first pass at using new keys

It compiles. It sorta works. Several subcommands are FIXME marked and
broken, because things that used to accept separate --backend and --key
params need to be changed to accept just a --key that encodes all the key
info, now that there is metadata in keys.

Key.hs

@@ -5,20 +5,35 @@
  - Licensed under the GNU GPL version 3 or higher.
  -}
 
-module Key where
+module Key (
+	Key(..),
+	stubKey,
+	readKey,
+
+	prop_idempotent_key_read_show
+) where
 
 import Test.QuickCheck
 import Utility
+import System.Posix.Types
 
-{- A Key has a unique name, is associated with a backend,
- - and may contain other metadata. -}
+{- A Key has a unique name, is associated with a key/value backend,
+ - and may contain other optional metadata. -}
 data Key = Key {
 	keyName :: String,
-	keyBackend :: String,
-	keySize :: Maybe Int,
-	keyMtime :: Maybe Int
+	keyBackendName :: String,
+	keySize :: Maybe Integer,
+	keyMtime :: Maybe EpochTime
 } deriving (Eq, Ord)
 
+stubKey :: Key
+stubKey = Key {
+	keyName = "",
+	keyBackendName = "",
+	keySize = Nothing,
+	keyMtime = Nothing
+}
+
 fieldSep :: Char
 fieldSep = ','
 
@@ -26,7 +41,7 @@ fieldSep = ','
  - The name field is always shown last, and is the only field
  - allowed to contain the fieldSep. -}
 instance Show Key where
-	show Key { keyBackend = b, keySize = s, keyMtime = m, keyName = n } =
+	show Key { keyBackendName = b, keySize = s, keyMtime = m, keyName = n } =
 		('b' : b) +++ ('s' ?: s) +++ ('m' ?: m) +++ ('n' : n)
 		where
 			"" +++ y = y
@@ -36,16 +51,9 @@ instance Show Key where
 			_ ?: _ = ""
 
 readKey :: String -> Maybe Key
-readKey s = if key == stub then Nothing else key
+readKey s = if key == Just stubKey then Nothing else key
 	where
-		key = findfields s stub
-
-		stub = Just Key {
-			keyName = "",
-			keyBackend = "",
-			keySize = Nothing,
-			keyMtime = Nothing
-		}
+		key = findfields s $ Just stubKey
 
 		findfields ('n':v) (Just k) = Just $ k { keyName = v }
 		findfields (c:v) (Just k) =
@@ -54,7 +62,7 @@ readKey s = if key == stub then Nothing else key
 				_ -> Nothing
 		findfields _ v = v
 		
-		addfield k 'b' v = Just k { keyBackend = v }
+		addfield k 'b' v = Just k { keyBackendName = v }
 		addfield k 's' v = Just k { keySize = readMaybe v }
 		addfield k 'm' v = Just k { keyMtime = readMaybe v }
 		addfield _ _ _ = Nothing
@@ -65,8 +73,7 @@ instance Arbitrary Key where
 		n <- arbitrary
 		b <- elements ['A'..'Z']
 		s <- arbitrary
-		m <- arbitrary
-		return $ Key { keyName = n, keyBackend = [b] , keySize = s, keyMtime = m }
+		return $ Key { keyName = n, keyBackendName = [b] , keySize = s }
 
 prop_idempotent_key_read_show :: Key -> Bool
 prop_idempotent_key_read_show k = Just k == (readKey $ show k)