golfing

LocationLog.hs

@@ -23,7 +23,6 @@ module LocationLog (
 ) where
 
 import System.FilePath
-import Control.Monad (when)
 import Control.Applicative
 import Data.Maybe
 
@@ -36,16 +35,16 @@ import PresenceLog
 
 {- Log a change in the presence of a key's value in a repository. -}
 logChange :: Git.Repo -> Key -> UUID -> LogStatus -> Annex ()
-logChange repo key u s = do
-	when (null u) $
-		error $ "unknown UUID for " ++ Git.repoDescribe repo ++ 
-			" (have you run git annex init there?)"
-	addLog (logFile key) =<< logNow s u
+logChange repo key u s
+	| null u = error $
+		"unknown UUID for " ++ Git.repoDescribe repo ++ 
+		" (have you run git annex init there?)"
+	| otherwise = addLog (logFile key) =<< logNow s u
 
 {- Returns a list of repository UUIDs that, according to the log, have
  - the value of a key. -}
 keyLocations :: Key -> Annex [UUID]
-keyLocations key = currentLog $ logFile key
+keyLocations = currentLog . logFile
 
 {- Finds all keys that have location log information.
  - (There may be duplicate keys in the list.) -}

PresenceLog.hs

@@ -85,7 +85,7 @@ readLog :: FilePath -> Annex [LogLine]
 readLog file = parseLog <$> Branch.get file
 
 parseLog :: String -> [LogLine]
-parseLog s = filter parsable $ map read $ lines s
+parseLog = filter parsable . map read . lines
 	where
 		-- some lines may be unparseable, avoid them
 		parsable l = status l /= Undefined
@@ -102,23 +102,18 @@ logNow s i = do
 
 {- Reads a log and returns only the info that is still in effect. -}
 currentLog :: FilePath -> Annex [String]
-currentLog file = do
-	ls <- readLog file
-	return $ map info $ filterPresent ls
+currentLog file = map info . filterPresent <$> readLog file
 
 {- Returns the info from LogLines that are in effect. -}
 filterPresent :: [LogLine] -> [LogLine]
-filterPresent ls = filter (\l -> InfoPresent == status l) $ compactLog ls
-
-type LogMap = Map.Map String LogLine
+filterPresent = filter (\l -> InfoPresent == status l) . compactLog
 
 {- Compacts a set of logs, returning a subset that contains the current
  - status. -}
 compactLog :: [LogLine] -> [LogLine]
-compactLog = compactLog' Map.empty
-compactLog' :: LogMap -> [LogLine] -> [LogLine]
-compactLog' m [] = Map.elems m
-compactLog' m (l:ls) = compactLog' (mapLog m l) ls
+compactLog = Map.elems . foldl mapLog Map.empty
+
+type LogMap = Map.Map String LogLine
 
 {- Inserts a log into a map of logs, if the log has better (ie, newer)
  - information than the other logs in the map -}
@@ -128,5 +123,6 @@ mapLog m l =
 		then Map.insert i l m
 		else m
 	where
-		better = maybe True (\l' -> date l' <= date l) $ Map.lookup i m
+		better = maybe True newer $ Map.lookup i m
+		newer l' = date l' <= date l
 		i = info l