-- | -- Module: Data.Geo.Jord.Quantity -- Copyright: (c) 2018 Cedric Liegeois -- License: BSD3 -- Maintainer: Cedric Liegeois <ofmooseandmen@yahoo.fr> -- Stability: experimental -- Portability: portable -- -- Classes for working with quantities. -- module Data.Geo.Jord.Quantity ( Quantity(..) ) where -- | Something that can be added or subtracted. class (Eq a) => Quantity a where add, sub :: a -> a -> a zero :: a