git-annex sim command is working

Had to add Read instances to Key and NumCopies and some other similar
types. I only expect to use those in serializing a sim. Of course, this
risks that implementation changes break reading old data. For a sim,
that would not be a big problem.

Types/Group.hs

@@ -22,7 +22,7 @@ import qualified Data.Set as S
 import qualified Data.ByteString as S
 
 newtype Group = Group S.ByteString
-	deriving (Eq, Ord, Show)
+	deriving (Eq, Ord, Show, Read)
 
 fromGroup :: Group -> String
 fromGroup (Group g) = decodeBS g

Types/Key.hs

@@ -68,7 +68,7 @@ instance NFData KeyData
 data Key = MkKey
 	{ keyData :: KeyData
 	, keySerialization :: S.ShortByteString
-	} deriving (Show, Generic)
+	} deriving (Show, Read, Generic)
 
 instance Eq Key where
 	-- comparing the serialization would be unnecessary work

Types/NumCopies.hs

@@ -44,7 +44,7 @@ import Control.Monad.IO.Class (MonadIO)
 import Data.Time.Clock.POSIX (POSIXTime)
 
 newtype NumCopies = NumCopies Int
-	deriving (Ord, Eq, Show)
+	deriving (Ord, Eq, Show, Read)
 
 -- Smart constructor; prevent configuring numcopies to 0 which would
 -- cause data loss.
@@ -57,7 +57,7 @@ fromNumCopies :: NumCopies -> Int
 fromNumCopies (NumCopies n) = n
 
 newtype MinCopies = MinCopies Int
-	deriving (Ord, Eq, Show)
+	deriving (Ord, Eq, Show, Read)
 
 configuredMinCopies :: Int -> MinCopies
 configuredMinCopies n

Types/RepoSize.hs

@@ -26,7 +26,7 @@ newtype RepoSize = RepoSize { fromRepoSize :: Integer }
 
 -- The maximum size of a repo.
 newtype MaxSize = MaxSize { fromMaxSize :: Integer }
-	deriving (Show, Eq, Ord)
+	deriving (Show, Read, Eq, Ord)
 
 -- An offset to the size of a repo.
 newtype SizeOffset = SizeOffset { fromSizeChange :: Integer }

Types/TrustLevel.hs

@@ -22,7 +22,7 @@ import Data.Ord
 import Types.UUID
 
 data TrustLevel = DeadTrusted | UnTrusted | SemiTrusted | Trusted
-	deriving (Eq, Enum, Ord, Bounded, Show)
+	deriving (Eq, Enum, Ord, Bounded, Show, Read)
 
 instance Default TrustLevel  where
 	def = SemiTrusted