splatterhunks

[William Lee Irwin III]

-- This program takes patch filenames as arguments and splits the patch
-- files up on a hunk-by-hunk basis. I have found this useful for Linux
-- kernel development, and perhaps others might find it useful in
-- similar contexts where patches are the primary method of communication.

module Main where
import System
import List

main = getArgs >>= mapM_ splatterHunkFile

splatterHunkFile file = mapM_ (\(f,ss) -> writeFile f (unlines ss)) . zip (map (((reverse . takeWhile (/= '/') . reverse $ file)++).("-"++).show) [1..]) . splatterHunks =<< readFile file

splatterHunks ss = map (map unlines) $ zipWith (\s -> map (s:)) (map head . (splitList "diff") $ lines ss) (map (splitList "@@") . (splitList "diff") $ lines ss)

splitList prefix ss = map ($ss) $ zipWith (\m n -> (if n >= 0 then take (n - m) else id) . drop m) (map fst . filter (\(n,s) -> isPrefixOf prefix s) $ zip [0..] ss) (tail (map fst . filter (\(n,s) -> isPrefixOf prefix s) $ zip [0..] ss) ++ [-1])