[ANN] interval-patterns-0.8.2

I wanted to include the intervals in my Adjacency type in order to maintain the invariant that the arguments of the constructor of Adjacency a are in increasing order. This allows implementing interval operations in terms of the adjacency:

difference ::
  forall x. (Ord x) => Interval x -> Interval x -> Maybe (OneOrTwo (Interval x))
difference i1 i2 = case adjacency i1 i2 of
  Before i _ -> Just (One i)
  Meets i _ _ -> Just (One i)
  Overlaps i _ _ -> Just (One i)
  Starts{} -> Nothing
  During{} -> Nothing
  Finishes i _ -> Just (One i)
  Identical{} -> Nothing
  FinishedBy{} -> Nothing
  Contains i _ k -> Just (Two i k)
  StartedBy _ j -> Just (One j)
  OverlappedBy _ _ k -> Just (One k)
  MetBy _ _ k -> Just (One k)
  After _ j -> Just (One j)