Ternary Search Trie in Erlang

The last few months I've not done a terrible amount hobby programming; I spent much of the time interviewing (successfully!) at Rackspace and, since arriving in San Antonio, have been busy learning the team code-base. There were a few hobby projects I finished during February-April period, the one I'm most pleased with is a ternary search trie, a data-structure described by Bentley and Sedgewick in their 1996 paper Fast Algorithms for Searching and Sorting Strings, among other places.

I wrote an implementation from the paper with the intention of writing a Scrabble bot around it, but I'll probably not finish that project. I'm releasing the code, extracted from the Scrabble bot under the MIT license. Find it on Github. Novel features:

• extensively typed
• uses proper to test algorithm properties

Problems:

• works only on strings, as typed
• never stress tested nor optimized for performance
• the work of idle hands, not necessarily careful

Patches welcome!