-getRealShare :: MTaskDevice BCShare -> Shared BCValue
-getRealShare dev {sdsi} = SDSSource {SDSSource
- | name = "mTaskShareMap-" +++ toString sdsi, read=rr, write=ww}
- where
- rr name iworld = case read deviceStore iworld of
- (Error e, iworld) = (Error e, iworld)
- (Ok devices, iworld) = case find ((==)dev) devices of
- Nothing = (Error $ exception "Device doesn't exist anymore", iworld)
- Just {deviceShares} = case find (\s->s.identifier == sdsi) deviceShares of
- Nothing = (Error $ exception "Share doesn't exist", iworld)
- Just share = (Ok share.MTaskShare.value, iworld)
-
- // Also send messages
- ww name value iworld = undef//case modify (modFun name value) sdsStore of
-// (Error e, iworld) = (Error e, iworld)
-// (Ok shares, iworld) = (Ok $ const True, iworld)
+instance == MTaskShare where
+ (==) a b = a.identifier == b.identifier
+
+getRealShare :: MTaskDevice MTaskShare -> Shared BCValue
+getRealShare dev share = sdsFocus ()
+ $ mapReadWriteError (deviceLens dev share)
+ $ sdsFocus (Just (dev, share.identifier))
+ $ deviceStore
+
+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
+
+ mwrite :: BCValue [MTaskDevice] -> MaybeError TaskException (Maybe [MTaskDevice])
+ mwrite val devs = case partition ((==)dev) devs of
+ ([], _) = Error $ exception "Device doesn't exist anymore"
+ ([_,_:_], _) = Error $ exception "Multiple matching devices"
+ ([d=:{deviceShares}], devs) = case partition ((==)share) deviceShares of
+ ([], _) = Error $ exception "Share doesn't exist anymore"
+ ([_,_:_], _) = Error $ exception "Multiple matching shares"
+ ([s], shares)
+ # s = {MTaskShare | s & value=val}
+ # d = {MTaskDevice | d & deviceShares=[s:shares]}
+ = Ok $ Just [d:devs]
+
+updateShareFromPublish :: MTaskDevice Int BCValue -> Task BCValue
+updateShareFromPublish dev ident val = set val
+ $ mapReadWriteError (deviceLens dev dummy)
+ $ deviceStoreNP
+where
+ dummy = {MTaskShare|value=BCValue 0,identifier=ident,withTask=[]}