Data.Patch.Class

The interface for types which represent changes made to other types

Documentation

class Patch p where

A Patch type represents a kind of change made to a datastructure.

If an instance of Patch is also an instance of Semigroup, it should obey the law that applyAlways (f <> g) == applyAlways f . applyAlways g.

Associated Types

type PatchTarget p :: *

Methods

apply :: p -> PatchTarget p -> Maybe (PatchTarget p)

Apply the patch p a to the value a. If no change is needed, return Nothing.

Instances

Patch (Identity a)

Identity can be used as a Patch that always fully replaces the value

Defined in Data.Patch.Class

Associated Types

type PatchTarget (Identity a) :: Type

Methods

apply :: Identity a -> PatchTarget (Identity a) -> Maybe (PatchTarget (Identity a))

Patch (PatchIntMap a)

Apply the insertions or deletions to a given IntMap.

Defined in Data.Patch.IntMap

Associated Types

type PatchTarget (PatchIntMap a) :: Type

Methods

apply :: PatchIntMap a -> PatchTarget (PatchIntMap a) -> Maybe (PatchTarget (PatchIntMap a))

Additive p => Patch (AdditivePatch p)

Defined in Data.Patch

Associated Types

type PatchTarget (AdditivePatch p) :: Type

Methods

apply :: AdditivePatch p -> PatchTarget (AdditivePatch p) -> Maybe (PatchTarget (AdditivePatch p))

Ord k => Patch (PatchMap k v)

Apply the insertions or deletions to a given Map.

Defined in Data.Patch.Map

Associated Types

type PatchTarget (PatchMap k v) :: Type

Methods

apply :: PatchMap k v -> PatchTarget (PatchMap k v) -> Maybe (PatchTarget (PatchMap k v))

Ord k => Patch (PatchMapWithMove k v)

Apply the insertions, deletions, and moves to a given Map

Defined in Data.Patch.MapWithMove

Associated Types

type PatchTarget (PatchMapWithMove k v) :: Type

Methods

apply :: PatchMapWithMove k v -> PatchTarget (PatchMapWithMove k v) -> Maybe (PatchTarget (PatchMapWithMove k v))

GCompare k2 => Patch (PatchDMap k2 v)

Apply the insertions or deletions to a given DMap.

Defined in Data.Patch.DMap

Associated Types

type PatchTarget (PatchDMap k2 v) :: Type

Methods

apply :: PatchDMap k2 v -> PatchTarget (PatchDMap k2 v) -> Maybe (PatchTarget (PatchDMap k2 v))

GCompare k2 => Patch (PatchDMapWithMove k2 v)

Apply the insertions, deletions, and moves to a given DMap.

Defined in Data.Patch.DMapWithMove

Associated Types

type PatchTarget (PatchDMapWithMove k2 v) :: Type

Methods

apply :: PatchDMapWithMove k2 v -> PatchTarget (PatchDMapWithMove k2 v) -> Maybe (PatchTarget (PatchDMapWithMove k2 v))

applyAlways :: Patch p => p -> PatchTarget p -> PatchTarget p

Apply a Patch; if it does nothing, return the original value

composePatchFunctions :: (Patch p, Semigroup p) => (PatchTarget p -> p) -> (PatchTarget p -> p) -> PatchTarget p -> p

Like '(.)', but composes functions that return patches rather than functions that return new values. The Semigroup instance for patches must apply patches right-to-left, like '(.)'.