ekmett/intervals — pull request #13 by dmcclean (2014-03-27 02:30:13+00:00)
Title: Changed clamp to return Nothing for an empty interval.

I think it is probably a good idea to make the answer here explicitly a `Maybe`. That case is potentially very sneaky otherwise.

Alternatively it might be the case that this function only usefully exists in the `NonEmpty` module; I think it is the case that all my use sites of it will be switching to `NonEmpty`.