Visualising control and data structures helps building an intuition. This is exactly what the latest addition to our tutorial Learning Haskell is all about — well, that and having fun with graphics.

Our latest chapter Spirals, Snowflakes & Trees: Recursion in Pictures starts by introducing a simple line graphics interface backed by the Haskell vector graphics package Rasterific. From there, we work our way up from simple spiral structures over Koch snowflakes to Pythagorean Trees. It is a lot of fun experimenting with these structures in Haskell for Mac playgrounds, but users of other platforms can also join in by using Rasterific in the conventional way.

If you have got ideas for other fractal structures based on our simple line graphics interface, please send the Haskell code to and we will publish it on this blog.