query package:acid-state

query :: QueryEvent event => AcidState (EventState event) -> event -> IO (EventResult event)

acid-state Data.Acid Data.Acid.Abstract

Issue a Query event and wait for its result. Events may be issued in parallel.

query :: QueryEvent event => AcidState (EventState event) -> event -> EventResult event

acid-state Data.Acid.Memory.Pure

Issue a Query event and wait for its result.

data Query st a

acid-state Data.Acid Data.Acid.Memory.Pure

Context monad for Query events.

newtype Query st a

acid-state Data.Acid.Common

Context monad for Query events.

Query :: Reader st a -> Query st a

acid-state Data.Acid.Common

query' :: (QueryEvent event, MonadIO m) => AcidState (EventState event) -> event -> m (EventResult event)

acid-state Data.Acid.Abstract Data.Acid.Advanced

Same as query but lifted into any monad capable of doing IO.

queryCold :: AcidState st -> Tagged ByteString -> IO ByteString

acid-state Data.Acid.Abstract

class Method ev => QueryEvent ev

acid-state Data.Acid Data.Acid.Common Data.Acid.Memory.Pure

All QueryEvents are also Methods.

QueryEvent :: QueryEvent ev => (ev -> Query (EventState ev) (EventResult ev)) -> MethodSerialiser ev -> Event (EventState ev)

acid-state Data.Acid.Advanced Data.Acid.Common Data.Acid.Memory.Pure

liftQuery :: Query st a -> Update st a

acid-state Data.Acid Data.Acid.Common Data.Acid.Memory.Pure

Run a query in the Update Monad.

_query :: AcidState st -> forall event . (QueryEvent event, EventState event ~ st) => event -> IO (EventResult event)

acid-state Data.Acid.Abstract

unQuery :: Query st a -> Reader st a

acid-state Data.Acid.Common

runQuery :: Query s r -> s -> r

acid-state Data.Acid.Memory.Pure

Execute the Query monad in a pure environment.