| Safe Haskell | Safe |
|---|---|
| Language | Haskell2010 |
Patience.Map
Description
This module provides a lossless way to do
diffing between two Maps, and ways to
manipulate the diffs.
Synopsis
- data Delta a
- data M
- diff :: (Eq a, Ord k) => Map k a -> Map k a -> Map k (Delta a)
- getSame :: Eq a => Delta a -> Maybe a
- getOld :: Delta a -> Maybe a
- getNew :: Delta a -> Maybe a
- getDelta :: Delta a -> Maybe (a, a)
- getOriginal :: M -> Delta a -> Maybe a
- getOriginals :: Delta a -> (Maybe a, Maybe a)
- isSame :: Eq a => Delta a -> Bool
- isOld :: Delta a -> Bool
- isNew :: Delta a -> Bool
- isDelta :: Delta a -> Bool
- toSame :: Eq a => Map k (Delta a) -> Map k a
- toOld :: Map k (Delta a) -> Map k a
- toNew :: Map k (Delta a) -> Map k a
- toDelta :: Map k (Delta a) -> Map k (a, a)
- toOriginal :: M -> Map k (Delta a) -> Map k a
- toOriginals :: Map k (Delta a) -> (Map k a, Map k a)
- mapSame :: Eq a => (a -> b) -> Map k (Delta a) -> Map k b
- mapOld :: (a -> b) -> Map k (Delta a) -> Map k b
- mapNew :: (a -> b) -> Map k (Delta a) -> Map k b
- mapSame' :: Eq a => (a -> a) -> Map k (Delta a) -> Map k (Delta a)
- mapOld' :: (a -> a) -> Map k (Delta a) -> Map k (Delta a)
- mapNew' :: (a -> a) -> Map k (Delta a) -> Map k (Delta a)
Types
The result of a diff of an entry within two Maps.
In two Maps m1 and m2, when performing a diff, this type encodes the following situations:
Same key, different values: Stores the two values in the Delta constructor.
Same key, same values: Stores the value in the Same constructor.
Key exists in m1 but not m2: Stores the value in the Old constructor.
Key exists in m2 but not m1: Stores the value in the New constructor.
This behaviour ensures that we don't lose any information, meaning
we can reconstruct either of the original Map k a from a Map k (Delta a).
(Note that this slightly differs from diff, which does not
care about the possibility of reconstruction).
Instances
Diffing
Case analysis on Delta
Construction of special maps from a diff
toDelta :: Map k (Delta a) -> Map k (a, a) Source #
Retrieve only the DeltaUnit values out of the diff map.
Mapping
mapSame' :: Eq a => (a -> a) -> Map k (Delta a) -> Map k (Delta a) Source #
Map over all the Same values, preserving the
remaining values in the map.