git-annex/Annex.hs
Joey Hess b471822cfe move supportedBackends list into annex monad
This was necessary so the File backend could import Backend w/o a cycle.

Moved code that checks whether enough backends have a file into File
backend.
2010-10-17 11:47:36 -04:00

83 lines
1.9 KiB
Haskell

{- git-annex monad -}
module Annex (
new,
run,
gitRepo,
gitRepoChange,
backends,
backendsChange,
supportedBackends,
supportedBackendsChange,
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 -> [Backend] -> IO AnnexState
new gitrepo allbackends = do
let s = Backend.AnnexState {
Backend.repo = gitrepo,
Backend.backends = [],
Backend.supportedBackends = allbackends,
Backend.flags = []
}
(_,s') <- Annex.run s (prep gitrepo)
return s'
where
prep gitrepo = do
-- read git config and update state
gitrepo' <- liftIO $ Git.configRead gitrepo
Annex.gitRepoChange gitrepo'
-- 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 ()
supportedBackends :: Annex [Backend]
supportedBackends = do
state <- get
return (Backend.supportedBackends state)
supportedBackendsChange :: [Backend] -> Annex ()
supportedBackendsChange b = do
state <- get
put state { Backend.supportedBackends = 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 ()