Rewriting most functions to return a pair Fmt.t * Fmt.t is more difficult to maintain and to get the expected output, maybe Josh is right and we should wait until we ave an intermediate ast representation for this? @Julow

Yes that is becoming a mess. What we need is not an intermediate ast but a box representation that can either be manipulated or that handle docking of boxes cleanly.

Alright, I'm closing this one in the meantime, we should restart from scratch once we have better boxes.

FTR, the 'intermediate ast' suggested in #406 isn't an ast, but a tree structure representing the (eventual) nesting of boxes. With such a structure, I think that nesting could be manipulated, and docking handled uniformly.