git-annex/Annex.hs
2010-10-14 23:52:45 -04:00

70 lines
1.5 KiB
Haskell

{- git-annex monad -}
module Annex (
new,
run,
gitRepo,
gitRepoChange,
backends,
backendsChange,
flagIsSet,
flagChange,
Flag(..)
) where
import Control.Monad.State
import qualified GitRepo as Git
import Types
import qualified BackendTypes as Backend
{- Create and returns an Annex state object for the specified git repo.
-}
new :: Git.Repo -> IO AnnexState
new g = do
let s = Backend.AnnexState {
Backend.repo = g,
Backend.backends = [],
Backend.flags = []
}
(_,s') <- Annex.run s (prep g)
return s'
where
prep g = do
-- read git config and update state
g' <- liftIO $ Git.configRead g
Annex.gitRepoChange g'
-- performs an action in the Annex monad
run state action = runStateT (action) state
-- Annex monad state accessors
gitRepo :: Annex Git.Repo
gitRepo = do
state <- get
return (Backend.repo state)
gitRepoChange :: Git.Repo -> Annex ()
gitRepoChange r = do
state <- get
put state { Backend.repo = r }
return ()
backends :: Annex [Backend]
backends = do
state <- get
return (Backend.backends state)
backendsChange :: [Backend] -> Annex ()
backendsChange b = do
state <- get
put state { Backend.backends = b }
return ()
flagIsSet :: Flag -> Annex Bool
flagIsSet flag = do
state <- get
return $ elem flag $ Backend.flags state
flagChange :: Flag -> Bool -> Annex ()
flagChange flag set = do
state <- get
let f = filter (/= flag) $ Backend.flags state
if (set)
then put state { Backend.flags = (flag:f) }
else put state { Backend.flags = f }
return ()