Join the sums.

src/Renderer/Patch.hs

@@ -24,7 +24,7 @@ patch :: Renderer a String
 patch diff sources = mconcat $ showHunk sources <$> hunks diff sources
 
 -- | A hunk in a patch, including the offset, changes, and context.
-data Hunk a = Hunk { offset :: (Sum Int, Sum Int), changes :: [Change a], trailingContext :: [Row a] }
+data Hunk a = Hunk { offset :: Join (Sum Int), changes :: [Change a], trailingContext :: [Row a] }
   deriving (Eq, Show)
 
 -- | A change in a patch hunk, along with its preceding context.
@@ -32,16 +32,16 @@ data Change a = Change { context :: [Row a], contents :: [Row a] }
   deriving (Eq, Show)
 
 -- | The number of lines in the hunk before and after.
-hunkLength :: Hunk a -> (Sum Int, Sum Int)
+hunkLength :: Hunk a -> Join (Sum Int)
 hunkLength hunk = mconcat $ (changeLength <$> changes hunk) <> (rowLength <$> trailingContext hunk)
 
 -- | The number of lines in change before and after.
-changeLength :: Change a -> (Sum Int, Sum Int)
+changeLength :: Change a -> Join (Sum Int)
 changeLength change = mconcat $ (rowLength <$> context change) <> (rowLength <$> contents change)
 
 -- | The number of lines in the row, each being either 0 or 1.
-rowLength :: Row a -> (Sum Int, Sum Int)
-rowLength (Row a b) = (lineLength a, lineLength b)
+rowLength :: Row a -> Join (Sum Int)
+rowLength (Row a b) = pure lineLength <*> Join (a, b)
 
 -- | The length of the line, being either 0 or 1.
 lineLength :: Line a -> Sum Int
@@ -78,27 +78,27 @@ header :: Join SourceBlob -> Hunk a -> String
 header blobs hunk = "diff --git a/" ++ pathA ++ " b/" ++ pathB ++ "\n" ++
   "index " ++ oidA ++ ".." ++ oidB ++ "\n" ++
   "@@ -" ++ show offsetA ++ "," ++ show lengthA ++ " +" ++ show offsetB ++ "," ++ show lengthB ++ " @@\n"
-  where (lengthA, lengthB) = join bimap getSum $ hunkLength hunk
-        (offsetA, offsetB) = join bimap getSum $ offset hunk
+  where (lengthA, lengthB) = runJoin . fmap getSum $ hunkLength hunk
+        (offsetA, offsetB) = runJoin . fmap getSum $ offset hunk
         (pathA, pathB) = runJoin $ path <$> blobs
         (oidA, oidB) = runJoin $ oid <$> blobs
 
 -- | Render a diff as a series of hunks.
 hunks :: Renderer a [Hunk (SplitDiff a Info)]
-hunks diff blobs = hunksInRows (1, 1) . fst $ splitDiffByLines diff (0, 0) (before, after)
+hunks diff blobs = hunksInRows (Join (1, 1)) . fst $ splitDiffByLines diff (0, 0) (before, after)
   where
     (before, after) = runJoin $ source <$> blobs
 
 -- | Given beginning line numbers, turn rows in a split diff into hunks in a
 -- | patch.
-hunksInRows :: (Sum Int, Sum Int) -> [Row (SplitDiff a Info)] -> [Hunk (SplitDiff a Info)]
+hunksInRows :: Join (Sum Int) -> [Row (SplitDiff a Info)] -> [Hunk (SplitDiff a Info)]
 hunksInRows start rows = case nextHunk start rows of
   Nothing -> []
   Just (hunk, rest) -> hunk : hunksInRows (offset hunk <> hunkLength hunk) rest
 
 -- | Given beginning line numbers, return the next hunk and the remaining rows
 -- | of the split diff.
-nextHunk :: (Sum Int, Sum Int) -> [Row (SplitDiff a Info)] -> Maybe (Hunk (SplitDiff a Info), [Row (SplitDiff a Info)])
+nextHunk :: Join (Sum Int) -> [Row (SplitDiff a Info)] -> Maybe (Hunk (SplitDiff a Info), [Row (SplitDiff a Info)])
 nextHunk start rows = case nextChange start rows of
   Nothing -> Nothing
   Just (offset, change, rest) -> let (changes, rest') = contiguousChanges rest in Just (Hunk offset (change : changes) $ take 3 rest', drop 3 rest')
@@ -110,7 +110,7 @@ nextHunk start rows = case nextChange start rows of
 
 -- | Given beginning line numbers, return the number of lines to the next
 -- | the next change, and the remaining rows of the split diff.
-nextChange :: (Sum Int, Sum Int) -> [Row (SplitDiff a Info)] -> Maybe ((Sum Int, Sum Int), Change (SplitDiff a Info), [Row (SplitDiff a Info)])
+nextChange :: Join (Sum Int) -> [Row (SplitDiff a Info)] -> Maybe (Join (Sum Int), Change (SplitDiff a Info), [Row (SplitDiff a Info)])
 nextChange start rows = case changeIncludingContext leadingContext afterLeadingContext of
   Nothing -> Nothing
   Just (change, afterChanges) -> Just (start <> mconcat (rowLength <$> skippedContext), change, afterChanges)