# incremental: incremental update interface [](https://hackage.haskell.org/package/incremental)  [](https://discord.gg/DG93Tgs) This package provides a typeclass for incremental updates and diffing. ```haskell class Incremental a where -- | the difference type type Delta a -- | @'maybe' a ('patch' a) ('diff' b a) ≡ b@ patch :: a -> Delta a -> a -- | returns 'Nothing' when there is no update diff :: a -> a -> Maybe (Delta a) ```