happstack-state-0.4.1: Event-based distributed state. Source code Contents Index

Happstack.State.ComponentSystem

Synopsis

data End = End data h :+: t = h :+: t class (Serialize ev, Serialize res) => UpdateEvent ev res | ev -> res class (Serialize ev, Serialize res) => QueryEvent ev res | ev -> res data Method st where Update :: UpdateEvent ev res => (ev -> Update st res) -> Method st Query :: QueryEvent ev res => (ev -> Query st res) -> Method st methodType :: Method t -> String class Methods a where methods :: Proxy a -> [Method a] data MethodMap where MethodMap :: Component st => Map String (Method st) -> MethodMap type ComponentTree = Map String MethodMap type ComponentVersions = Map String [ByteString] class (SubHandlers (Dependencies a), Serialize a) => Component a where type Dependencies a initialValue :: a onLoad :: Proxy a -> IO () class SubHandlers a where subHandlers :: a -> Collect () data Collection = Collection ComponentTree ComponentVersions [IO ()] addItem :: MonadState Collection m => String -> MethodMap -> [ByteString] -> IO () -> m () type Collect = State Collection collectHandlers :: (Methods a, Component a) => Proxy a -> (ComponentTree, ComponentVersions, [IO ()]) collectHandlers' :: (Methods a, Component a) => Proxy a -> Collect () dup :: String -> b

Documentation

data End Source

Equivalent of [] for type level lists. Used for Components that have no dependencies Constructors End Instances SubHandlers End

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)

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

Instances UpdateEvent SetCheckpointState () Typeable st => UpdateEvent (SetNewState st) ()

class (Serialize ev, Serialize res) => QueryEvent ev res | ev -> res Source

Instances QueryEvent GetCheckpointState ByteString Typeable st => QueryEvent (GetState st) ByteString

data Method st where Source

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 -> String Source

Displays the type of a Method

class Methods a where Source

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 where Source

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

type ComponentTree = Map String MethodMap Source

State type -> method map

type ComponentVersions = Map String [ByteString] Source

State type -> all versions

class (SubHandlers (Dependencies a), Serialize a) => Component a where Source

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 Methods initialValue :: a Source onLoad :: Proxy a -> IO () Source

class SubHandlers a where Source

SubHandlers is used to build up the set of components corresponding to the instance type. Methods subHandlers :: a -> Collect () Source Instances SubHandlers End (Methods a, Component a, SubHandlers b) => SubHandlers (:+: a b)

data Collection Source

Constructors Collection ComponentTree ComponentVersions [IO ()]

addItem :: MonadState Collection m => String -> MethodMap -> [ByteString] -> IO () -> m () Source

type Collect = State Collection Source

collectHandlers :: (Methods a, Component a) => Proxy a -> (ComponentTree, ComponentVersions, [IO ()]) Source

collectHandlers' :: (Methods a, Component a) => Proxy a -> Collect () Source

dup :: String -> b Source

An error is thrown when this is evaluated.

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