refactor and function name cleanup

(oops, I had a calcMerge and a calc_merge!)

Git/UpdateIndex.hs

@@ -7,9 +7,11 @@
 
 module Git.UpdateIndex (
 	Streamer,
-	stream_update_index,
-	ls_tree,
-	update_index_line,
+	pureStreamer,
+	streamUpdateIndex,
+	lsTree,
+	updateIndexLine,
+	stageSymlink
 ) where
 
 import System.Cmd.Utils
@@ -19,14 +21,19 @@ import Git
 import Git.Types
 import Git.Command
 import Git.FilePath
+import Git.HashObject
 
 {- Streamers are passed a callback and should feed it lines in the form
  - read by update-index, and generated by ls-tree. -}
 type Streamer = (String -> IO ()) -> IO ()
 
+{- A streamer with a precalculated value. -}
+pureStreamer :: String -> Streamer
+pureStreamer s = \streamer -> streamer s
+
 {- Streams content into update-index from a list of Streamers. -}
-stream_update_index :: Repo -> [Streamer] -> IO ()
-stream_update_index repo as = do
+streamUpdateIndex :: Repo -> [Streamer] -> IO ()
+streamUpdateIndex repo as = do
 	(p, h) <- hPipeTo "git" (toCommand $ gitCommandLine params repo)
 	fileEncoding h
 	forM_ as (stream h)
@@ -39,14 +46,24 @@ stream_update_index repo as = do
 			hPutStr h s
 			hPutStr h "\0"
 
-{- Gets the current tree for a ref. -}
-ls_tree :: Ref -> Repo -> Streamer
-ls_tree (Ref x) repo streamer = mapM_ streamer =<< pipeNullSplit params repo
+{- A streamer that adds the current tree for a ref. Useful for eg, copying
+ - and modifying branches. -}
+lsTree :: Ref -> Repo -> Streamer
+lsTree (Ref x) repo streamer = mapM_ streamer =<< pipeNullSplit params repo
 	where
 		params = map Param ["ls-tree", "-z", "-r", "--full-tree", x]
 
 {- Generates a line suitable to be fed into update-index, to add
  - a given file with a given sha. -}
-update_index_line :: Sha -> BlobType -> TopFilePath -> String
-update_index_line sha filetype file =
+updateIndexLine :: Sha -> BlobType -> TopFilePath -> String
+updateIndexLine sha filetype file =
 	show filetype ++ " blob " ++ show sha ++ "\t" ++ getTopFilePath file
+
+{- A streamer that adds a symlink to the index. -}
+stageSymlink :: FilePath -> String -> Repo -> IO Streamer
+stageSymlink file linktext repo = do
+	line <- updateIndexLine
+		<$> hashObject BlobObject linktext repo
+		<*> pure SymlinkBlob
+		<*> toTopFilePath file repo
+	return $ pureStreamer line