I'm going to make what should be an uncontroversial statement: if you don't understand and use monads, you are at best a quarter of a Haskell programmer. A corollary of this is that, since using monad transformers is the only (or at least the approved) way to use two or more monads together, if you don't understand and use monad transformers you ( Read more... )

I'm in the middle of writing up a research proposal for a postdoc position I'm applying for. I've had enough of categorification for a while, and it struck me that doing formal semantics for a simple language in the APL family (J, K, A+, Matlab...) could be both Fun and Interesting. Some poking around on Google and MathSciNet suggests that nobody's ( Read more... )

While trying to do one of the exercises from SICP, I wanted to apply and to a list. Now, I could have used fold, but it seemed a bit of a waste given that Scheme's and is variadic: what I needed was an equivalent of Perl's func(@list_of_args) idiom, or Python and Ruby's func(*list). So, inspired by the syntax for variadic function definitions, I ( Read more... )

Current status on some of my long-term projects:

Thesis: Up to ( 36 pages )

The APL Lesson: If all your problems can be solved with short programs, it doesn't matter how hard it is to write or maintain long ones.

Smith's (First) Law: Any sufficiently large test suite for a program written in a dynamic language will contain an ad-hoc, informally-specified, bug-ridden, slow, patchy implementation of half of the Haskell type ( Read more... )

I've fixed the J Mandelbrot set program. Needless to say, the fix took precisely three characters :-)

[By the way, did anyone read that post? Does anyone else think J is interesting? Or did you just see a wall of punctuation and get scared off?]

( The gory details )

I've been learning the programming language J recently, and in the course of my studies came across this example program by Ewart Shaw, to draw an ASCII-graphics Mandelbrot set:
{&'#.' @ (2:<|) @ ((+*:)^:400 0:) (18 %~ i:_20) j.~/ 28 %~ _59+i.75 It embodies so many J features and techniques that I'm going to analyse it here as ( an introduction to the language. )

The relationship between human languages and programming languages is interesting to me. In general, programming languages are a lot simpler (which is great, because it makes it easier to learn lots of them): they also have rather less vocabulary (but that's OK, because you're actively encouraged to make up your own). We talk about programming " ( Read more... )