remove Params constructor from Utility.SafeCommand

This removes a bit of complexity, and should make things faster
(avoids tokenizing Params string), and probably involve less garbage
collection.

In a few places, it was useful to use Params to avoid needing a list,
but that is easily avoided.

Problems noticed while doing this conversion:

	* Some uses of Params "oneword" which was entirely unnecessary
	  overhead.
	* A few places that built up a list of parameters with ++
	  and then used Params to split it!

Test suite passes.

Git/CheckAttr.hs

@@ -30,7 +30,8 @@ checkAttrStart attrs repo = do
   where
 	params =
 		[ Param "check-attr" 
-		, Params "-z --stdin"
+		, Param "-z"
+		, Param "--stdin"
 		] ++ map Param attrs ++
 		[ Param "--" ]
 

Git/CheckIgnore.hs

@@ -43,7 +43,10 @@ checkIgnoreStart repo = ifM supportedGitVersion
   where
 	params =
 		[ Param "check-ignore" 
-		, Params "-z --stdin --verbose --non-matching"
+		, Param "-z"
+		, Param "--stdin"
+		, Param "--verbose"
+		, Param "--non-matching"
 		]
 	repo' = repo { gitGlobalOpts = filter (not . pathspecs) (gitGlobalOpts repo) }
 	pathspecs (Param "--literal-pathspecs") = True

Git/DiffTree.hs

@@ -78,7 +78,13 @@ getdiff command params repo = do
 	(diff, cleanup) <- pipeNullSplit ps repo
 	return (parseDiffRaw diff, cleanup)
   where
-	ps = command : Params "-z --raw --no-renames -l0" : params
+	ps = 
+		command :
+		Param "-z" :
+		Param "--raw" :
+		Param "--no-renames" :
+		Param "-l0" :
+		params
 
 {- Parses --raw output used by diff-tree and git-log. -}
 parseDiffRaw :: [String] -> [DiffTreeItem]

Git/LsFiles.hs

@@ -35,14 +35,23 @@ import System.Posix.Types
 
 {- Scans for files that are checked into git at the specified locations. -}
 inRepo :: [FilePath] -> Repo -> IO ([FilePath], IO Bool)
-inRepo l = pipeNullSplit $ Params "ls-files --cached -z --" : map File l
+inRepo l = pipeNullSplit $ 
+	Param "ls-files" :
+	Param "--cached" :
+	Param "-z" :
+	Param "--" :
+	map File l
 
 {- Scans for files at the specified locations that are not checked into git. -}
 notInRepo :: Bool -> [FilePath] -> Repo -> IO ([FilePath], IO Bool)
 notInRepo include_ignored l repo = pipeNullSplit params repo
   where
-	params = [Params "ls-files --others"] ++ exclude ++
-		[Params "-z --"] ++ map File l
+	params = concat
+		[ [ Param "ls-files", Param "--others"]
+		, exclude
+		, [ Param "-z", Param "--" ]
+		, map File l
+		]
 	exclude
 		| include_ignored = []
 		| otherwise = [Param "--exclude-standard"]
@@ -50,28 +59,51 @@ notInRepo include_ignored l repo = pipeNullSplit params repo
 {- Finds all files in the specified locations, whether checked into git or
  - not. -}
 allFiles :: [FilePath] -> Repo -> IO ([FilePath], IO Bool)
-allFiles l = pipeNullSplit $ Params "ls-files --cached --others -z --" : map File l
+allFiles l = pipeNullSplit $
+	Param "ls-files" :
+	Param "--cached" :
+	Param "--others" :
+	Param "-z" :
+	Param "--" :
+	map File l
 
 {- Returns a list of files in the specified locations that have been
  - deleted. -}
 deleted :: [FilePath] -> Repo -> IO ([FilePath], IO Bool)
 deleted l repo = pipeNullSplit params repo
   where
-	params = [Params "ls-files --deleted -z --"] ++ map File l
+	params =
+		Param "ls-files" :
+		Param "--deleted" :
+		Param "-z" :
+		Param "--" :
+		map File l
 
 {- Returns a list of files in the specified locations that have been
  - modified. -}
 modified :: [FilePath] -> Repo -> IO ([FilePath], IO Bool)
 modified l repo = pipeNullSplit params repo
   where
-	params = [Params "ls-files --modified -z --"] ++ map File l
+	params = 
+		Param "ls-files" :
+		Param "--modified" :
+		Param "-z" :
+		Param "--" :
+		map File l
 
 {- Files that have been modified or are not checked into git (and are not
  - ignored). -}
 modifiedOthers :: [FilePath] -> Repo -> IO ([FilePath], IO Bool)
 modifiedOthers l repo = pipeNullSplit params repo
   where
-	params = [Params "ls-files --modified --others --exclude-standard -z --"] ++ map File l
+	params = 
+		Param "ls-files" :
+		Param "--modified" :
+		Param "--others" :
+		Param "--exclude-standard" :
+		Param "-z" :
+		Param "--" :
+		map File l
 
 {- Returns a list of all files that are staged for commit. -}
 staged :: [FilePath] -> Repo -> IO ([FilePath], IO Bool)
@@ -85,7 +117,7 @@ stagedNotDeleted = staged' [Param "--diff-filter=ACMRT"]
 staged' :: [CommandParam] -> [FilePath] -> Repo -> IO ([FilePath], IO Bool)
 staged' ps l = pipeNullSplit $ prefix ++ ps ++ suffix
   where
-	prefix = [Params "diff --cached --name-only -z"]
+	prefix = [Param "diff", Param "--cached", Param "--name-only", Param "-z"]
 	suffix = Param "--" : map File l
 
 type StagedDetails = (FilePath, Maybe Sha, Maybe FileMode)
@@ -93,7 +125,7 @@ type StagedDetails = (FilePath, Maybe Sha, Maybe FileMode)
 {- Returns details about files that are staged in the index,
  - as well as files not yet in git. Skips ignored files. -}
 stagedOthersDetails :: [FilePath] -> Repo -> IO ([StagedDetails], IO Bool)
-stagedOthersDetails = stagedDetails' [Params "--others --exclude-standard"]
+stagedOthersDetails = stagedDetails' [Param "--others", Param "--exclude-standard"]
 
 {- Returns details about all files that are staged in the index. -}
 stagedDetails :: [FilePath] -> Repo -> IO ([StagedDetails], IO Bool)
@@ -106,7 +138,7 @@ stagedDetails' ps l repo = do
 	(ls, cleanup) <- pipeNullSplit params repo
 	return (map parse ls, cleanup)
   where
-	params = Params "ls-files --stage -z" : ps ++ 
+	params = Param "ls-files" : Param "--stage" : Param "-z" : ps ++ 
 		Param "--" : map File l
 	parse s
 		| null file = (s, Nothing, Nothing)
@@ -135,7 +167,12 @@ typeChanged' ps l repo = do
 	currdir <- getCurrentDirectory
 	return (map (\f -> relPathDirToFileAbs currdir $ top </> f) fs, cleanup)
   where
-	prefix = [Params "diff --name-only --diff-filter=T -z"]
+	prefix = 
+		[ Param "diff"
+		, Param "--name-only"
+		, Param "--diff-filter=T"
+		, Param "-z"
+		]
 	suffix = Param "--" : (if null l then [File "."] else map File l)
 
 {- A item in conflict has two possible values.
@@ -166,7 +203,12 @@ unmerged l repo = do
 	(fs, cleanup) <- pipeNullSplit params repo
 	return (reduceUnmerged [] $ catMaybes $ map parseUnmerged fs, cleanup)
   where
-	params = Params "ls-files --unmerged -z --" : map File l
+	params = 
+		Param "ls-files" :
+		Param "--unmerged" :
+		Param "-z" :
+		Param "--" :
+		map File l
 
 data InternalUnmerged = InternalUnmerged
 	{ isus :: Bool

Git/LsTree.hs

@@ -37,13 +37,26 @@ lsTree t repo = map parseLsTree
 	<$> pipeNullSplitZombie (lsTreeParams t) repo
 
 lsTreeParams :: Ref -> [CommandParam]
-lsTreeParams t = [ Params "ls-tree --full-tree -z -r --", File $ fromRef t ]
+lsTreeParams t =
+	[ Param "ls-tree"
+	, Param "--full-tree"
+	, Param "-z"
+	, Param "-r"
+	, Param "--"
+	, File $ fromRef t
+	]
 
 {- Lists specified files in a tree. -}
 lsTreeFiles :: Ref -> [FilePath] -> Repo -> IO [TreeItem]
 lsTreeFiles t fs repo = map parseLsTree <$> pipeNullSplitStrict ps repo
   where
-	ps = [Params "ls-tree --full-tree -z --", File $ fromRef t] ++ map File fs
+	ps =
+		[ Param "ls-tree"
+		, Param "--full-tree"
+		, Param "-z"
+		, Param "--"
+		, File $ fromRef t
+		] ++ map File fs
 
 {- Parses a line of ls-tree output.
  - (The --long format is not currently supported.) -}

Git/Repair.hs

@@ -99,7 +99,7 @@ retrieveMissingObjects :: FsckResults -> Maybe FilePath -> Repo -> IO FsckResult
 retrieveMissingObjects missing referencerepo r
 	| not (foundBroken missing) = return missing
 	| otherwise = withTmpDir "tmprepo" $ \tmpdir -> do
-		unlessM (boolSystem "git" [Params "init", File tmpdir]) $
+		unlessM (boolSystem "git" [Param "init", File tmpdir]) $
 			error $ "failed to create temp repository in " ++ tmpdir
 		tmpr <- Config.read =<< Construct.fromAbsPath tmpdir
 		stillmissing <- pullremotes tmpr (remotes r) fetchrefstags missing
@@ -140,7 +140,9 @@ retrieveMissingObjects missing referencerepo r
 		ps' = 
 			[ Param "fetch"
 			, Param fetchurl
-			, Params "--force --update-head-ok --quiet"
+			, Param "--force"
+			, Param "--update-head-ok"
+			, Param "--quiet"
 			] ++ ps
 		fetchr' = fetchr { gitGlobalOpts = gitGlobalOpts fetchr ++ nogc }
 		nogc = [ Param "-c", Param "gc.auto=0" ]