ModuleDiff-1.0.2Haskell2010

Data.Algorithm.Diff

This is an implementation of the diff algorithm as described in An O(ND) Difference Algorithm and Its Variations (1986) http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.4.6927. For inputs of size O(N) with the number of differences D it has O(ND) time and O(D^2) space complexity.

2 types
4 values

PackageDiff-1.0.2
Exports6
LanguageHaskell2010
LicenceBSD-3-Clause
SourceDiff.hs

typetype Diff a = PolyDiff a a

This is PolyDiff specialized so both sides are the same type.

datadata PolyDiff a b

A value is either from the First list, the Second or from Both. Both contains both the left and right values, in case you are using a form of equality that doesn't check all data (for example, if you are using a newtype to only perform equality on side of a tuple).

Constructors

First a
Second b
Both a b

Instances4Bifunctor, Functor, Eq, Show

Bifunctor PolyDiffDefined in Diff-1.0.2 · Data.Algorithm.Diff
Functor (PolyDiff a)Defined in Diff-1.0.2 · Data.Algorithm.Diff
(Eq a, Eq b) => Eq (PolyDiff a b)Defined in Diff-1.0.2 · Data.Algorithm.Diff
(Show a, Show b) => Show (PolyDiff a b)Defined in Diff-1.0.2 · Data.Algorithm.Diff

Comparing lists for differences

2 declarations

valuegetDiff :: Eq a => [a] -> [a] -> [Diff a]

Takes two lists and returns a list of differences between them. This is getDiffBy with == used as predicate.

> getDiff ["a","b","c","d","e"] ["a","c","d","f"]
[Both "a" "a",First "b",Both "c" "c",Both "d" "d",First "e",Second "f"]
> getDiff "abcde" "acdf"
[Both 'a' 'a',First 'b',Both 'c' 'c',Both 'd' 'd',First 'e',Second 'f']

valuegetDiffBy :: (a -> b -> Bool) -> [a] -> [b] -> [PolyDiff a b]

A form of getDiff with no Eq constraint. Instead, an equality predicate is taken as the first argument.

Finding chunks of differences

2 declarations

valuegetGroupedDiff :: Eq a => [a] -> [a] -> [Diff [a]]

Takes two lists and returns a list of differences between them, grouped into chunks. This is getGroupedDiffBy with == used as predicate.

> getGroupedDiff "abcde" "acdf"
[Both "a" "a",First "b",Both "cd" "cd",First "e",Second "f"]

valuegetGroupedDiffBy :: (a -> b -> Bool) -> [a] -> [b] -> [PolyDiff [a] [b]]