git-annex/CmdLine/Batch.hs

41 lines
1.1 KiB
Haskell

{- git-annex batch commands
-
- Copyright 2015 Joey Hess <id@joeyh.name>
-
- Licensed under the GNU GPL version 3 or higher.
-}
module CmdLine.Batch where
import Common.Annex
import Command
batchOption :: Option
batchOption = flagOption [] "batch" "enable batch mode"
data BatchMode = Batch | NoBatch
type Batchable t = BatchMode -> t -> CommandStart
-- A Batchable command can run in batch mode, or not.
-- In batch mode, one line at a time is read, parsed, and a reply output to
-- stdout. In non batch mode, the command's parameters are parsed and
-- a reply output for each.
batchable :: ((t -> CommandStart) -> CommandSeek) -> Batchable t -> CommandSeek
batchable seeker starter params = ifM (getOptionFlag batchOption)
( batchloop
, seeker (starter NoBatch) params
)
where
batchloop = do
mp <- liftIO $ catchMaybeIO getLine
case mp of
Nothing -> return ()
Just p -> do
seeker (starter Batch) [p]
batchloop
-- bad input is indicated by an empty line in batch mode. In non batch
-- mode, exit on bad input.
batchBadInput :: BatchMode -> Annex ()
batchBadInput NoBatch = liftIO exitFailure
batchBadInput Batch = liftIO $ putStrLn ""