Mealstrom.FSM

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

Documentation

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

data MealyStatus

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

Constructors

MealyError

Pending

Done

Instances

Eq MealyStatus

Defined in Mealstrom.FSM

Methods

(==) :: MealyStatus -> MealyStatus -> Bool

(/=) :: MealyStatus -> MealyStatus -> Bool

Show MealyStatus

Defined in Mealstrom.FSM

Methods

showsPrec :: Int -> MealyStatus -> ShowS

show :: MealyStatus -> String

showList :: [MealyStatus] -> ShowS

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

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

Methods

toText :: k -> Text

fromText :: Text -> k

Instances

FSMKey Text

Defined in Mealstrom.FSM

Methods

toText :: Text -> Text

fromText :: Text -> Text

FSMKey UUID

Defined in Mealstrom.FSM

Methods

toText :: UUID -> Text

fromText :: Text -> UUID

class FSMKey k => MealyInstance k s e a

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

data Change s e a

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)

Steps are equal to each other when they originated in the same state received the same event and ended up in the same state

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)

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)

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)

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

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)

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)

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)

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)

Defined in Mealstrom.PostgresJSONStore

Methods

fromRow :: RowParser (Instance k s e a)

type Rep (Instance k s e a)

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

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)

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)

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)

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)

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.

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)

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)

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)

Defined in Mealstrom.PostgresJSONStore

Methods

toField :: Machine s e a -> Action

type Rep (Machine s e a)

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

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

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

data Msg e

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)

Defined in Mealstrom.FSM

Methods

(==) :: Msg e -> Msg e -> Bool

(/=) :: Msg e -> Msg e -> Bool

Show e => Show (Msg e)

Defined in Mealstrom.FSM

Methods

showsPrec :: Int -> Msg e -> ShowS

show :: Msg e -> String

showList :: [Msg e] -> ShowS

Generic (Msg e)

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)

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)

Defined in Mealstrom.PostgresJSONStore

Methods

parseJSON :: Value -> Parser (Msg e)

parseJSONList :: Value -> Parser [Msg e]

type Rep (Msg e)

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)

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]

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