import iTasks
import mTask
import Data.List
+import Data.Error
import Data.Tuple
+from Control.Monad import `b`
from Data.Func import $
from StdFunc import flip
deviceLens dev share = (mread, mwrite)
where
mread :: [MTaskDevice] -> MaybeError TaskException BCValue
- mread devs = case find ((==)dev) devs of
- Nothing = Error $ exception "Device doesn't exist anymore"
- Just {deviceShares} = case find ((==)share) deviceShares of
- Nothing = Error $ exception "Share doesn't exist anymore"
- Just share = Ok share.MTaskShare.value
+ mread devs = mb2error (exception "Device lost") (find ((==)dev) devs)
+ `b` \d->mb2error (exception "Share lost") (find ((==)share) d.deviceShares)
+ `b` \s->Ok s.MTaskShare.value
mwrite :: BCValue [MTaskDevice] -> MaybeError TaskException (Maybe [MTaskDevice])
mwrite val devs = case partition ((==)dev) devs of