git-annex/git-annex.hs
2010-10-25 19:17:11 -04:00

48 lines
1.4 KiB
Haskell

{- git-annex main program -}
import IO (try)
import System.IO
import System.Environment
import qualified Annex
import Types
import Core
import Commands
import qualified GitRepo as Git
import BackendList
main = do
args <- getArgs
gitrepo <- Git.repoFromCwd
state <- Annex.new gitrepo allBackends
(configure, actions) <- parseCmd args state
tryRun state $ [startup] ++ configure ++ actions ++ [shutdown]
{- Runs a list of Annex actions. Catches IO errors and continues
- (but explicitly thrown errors terminate the whole command).
- Propigates an overall error status at the end.
-
- This runs in the IO monad, not in the Annex monad. It seems that
- exceptions can only be caught in the IO monad, not in a stacked monad;
- or more likely I missed an easy way to do it. So, I have to laboriously
- thread AnnexState through this function.
-}
tryRun :: AnnexState -> [Annex Bool] -> IO ()
tryRun state actions = tryRun' state 0 actions
tryRun' state errnum (a:as) = do
result <- try $ Annex.run state a
case (result) of
Left err -> do
showErr err
tryRun' state (errnum + 1) as
Right (True,state') -> tryRun' state' errnum as
Right (False,state') -> tryRun' state' (errnum + 1) as
tryRun' state errnum [] = do
if (errnum > 0)
then error $ (show errnum) ++ " failed"
else return ()
{- Exception pretty-printing. -}
showErr e = do
hPutStrLn stderr $ "git-annex: " ++ (show e)
return ()