simplified a bunch of Maybe handling

Command/DropUnused.hs

@@ -58,14 +58,13 @@ start (unused, unusedbad, unusedtmp) s = notBareRepo $ search
 					next $ a key
 
 perform :: Key -> CommandPerform
-perform key = do
-	from <- Annex.getState Annex.fromremote
-	case from of
-		Just name -> do
+perform key = maybe droplocal dropremote =<< Annex.getState Annex.fromremote
+	where
+		dropremote name = do
 			r <- Remote.byName name
 			showNote $ "from " ++ Remote.name r ++ "..."
 			next $ Command.Move.fromCleanup r True key
-		_ -> do
+		droplocal = do
 			backend <- keyBackend key
 			Command.Drop.perform key backend (Just 0) -- force drop
 

Command/InitRemote.hs

@@ -68,11 +68,11 @@ cleanup u c = do
 findByName :: String -> Annex (UUID, RemoteClass.RemoteConfig)
 findByName name = do
 	m <- Remote.readRemoteLog
-	case findByName' name m of
-		Just i -> return i
-		Nothing -> do
+	maybe generate return $ findByName' name m
+	where
+		generate = do
 			uuid <- liftIO $ genUUID
-			return $ (uuid, M.insert nameKey name M.empty)
+			return (uuid, M.insert nameKey name M.empty)
 
 findByName' :: String ->  M.Map UUID RemoteClass.RemoteConfig -> Maybe (UUID, RemoteClass.RemoteConfig)
 findByName' n m = if null matches then Nothing else Just $ head matches
@@ -86,12 +86,13 @@ findByName' n m = if null matches then Nothing else Just $ head matches
 
 {- find the specified remote type -}
 findType :: RemoteClass.RemoteConfig -> Annex (RemoteClass.RemoteType Annex)
-findType config = 
-	case M.lookup typeKey config of
-		Nothing -> error "Specify the type of remote with type="
-		Just s -> case filter (\i -> RemoteClass.typename i == s) Remote.remoteTypes of
+findType config = maybe unspecified specified $ M.lookup typeKey config
+	where
+		unspecified = error "Specify the type of remote with type="
+		specified s = case filter (findtype s) Remote.remoteTypes of
 			[] -> error $ "Unknown remote type " ++ s
 			(t:_) -> return t
+		findtype s i = RemoteClass.typename i == s
 
 {- The name of a configured remote is stored in its config using this key. -}
 nameKey :: String

Command/Map.hs

@@ -84,10 +84,7 @@ repoName umap r
 	| otherwise = M.findWithDefault fallback repouuid umap
 	where
 		repouuid = getUncachedUUID r
-		fallback =
-			case (Git.repoRemoteName r) of
-				Just n -> n
-				Nothing -> "unknown"
+		fallback = maybe "unknown" id $ Git.repoRemoteName r
 
 {- A unique id for the node for a repo. Uses the annex.uuid if available. -}
 nodeId :: Git.Repo -> String
@@ -121,13 +118,10 @@ edge umap fullinfo from to =
 		{- Only name an edge if the name is different than the name
 		 - that will be used for the destination node, and is
 		 - different from its hostname. (This reduces visual clutter.) -}
-		edgename =
-			case (Git.repoRemoteName to) of
-				Nothing -> Nothing
-				Just n ->
-					if (n == repoName umap fullto || n == hostname fullto)
-						then Nothing
-						else Just n
+		edgename = maybe Nothing calcname $ Git.repoRemoteName to
+		calcname n
+			| n == repoName umap fullto || n == hostname fullto = Nothing
+			| otherwise = Just n
 
 unreachable :: String -> String
 unreachable = Dot.fillColor "red"

Command/Unused.hs

@@ -41,12 +41,7 @@ start = notBareRepo $ do
 
 perform :: CommandPerform
 perform = do
-	from <- Annex.getState Annex.fromremote
-	case from of
-		Just name -> do
-			r <- Remote.byName name
-			checkRemoteUnused r
-		_ -> checkUnused
+	maybe checkUnused checkRemoteUnused =<< Annex.getState Annex.fromremote
 	next $ return True
 
 checkUnused :: Annex ()
@@ -63,8 +58,11 @@ checkUnused = do
 			writeUnusedFile file unusedlist
 			return $ length l
 
-checkRemoteUnused :: Remote.Remote Annex -> Annex ()
-checkRemoteUnused r = do
+checkRemoteUnused :: String -> Annex ()
+checkRemoteUnused name = checkRemoteUnused' =<< Remote.byName name
+
+checkRemoteUnused' :: Remote.Remote Annex -> Annex ()
+checkRemoteUnused' r = do
 	g <- Annex.gitRepo
 	showNote $ "checking for unused data on " ++ Remote.name r ++ "..."
 	referenced <- getKeysReferenced