Beautiful Power Series

I’m getting better at Haskell, or at least that’s what I choose to believe. Anyway, I recently joined Haskell-cafe, one of the e-mail distribution lists, and I found this great thread where Kim-Ee Yeoh links to a gorgeous article Power serious: power series in ten one-liners.

In the article Doug McIlroy, in a few one-liners, defines infinite power series for trigonometric functions exploiting the power of Haskell’s lazy evaluation.

As a teaser, this is the code for the sin and cos series1,

How awesome is that!

I have to find some time to play with the code. It makes me happy that this can be written so simply and beautifully, we must be doing something right.

  1. 1 int is integration and it can also be trivially defined.