more command-specific options

Made --from and --to command-specific options.

Added generic storage for values of command-specific options,
which allows removing some of the special case fields in AnnexState.

(Also added generic storage for command-specific flags, although there are
not yet any.)

Note that this storage uses a Map, so repeatedly looking up the same value
is slightly more expensive than looking up an AnnexState field. But, the
value can be looked up once in the seek stage, transformed as necessary,
and passed in a closure to the start stage, and this avoids that overhead.

Still, I'm hesitant to use this for things like force or fast flags.
It's probably best to reserve it for flags that are only used by a few
commands, or options like --from and --to that it's important only be
allowed to be used with commands that implement them, to avoid user
confusion.

1 files changed, 12 insertions, 7 deletions

diff --git a/Command/Find.hs b/Command/Find.hs
index c86db5fa6..eb0267c14 100644
--- a/Command/Find.hs
+++ b/Command/Find.hs
@@ -23,20 +23,25 @@ def = [withOptions [formatOption, print0Option] $
 	command "find" paramPaths seek "lists available files"]
 
 print0Option :: Option
-print0Option = Option [] ["print0"] (NoArg $ setFormat "${file}\0")
+print0Option = Option [] ["print0"] (NoArg $ Annex.setField "format" "${file}\0")
 	"terminate output with null"
 
+formatOption :: Option
+formatOption = fieldOption [] "format" paramFormat "control format of output"
+
 seek :: [CommandSeek]
-seek = [withFilesInGit $ whenAnnexed start]
+seek = [withField "format" formatconverter $ \f ->
+		withFilesInGit $ whenAnnexed $ start f]
+	where
+		formatconverter = maybe Nothing (Just . Utility.Format.gen)
 
-start :: FilePath -> (Key, Backend) -> CommandStart
-start file (key, _) = do
+start :: Maybe Utility.Format.Format -> FilePath -> (Key, Backend) -> CommandStart
+start format file (key, _) = do
 	-- only files inAnnex are shown, unless the user has requested
 	-- others via a limit
 	whenM (liftM2 (||) limited (inAnnex key)) $
-		unlessM (showFullJSON vars) $ do
-			f <- Annex.getState Annex.format
-			case f of
+		unlessM (showFullJSON vars) $
+			case format of
 				Nothing -> liftIO $ putStrLn file
 				Just formatter -> liftIO $ putStr $
 					Utility.Format.format formatter $