Great post, I remember when I first picked up a functional language (it was OCaml for me) I was perplexed by the sheer number of concepts that were all new to m

Great post, I remember when I first picked up a functional language (it was OCaml for me) I was perplexed by the sheer number of concepts that were all new to me. Currying, tail recursion, higher order functions, combinators, functors, lenses, the list goes on and on. These concepts can be translated outside of the functional realm to a certain extent but the way that many of these functional languages embrace these ideas as part of the paradigm was refreshing to say the least. Since you were collecting comments/suggestions: I urge you to take a look at the zipper data structure if you haven't already, they are applicable to what you are working on and are a good intellectual exercise on their own :) In addition, I haven't had the time to go over all of your code but I don't see you mentioned circular dependencies for your tool, is that a feature that is yet to be implemented? In fact this project can probably benefit from drawing ideas from garbage collection techniques since conceptually I think they are very similar.