Control.Eff.Concurrent.Protocol.StatefulServer

A better, more safe implementation of the Erlang/OTP gen_server behaviour.

Since: 0.24.0

Documentation

class Typeable (Protocol a) => Server (a :: Type) q where

A class for Stateful server processes.

This is inspired by The Elm Architecture, without the view callback.

This can be used for a variety of typical server loop implementations.

Since: 0.24.0

Minimal complete definition

update

Associated Types

data StartArgument a q

The value that defines what is required to initiate a Server loop.

type Protocol a :: Type

The index type of the Events that this server processes. This is the first parameter to the Request and therefore of the Pdu family.

type Model a :: Type

Type of the model data, given to every invocation of update via the ModelState effect. The model of a server loop is changed through incoming Events. It is initially calculated by setup.

type Settings a :: Type

Type of read-only state.

Methods

setup :: StartArgument a q -> Eff (InterruptableProcess q) (Model a, Settings a)

Return an initial Model and Settings

setup :: (Default (Model a), Default (Settings a)) => StartArgument a q -> Eff (InterruptableProcess q) (Model a, Settings a)

Return an initial Model and Settings

update :: StartArgument a q -> Event (Protocol a) -> Eff (ModelState a ': (SettingsReader a ': InterruptableProcess q)) ()

Update the Model based on the Event.

Instances

(TangibleObserver o, TangiblePdu (Observer o) Asynchronous, Lifted IO q, Member Logs q) => Server (ObservationQueue o) q

Defined in Control.Eff.Concurrent.Protocol.Observer.Queue

Associated Types

data StartArgument (ObservationQueue o) q :: Type

type Protocol (ObservationQueue o) :: Type

type Model (ObservationQueue o) :: Type

type Settings (ObservationQueue o) :: Type

Methods

setup :: StartArgument (ObservationQueue o) q -> Eff (InterruptableProcess q) (Model (ObservationQueue o), Settings (ObservationQueue o))

update :: StartArgument (ObservationQueue o) q -> Event (Protocol (ObservationQueue o)) -> Eff (ModelState (ObservationQueue o) ': (SettingsReader (ObservationQueue o) ': InterruptableProcess q)) ()

(Lifted IO q, LogsTo IO q, TangibleSup p, Tangible (ChildId p), Server p q) => Server (Sup p) q

Defined in Control.Eff.Concurrent.Protocol.Supervisor

Associated Types

data StartArgument (Sup p) q :: Type

type Protocol (Sup p) :: Type

type Model (Sup p) :: Type

type Settings (Sup p) :: Type

Methods

setup :: StartArgument (Sup p) q -> Eff (InterruptableProcess q) (Model (Sup p), Settings (Sup p))

update :: StartArgument (Sup p) q -> Event (Protocol (Sup p)) -> Eff (ModelState (Sup p) ': (SettingsReader (Sup p) ': InterruptableProcess q)) ()

start :: forall a q h. (HasCallStack, Typeable a, LogsTo h (InterruptableProcess q), Server (Stateful a) (InterruptableProcess q), Server a q) => StartArgument a q -> Eff (InterruptableProcess q) (Endpoint (Protocol a))

Execute the server loop.

Since: 0.24.0

startLink :: forall a q h. (HasCallStack, Typeable a, LogsTo h (InterruptableProcess q), Server (Stateful a) (InterruptableProcess q), Server a q) => StartArgument a q -> Eff (InterruptableProcess q) (Endpoint (Protocol a))

Execute the server loop.

Since: 0.24.0

type ModelState a = State (Model a)

The Effect type of mutable Model in a Server instance.

Since: 0.24.0

modifyModel :: forall a e. Member (ModelState a) e => (Model a -> Model a) -> Eff e ()

Modify the Model of a Server.

Since: 0.24.0

getAndModifyModel :: forall a e. Member (ModelState a) e => (Model a -> Model a) -> Eff e (Model a)

Modify the Model of a Server and return the old value.

Since: 0.24.0

modifyAndGetModel :: forall a e. Member (ModelState a) e => (Model a -> Model a) -> Eff e (Model a)

Modify the Model of a Server and return the new value.

Since: 0.24.0

getModel :: forall a e. Member (ModelState a) e => Eff e (Model a)

Return the Model of a Server.

Since: 0.24.0

putModel :: forall a e. Member (ModelState a) e => Model a -> Eff e ()

Overwrite the Model of a Server.

Since: 0.24.0

getAndPutModel :: forall a e. Member (ModelState a) e => Model a -> Eff e (Model a)

Overwrite the Model of a Server, return the old value.

Since: 0.24.0

useModel :: forall a b e. Member (ModelState a) e => Getting b (Model a) b -> Eff e b

Return a element selected by a Lens of the Model of a Server.

Since: 0.24.0

zoomModel :: forall a b c e. Member (ModelState a) e => Lens' (Model a) b -> Eff (State b ': e) c -> Eff e c

Run an action that modifies portions of the Model of a Server defined by the given Lens.

Since: 0.24.0

type SettingsReader a = Reader (Settings a)

The Effect type of readonly Settings in a Server instance.

Since: 0.24.0

askSettings :: forall a e. Member (SettingsReader a) e => Eff e (Settings a)

Return the read-only Settings of a Server

Since: 0.24.0

viewSettings :: forall a b e. Member (SettingsReader a) e => Getting b (Settings a) b -> Eff e b

Return the read-only Settings of a Server as viewed through a Lens

Since: 0.24.0

Re-exports

data Event a where

Internal protocol to communicate incoming messages and other events to the instances of Server.

Note that this is required to receive any kind of messages in protocolServerLoop.

Since: 0.24.0

Constructors

OnCall :: forall a r. (Tangible r, TangiblePdu a (Synchronous r)) => Serializer (Reply a r) -> RequestOrigin a r -> Pdu a (Synchronous r) -> Event a

A Synchronous message was received. If an implementation wants to delegate nested Pdus, it can contramap the reply Serializer such that the Reply received by the caller has the correct type.

Since: 0.24.1

OnCast :: forall a. TangiblePdu a Asynchronous => Pdu a Asynchronous -> Event a

OnInterrupt :: Interrupt Recoverable -> Event a

OnDown :: ProcessDown -> Event a

OnTimeOut :: TimerElapsed -> Event a

OnMessage :: StrictDynamic -> Event a

Instances

Show (Event a)

Defined in Control.Eff.Concurrent.Protocol.EffectfulServer

Methods

showsPrec :: Int -> Event a -> ShowS

show :: Event a -> String

showList :: [Event a] -> ShowS

NFData a => NFData (Event a)

Defined in Control.Eff.Concurrent.Protocol.EffectfulServer

Methods

rnf :: Event a -> ()

type ToPretty (Event a :: Type)

Defined in Control.Eff.Concurrent.Protocol.EffectfulServer

type ToPretty (Event a :: Type) = ToPretty a <+> PutStr "event"

data RequestOrigin (proto :: Type) reply

Wraps the source ProcessId and a unique identifier for a Call.

Since: 0.15.0

Constructors

RequestOrigin

Fields

• _requestOriginPid :: !ProcessId
• _requestOriginCallRef :: !Int

Instances

Eq (RequestOrigin proto reply)

Defined in Control.Eff.Concurrent.Protocol.Request

Methods

(==) :: RequestOrigin proto reply -> RequestOrigin proto reply -> Bool

(/=) :: RequestOrigin proto reply -> RequestOrigin proto reply -> Bool

Ord (RequestOrigin proto reply)

Defined in Control.Eff.Concurrent.Protocol.Request

Methods

compare :: RequestOrigin proto reply -> RequestOrigin proto reply -> Ordering

(<) :: RequestOrigin proto reply -> RequestOrigin proto reply -> Bool

(<=) :: RequestOrigin proto reply -> RequestOrigin proto reply -> Bool

(>) :: RequestOrigin proto reply -> RequestOrigin proto reply -> Bool

(>=) :: RequestOrigin proto reply -> RequestOrigin proto reply -> Bool

max :: RequestOrigin proto reply -> RequestOrigin proto reply -> RequestOrigin proto reply

min :: RequestOrigin proto reply -> RequestOrigin proto reply -> RequestOrigin proto reply

Show (RequestOrigin p r)

Defined in Control.Eff.Concurrent.Protocol.Request

Methods

showsPrec :: Int -> RequestOrigin p r -> ShowS

show :: RequestOrigin p r -> String

showList :: [RequestOrigin p r] -> ShowS

Generic (RequestOrigin proto reply)

Defined in Control.Eff.Concurrent.Protocol.Request

Associated Types

type Rep (RequestOrigin proto reply) :: Type -> Type

Methods

from :: RequestOrigin proto reply -> Rep (RequestOrigin proto reply) x

to :: Rep (RequestOrigin proto reply) x -> RequestOrigin proto reply

NFData (RequestOrigin p r)

Defined in Control.Eff.Concurrent.Protocol.Request

Methods

rnf :: RequestOrigin p r -> ()

type Rep (RequestOrigin proto reply)

Defined in Control.Eff.Concurrent.Protocol.Request

type Rep (RequestOrigin proto reply) = D1 (MetaData "RequestOrigin" "Control.Eff.Concurrent.Protocol.Request" "extensible-effects-concurrent-0.24.1-7VbTaDuu8D6CKvnzB0ZvnK" False) (C1 (MetaCons "RequestOrigin" PrefixI True) (S1 (MetaSel (Just "_requestOriginPid") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 ProcessId) :*: S1 (MetaSel (Just "_requestOriginCallRef") NoSourceUnpackedness SourceStrict DecidedStrict) (Rec0 Int)))

data Reply protocol reply where

The wrapper around replies to Calls.

Since: 0.15.0

Constructors

Reply

Fields

• :: Tangible reply
• => { _replyTo :: RequestOrigin protocol reply
•    , _replyValue :: reply
•    } -> Reply protocol reply

Instances

Show r => Show (Reply p r)

Defined in Control.Eff.Concurrent.Protocol.Request

Methods

showsPrec :: Int -> Reply p r -> ShowS

show :: Reply p r -> String

showList :: [Reply p r] -> ShowS

NFData (Reply p r)

Defined in Control.Eff.Concurrent.Protocol.Request

Methods

rnf :: Reply p r -> ()

sendReply :: (SetMember Process (Process q) eff, Member Interrupts eff, Tangible reply, Typeable protocol) => Serializer (Reply protocol reply) -> RequestOrigin protocol reply -> reply -> Eff eff ()

Send a Reply to a Call.

The reply will be deeply evaluated to rnf.

Since: 0.15.0