happstack-state-0.5.0.4: Event-based distributed state.

Happstack.State.ComponentSystem

Synopsis

Documentation

data End Source

Equivalent of [] for type level lists. Used for Components that have no dependencies

Constructors

End 

Instances

SubHandlers End

In correspondence with its role as [] in the type level list, the instance for End does not add any components to the set.

data h :+: t Source

Type level Cons for enumerating type dependencies of a Component

Constructors

h :+: t 

Instances

(Methods a, Component a, SubHandlers b) => SubHandlers (:+: a b)

This is the instance that completes the definition of :+: and End as being the constructors of a type level list in SubHandlers. Note that since b needs to be an instance of SubHandlers, the list needs to be terminated with End.

class (Serialize ev, Serialize res) => UpdateEvent ev res | ev -> resSource

data Method st whereSource

Method is the actual type that all Updates and Querys eventually get lifted into via mkMethods.

Constructors

Update :: UpdateEvent ev res => (ev -> Update st res) -> Method st 
Query :: QueryEvent ev res => (ev -> Query st res) -> Method st 

Instances

Show (Method st) 

methodType :: Method t -> StringSource

Displays the type of a Method

class Methods a whereSource

Class for enumerating the set of defined methods by the type of the state. Instances should not be defined directly, but using mkMethods

Methods

methods :: Proxy a -> [Method a]Source

data MethodMap whereSource

Constructors

MethodMap :: Component st => Map String (Method st) -> MethodMap 

Instances

type ComponentTree = Map String MethodMapSource

State type -> method map

type ComponentVersions = Map String [ByteString]Source

State type -> all versions

class (SubHandlers (Dependencies a), Serialize a) => Component a whereSource

In order to be used as a part of Happstack's MACID state, a data type needs to be an instance of Component. The minimal definition is an initialValue and the type corresponding to the set of Dependencies. Note that the SubHandlers condition will be automatically met if the Dependencies is built from End and :+: with other instances of Component and Methods

Associated Types

type Dependencies a Source

class SubHandlers a whereSource

SubHandlers is used to build up the set of components corresponding to the instance type.

Instances

SubHandlers End

In correspondence with its role as [] in the type level list, the instance for End does not add any components to the set.

(Methods a, Component a, SubHandlers b) => SubHandlers (:+: a b)

This is the instance that completes the definition of :+: and End as being the constructors of a type level list in SubHandlers. Note that since b needs to be an instance of SubHandlers, the list needs to be terminated with End.

dup :: String -> bSource

An error is thrown when this is evaluated.