Copyright	(c) Max Amanshauser 2016
License	MIT
Maintainer	max@lambdalifting.org
Safe Haskell	None
Language	Haskell2010

Mealstrom.FSM

Description

These defintions are concerned with the basic functions of finite state machines, keeping a memory and state transitions.

Synopsis

type MachineTransformer s e a = Machine s e a -> IO (Machine s e a)
data MealyStatus
- = MealyError
- | Pending
- | Done
class (Hashable k, Eq k) => FSMKey k where
- toText :: k -> Text
- fromText :: Text -> k
class FSMKey k => MealyInstance k s e a
data Change s e a
- = Step UTCTime s e s [a]
- | Count Int
data Instance k s e a = Instance {
- key :: k
- machine :: Machine s e a
}
data Machine s e a = Machine {
- inbox :: [Msg e]
- outbox :: [Msg a]
- committed :: [UUID]
- initState :: s
- currState :: s
- hist :: [Change s e a]
}
mkEmptyMachine :: s -> Machine s e a
mkEmptyInstance :: k -> s -> Instance k s e a
mkInstance :: k -> s -> [Msg e] -> Instance k s e a
data Msg e = Msg {
- msgID :: Maybe UUID
- msgContents :: e
}
mkMsg :: t -> IO (Msg t)
mkMsgs :: [t] -> IO [Msg t]
mkBogusMsg :: Eq t => t -> Msg t
histAppend :: (Eq s, Eq e) => Change s e a -> [Change s e a] -> [Change s e a]

Documentation

type MachineTransformer s e a = Machine s e a -> IO (Machine s e a) Source #

data MealyStatus Source #

A data type that often comes in handy when describing whether updates have succeeded in the backend.

Constructors

MealyError
Pending
Done

Instances

Eq MealyStatus Source #
Instance details Defined in Mealstrom.FSM Methods (==) :: MealyStatus -> MealyStatus -> Bool # (/=) :: MealyStatus -> MealyStatus -> Bool #
Show MealyStatus Source #
Instance details Defined in Mealstrom.FSM Methods showsPrec :: Int -> MealyStatus -> ShowS # show :: MealyStatus -> String # showList :: [MealyStatus] -> ShowS #

class (Hashable k, Eq k) => FSMKey k where Source #

FSMs are uniquely identified by a type k, which must be convertible from/to Text.

Methods

toText :: k -> Text Source #

fromText :: Text -> k Source #

Instances

FSMKey Text Source #
Instance details Defined in Mealstrom.FSM Methods toText :: Text -> Text Source # fromText :: Text -> Text Source #
FSMKey UUID Source #
Instance details Defined in Mealstrom.FSM Methods toText :: UUID -> Text Source # fromText :: Text -> UUID Source #

class FSMKey k => MealyInstance k s e a Source #

This typeclass is needed to provide a constraint for the FSMStore abstraction.

data Change s e a Source #

A change in a FSM is either a (Step Timestamp oldState event newState Actions) or an increase in a counter.

Constructors

Step UTCTime s e s [a]
Count Int

Instances

(Eq s, Eq e) => Eq (Change s e a) Source #	Steps are equal to each other when they originated in the same state received the same event and ended up in the same state
Instance details Defined in Mealstrom.FSM Methods (==) :: Change s e a -> Change s e a -> Bool # (/=) :: Change s e a -> Change s e a -> Bool #
(Show s, Show e, Show a) => Show (Change s e a) Source #
Instance details Defined in Mealstrom.FSM Methods showsPrec :: Int -> Change s e a -> ShowS # show :: Change s e a -> String # showList :: [Change s e a] -> ShowS #
(ToJSON s, ToJSON e, ToJSON a) => ToJSON (Change s e a) Source #
Instance details Defined in Mealstrom.FSM Methods toJSON :: Change s e a -> Value # toEncoding :: Change s e a -> Encoding # toJSONList :: [Change s e a] -> Value # toEncodingList :: [Change s e a] -> Encoding #
(FromJSON s, FromJSON e, FromJSON a) => FromJSON (Change s e a) Source #
Instance details Defined in Mealstrom.FSM Methods parseJSON :: Value -> Parser (Change s e a) # parseJSONList :: Value -> Parser [Change s e a] #

data Instance k s e a Source #

Constructors

Instance
Fields key :: k machine :: Machine s e a

Instances

(Eq k, Eq e, Eq a, Eq s) => Eq (Instance k s e a) Source #
Instance details Defined in Mealstrom.FSM Methods (==) :: Instance k s e a -> Instance k s e a -> Bool # (/=) :: Instance k s e a -> Instance k s e a -> Bool #
(Show k, Show e, Show a, Show s) => Show (Instance k s e a) Source #
Instance details Defined in Mealstrom.FSM Methods showsPrec :: Int -> Instance k s e a -> ShowS # show :: Instance k s e a -> String # showList :: [Instance k s e a] -> ShowS #
Generic (Instance k s e a) Source #
Instance details Defined in Mealstrom.FSM Associated Types type Rep (Instance k s e a) :: Type -> Type # Methods from :: Instance k s e a -> Rep (Instance k s e a) x # to :: Rep (Instance k s e a) x -> Instance k s e a #
(Typeable s, Typeable e, Typeable a, FromJSON s, FromJSON e, FromJSON a, FSMKey k) => FromRow (Instance k s e a) Source #
Instance details Defined in Mealstrom.PostgresJSONStore Methods fromRow :: RowParser (Instance k s e a) #
type Rep (Instance k s e a) Source #
Instance details Defined in Mealstrom.FSM type Rep (Instance k s e a) = D1 (MetaData "Instance" "Mealstrom.FSM" "mealstrom-0.0.1.0-1iE9qiPdHB2KeFDL81oqg9" False) (C1 (MetaCons "Instance" PrefixI True) (S1 (MetaSel (Just "key") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 k) :*: S1 (MetaSel (Just "machine") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Machine s e a))))

data Machine s e a Source #

Constructors

Machine
Fields inbox :: [Msg e] outbox :: [Msg a] committed :: [UUID] initState :: s currState :: s hist :: [Change s e a]

Instances

(Eq e, Eq a, Eq s) => Eq (Machine s e a) Source #
Instance details Defined in Mealstrom.FSM Methods (==) :: Machine s e a -> Machine s e a -> Bool # (/=) :: Machine s e a -> Machine s e a -> Bool #
(Show e, Show a, Show s) => Show (Machine s e a) Source #
Instance details Defined in Mealstrom.FSM Methods showsPrec :: Int -> Machine s e a -> ShowS # show :: Machine s e a -> String # showList :: [Machine s e a] -> ShowS #
Generic (Machine s e a) Source #
Instance details Defined in Mealstrom.FSM Associated Types type Rep (Machine s e a) :: Type -> Type # Methods from :: Machine s e a -> Rep (Machine s e a) x # to :: Rep (Machine s e a) x -> Machine s e a #
(ToJSON s, ToJSON e, ToJSON a) => ToJSON (Machine s e a) Source #	Instance to convert one DB row to an instance of Instance ;) users of this module must provide instances for ToJSON, FromJSON for `s`, `e` and `a`.
Instance details Defined in Mealstrom.PostgresJSONStore Methods toJSON :: Machine s e a -> Value # toEncoding :: Machine s e a -> Encoding # toJSONList :: [Machine s e a] -> Value # toEncodingList :: [Machine s e a] -> Encoding #
(FromJSON s, FromJSON e, FromJSON a) => FromJSON (Machine s e a) Source #
Instance details Defined in Mealstrom.PostgresJSONStore Methods parseJSON :: Value -> Parser (Machine s e a) # parseJSONList :: Value -> Parser [Machine s e a] #
(Typeable s, Typeable e, Typeable a, FromJSON s, FromJSON e, FromJSON a) => FromField (Machine s e a) Source #
Instance details Defined in Mealstrom.PostgresJSONStore Methods fromField :: FieldParser (Machine s e a) #
(Typeable s, Typeable e, Typeable a, ToJSON s, ToJSON e, ToJSON a) => ToField (Machine s e a) Source #
Instance details Defined in Mealstrom.PostgresJSONStore Methods toField :: Machine s e a -> Action #
type Rep (Machine s e a) Source #
Instance details Defined in Mealstrom.FSM type Rep (Machine s e a) = D1 (MetaData "Machine" "Mealstrom.FSM" "mealstrom-0.0.1.0-1iE9qiPdHB2KeFDL81oqg9" False) (C1 (MetaCons "Machine" PrefixI True) ((S1 (MetaSel (Just "inbox") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Msg e]) :: (S1 (MetaSel (Just "outbox") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Msg a]) :: S1 (MetaSel (Just "committed") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [UUID]))) :: (S1 (MetaSel (Just "initState") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 s) :: (S1 (MetaSel (Just "currState") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 s) :*: S1 (MetaSel (Just "hist") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 [Change s e a])))))

mkEmptyMachine :: s -> Machine s e a Source #

mkEmptyInstance :: k -> s -> Instance k s e a Source #

mkInstance :: k -> s -> [Msg e] -> Instance k s e a Source #

data Msg e Source #

Type of messages that are sent between FSMs Messages are always identified by UUID. The purpose of Msg is to attach a unique ID to an event, so that certain guarantees can be provided.

Constructors

Msg
Fields msgID :: Maybe UUID msgContents :: e

Instances

Eq e => Eq (Msg e) Source #
Instance details Defined in Mealstrom.FSM Methods (==) :: Msg e -> Msg e -> Bool # (/=) :: Msg e -> Msg e -> Bool #
Show e => Show (Msg e) Source #
Instance details Defined in Mealstrom.FSM Methods showsPrec :: Int -> Msg e -> ShowS # show :: Msg e -> String # showList :: [Msg e] -> ShowS #
Generic (Msg e) Source #
Instance details Defined in Mealstrom.FSM Associated Types type Rep (Msg e) :: Type -> Type # Methods from :: Msg e -> Rep (Msg e) x # to :: Rep (Msg e) x -> Msg e #
ToJSON e => ToJSON (Msg e) Source #
Instance details Defined in Mealstrom.PostgresJSONStore Methods toJSON :: Msg e -> Value # toEncoding :: Msg e -> Encoding # toJSONList :: [Msg e] -> Value # toEncodingList :: [Msg e] -> Encoding #
FromJSON e => FromJSON (Msg e) Source #
Instance details Defined in Mealstrom.PostgresJSONStore Methods parseJSON :: Value -> Parser (Msg e) # parseJSONList :: Value -> Parser [Msg e] #
type Rep (Msg e) Source #
Instance details Defined in Mealstrom.FSM type Rep (Msg e) = D1 (MetaData "Msg" "Mealstrom.FSM" "mealstrom-0.0.1.0-1iE9qiPdHB2KeFDL81oqg9" False) (C1 (MetaCons "Msg" PrefixI True) (S1 (MetaSel (Just "msgID") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 (Maybe UUID)) :*: S1 (MetaSel (Just "msgContents") NoSourceUnpackedness NoSourceStrictness DecidedLazy) (Rec0 e)))

mkMsg :: t -> IO (Msg t) Source #

mkMsgs :: [t] -> IO [Msg t] Source #

mkBogusMsg :: Eq t => t -> Msg t Source #

histAppend :: (Eq s, Eq e) => Change s e a -> [Change s e a] -> [Change s e a] Source #

Append a Change to a history. Identical steps are just counted, otherwise they are consed to the history.