reorder repo parameters last

Many functions took the repo as their first parameter. Changing it
consistently to be the last parameter allows doing some useful things with
currying, that reduce boilerplate.

In particular, g <- gitRepo is almost never needed now, instead
use inRepo to run an IO action in the repo, and fromRepo to get
a value from the repo.

This also provides more opportunities to use monadic and applicative
combinators.

1 files changed, 51 insertions, 49 deletions

diff --git a/Git.hs b/Git.hs
index b05c3b2d5..6fb6e8361 100644
--- a/Git.hs
+++ b/Git.hs
@@ -188,13 +188,13 @@ repoRemoteName Repo { remoteName = Just name } = Just name
 repoRemoteName _ = Nothing
 
 {- Sets the name of a remote. -}
-repoRemoteNameSet :: Repo -> String -> Repo
-repoRemoteNameSet r n = r { remoteName = Just n }
+repoRemoteNameSet :: String -> Repo -> Repo
+repoRemoteNameSet n r = r { remoteName = Just n }
 
 {- Sets the name of a remote based on the git config key, such as
    "remote.foo.url". -}
-repoRemoteNameFromKey :: Repo -> String -> Repo
-repoRemoteNameFromKey r k = repoRemoteNameSet r basename
+repoRemoteNameFromKey :: String -> Repo -> Repo
+repoRemoteNameFromKey k = repoRemoteNameSet basename
 	where
 		basename = join "." $ reverse $ drop 1 $
 				reverse $ drop 1 $ split "." k
@@ -280,8 +280,8 @@ workTree Repo { location = Unknown } = undefined
  - is itself a symlink). But, if the cwd is "/tmp/repo/subdir",
  - it's best to refer to "../foo".
  -}
-workTreeFile :: Repo -> FilePath -> IO FilePath
-workTreeFile repo@(Repo { location = Dir d }) file = do
+workTreeFile :: FilePath -> Repo -> IO FilePath
+workTreeFile file repo@(Repo { location = Dir d }) = do
 	cwd <- getCurrentDirectory
 	let file' = absfile cwd
 	unless (inrepo file') $
@@ -296,7 +296,7 @@ workTreeFile repo@(Repo { location = Dir d }) file = do
 		absfile c = fromMaybe file $ secureAbsNormPath c file
 		inrepo f = absrepo `isPrefixOf` f
 		bad = error $ "bad repo" ++ repoDescribe repo
-workTreeFile repo _ = assertLocal repo $ error "internal"
+workTreeFile _ repo = assertLocal repo $ error "internal"
 
 {- Path of an URL repo. -}
 urlPath :: Repo -> String
@@ -350,23 +350,23 @@ urlAuthPart a Repo { location = Url u } = a auth
 urlAuthPart _ repo = assertUrl repo $ error "internal"
 
 {- Constructs a git command line operating on the specified repo. -}
-gitCommandLine :: Repo -> [CommandParam] -> [CommandParam]
-gitCommandLine repo@(Repo { location = Dir _ } ) params =
+gitCommandLine :: [CommandParam] -> Repo -> [CommandParam]
+gitCommandLine params repo@(Repo { location = Dir _ } ) =
 	-- force use of specified repo via --git-dir and --work-tree
 	[ Param ("--git-dir=" ++ gitDir repo)
 	, Param ("--work-tree=" ++ workTree repo)
 	] ++ params
-gitCommandLine repo _ = assertLocal repo $ error "internal"
+gitCommandLine _ repo = assertLocal repo $ error "internal"
 
 {- Runs git in the specified repo. -}
-runBool :: Repo -> String -> [CommandParam] -> IO Bool
-runBool repo subcommand params = assertLocal repo $
-	boolSystem "git" $ gitCommandLine repo $ Param subcommand : params
+runBool :: String -> [CommandParam] -> Repo -> IO Bool
+runBool subcommand params repo = assertLocal repo $
+	boolSystem "git" $ gitCommandLine (Param subcommand : params) repo
 
 {- Runs git in the specified repo, throwing an error if it fails. -}
-run :: Repo -> String -> [CommandParam] -> IO ()
-run repo subcommand params = assertLocal repo $
-	runBool repo subcommand params
+run :: String -> [CommandParam] -> Repo -> IO ()
+run subcommand params repo = assertLocal repo $
+	runBool subcommand params repo
 		>>! error $ "git " ++ show params ++ " failed"
 
 {- Runs a git subcommand and returns its output, lazily. 
@@ -374,26 +374,26 @@ run repo subcommand params = assertLocal repo $
  - Note that this leaves the git process running, and so zombies will
  - result unless reap is called.
  -}
-pipeRead :: Repo -> [CommandParam] -> IO L.ByteString
-pipeRead repo params = assertLocal repo $ do
-	(_, h) <- hPipeFrom "git" $ toCommand $ gitCommandLine repo params
+pipeRead :: [CommandParam] -> Repo -> IO L.ByteString
+pipeRead params repo = assertLocal repo $ do
+	(_, h) <- hPipeFrom "git" $ toCommand $ gitCommandLine params repo
 	hSetBinaryMode h True
 	L.hGetContents h
 
 {- Runs a git subcommand, feeding it input.
  - You should call either getProcessStatus or forceSuccess on the PipeHandle. -}
-pipeWrite :: Repo -> [CommandParam] -> L.ByteString -> IO PipeHandle
-pipeWrite repo params s = assertLocal repo $ do
-	(p, h) <- hPipeTo "git" (toCommand $ gitCommandLine repo params)
+pipeWrite :: [CommandParam] -> L.ByteString -> Repo -> IO PipeHandle
+pipeWrite params s repo = assertLocal repo $ do
+	(p, h) <- hPipeTo "git" (toCommand $ gitCommandLine params repo)
 	L.hPut h s
 	hClose h
 	return p
 
 {- Runs a git subcommand, feeding it input, and returning its output.
  - You should call either getProcessStatus or forceSuccess on the PipeHandle. -}
-pipeWriteRead :: Repo -> [CommandParam] -> L.ByteString -> IO (PipeHandle, L.ByteString)
-pipeWriteRead repo params s = assertLocal repo $ do
-	(p, from, to) <- hPipeBoth "git" (toCommand $ gitCommandLine repo params)
+pipeWriteRead :: [CommandParam] -> L.ByteString -> Repo -> IO (PipeHandle, L.ByteString)
+pipeWriteRead params s repo = assertLocal repo $ do
+	(p, from, to) <- hPipeBoth "git" (toCommand $ gitCommandLine params repo)
 	hSetBinaryMode from True
 	L.hPut to s
 	hClose to
@@ -402,13 +402,13 @@ pipeWriteRead repo params s = assertLocal repo $ do
 
 {- Reads null terminated output of a git command (as enabled by the -z 
  - parameter), and splits it. -}
-pipeNullSplit :: Repo -> [CommandParam] -> IO [String]
-pipeNullSplit repo params = map L.unpack <$> pipeNullSplitB repo params
+pipeNullSplit :: [CommandParam] -> Repo -> IO [String]
+pipeNullSplit params repo = map L.unpack <$> pipeNullSplitB params repo
 
 {- For when Strings are not needed. -}
-pipeNullSplitB :: Repo -> [CommandParam] -> IO [L.ByteString]
-pipeNullSplitB repo params = filter (not . L.null) . L.split '\0' <$>
-	pipeRead repo params
+pipeNullSplitB ::[CommandParam] -> Repo -> IO [L.ByteString]
+pipeNullSplitB params repo = filter (not . L.null) . L.split '\0' <$>
+	pipeRead params repo
 
 {- Reaps any zombie git processes. -}
 reap :: IO ()
@@ -448,15 +448,15 @@ shaSize = 40
 
 {- Commits the index into the specified branch, 
  - with the specified parent refs. -}
-commit :: Repo -> String -> String -> [String] -> IO ()
-commit g message newref parentrefs = do
+commit :: String -> String -> [String] -> Repo -> IO ()
+commit message newref parentrefs repo = do
 	tree <- getSha "write-tree" $ asString $
-		pipeRead g [Param "write-tree"]
+		pipeRead [Param "write-tree"] repo
 	sha <- getSha "commit-tree" $ asString $
-		ignorehandle $ pipeWriteRead g
+		ignorehandle $ pipeWriteRead
 			(map Param $ ["commit-tree", tree] ++ ps)
-			(L.pack message)
-	run g "update-ref" [Param newref, Param sha]
+			(L.pack message) repo
+	run "update-ref" [Param newref, Param sha] repo
 	where
 		ignorehandle a = snd <$> a
 		asString a = L.unpack <$> a
@@ -478,13 +478,13 @@ configRead r = assertLocal r $ error "internal"
 hConfigRead :: Repo -> Handle -> IO Repo
 hConfigRead repo h = do
 	val <- hGetContentsStrict h
-	configStore repo val
+	configStore val repo
 
 {- Stores a git config into a repo, returning the new version of the repo.
  - The git config may be multiple lines, or a single line. Config settings
  - can be updated inrementally. -}
-configStore :: Repo -> String -> IO Repo
-configStore repo s = do
+configStore :: String -> Repo -> IO Repo
+configStore s repo = do
 	let repo' = repo { config = configParse s `M.union` config repo }
 	rs <- configRemotes repo'
 	return $ repo' { remotes = rs }
@@ -507,13 +507,11 @@ configRemotes repo = mapM construct remotepairs
 		filterkeys f = filterconfig (\(k,_) -> f k)
 		remotepairs = filterkeys isremote
 		isremote k = startswith "remote." k && endswith ".url" k
-		construct (k,v) = do
-			r <- genRemote repo v
-			return $ repoRemoteNameFromKey r k
+		construct (k,v) = repoRemoteNameFromKey k <$> genRemote v repo
 
 {- Generates one of a repo's remotes using a given location (ie, an url). -}
-genRemote :: Repo -> String -> IO Repo
-genRemote repo = gen . calcloc
+genRemote :: String -> Repo -> IO Repo
+genRemote s repo = gen $ calcloc s
 	where
 		filterconfig f = filter f $ M.toList $ config repo
 		gen v	
@@ -549,8 +547,8 @@ configTrue :: String -> Bool
 configTrue s = map toLower s == "true"
 
 {- Returns a single git config setting, or a default value if not set. -}
-configGet :: Repo -> String -> String -> String
-configGet repo key defaultValue = 
+configGet :: String -> String -> Repo -> String
+configGet key defaultValue repo = 
 	M.findWithDefault defaultValue key (config repo)
 
 {- Access to raw config Map -}
@@ -558,8 +556,8 @@ configMap :: Repo -> M.Map String String
 configMap = config
 
 {- Efficiently looks up a gitattributes value for each file in a list. -}
-checkAttr :: Repo -> String -> [FilePath] -> IO [(FilePath, String)]
-checkAttr repo attr files = do
+checkAttr :: String -> [FilePath] -> Repo -> IO [(FilePath, String)]
+checkAttr attr files repo = do
 	-- git check-attr needs relative filenames input; it will choke
 	-- on some absolute filenames. This also means it will output
 	-- all relative filenames.
@@ -574,7 +572,11 @@ checkAttr repo attr files = do
         hClose toh
 	(map topair . lines) <$> hGetContents fromh
 	where
-		params = gitCommandLine repo [Param "check-attr", Param attr, Params "-z --stdin"]
+		params = gitCommandLine 
+				[ Param "check-attr"
+				, Param attr
+				, Params "-z --stdin"
+				] repo
 		topair l = (file, value)
 			where 
 				file = decodeGitFile $ join sep $ take end bits