanilla uses of the type system. One of our programming maxims at Jane Street is to “make illegal states unrepresentable”. Algebraic datatypes, parametric polymorphism and abstraction [...]

I’ve been running test releases of Fedora 7, and lately the final release, for a number of months on my fairly new Lenovo Thinkpad X60. Here’s a brief summary of my experiences. I’ve been using Fedora since 0.92 (Taroon), and while I’ve generally been happy with it, F7 is not exactly a model of stability or sleekness. Here’s a [...]