-- |Gets the next id for a column in the idx set, and
-- |returns that id, and the updated list.
getnid :: Int -> IdxSet -> (Idx, IdxSet)
getnid n s = let id = (s !! n) in (id, nid n [] s)
getnid :: Int -> IdxSet -> (Idx, IdxSet)
getnid n s = let id = (s !! n) in (id, nid n [] s)
getnid n s = let id = (s !! n) in (id, nid n [] s)