Compares strings to produce change lists. diffChars and diffLines are provided.

The currently-implemented algorithm is the Hunt-McIlroy algorithm.

Pull requests optimizing the existing algorithm are welcome.

Pull requests implementing alternative diff algorithms (notably, the Patience algorithm) are also welcome.

import Diff (..)

diffChars "abc" "aBcd"
  -- [ NoChange "a", Changed "b" "B", NoChange "c", Added "d" ]


original = """Brian
Sohie
Oscar
Stella
Takis
"""

changed = """BRIAN
Stella
Frosty
Takis
"""

diffLines original changed
  -- [ Changed "Brian\nSohie\nOscar\n" "BRIAN\n"
  -- , NoChange "Stella\n"
  -- , Added "Frosty\n"
  -- , NoChange "Takis\n"
  -- ]

This package should still be considered unstable: while the returned list of changes will always be correct, the specific the list of changes and the way the changes are grouped/combined, as well as the performance characteristics of the diff algorithm may change in future releases of this package.