Niv.Update

Documentation

type Attrs = HashMap Text (Freedom, Value)

data Update b c where

Constructors

Id :: Update a a

Compose :: Compose b c -> Update b c

Arr :: (b -> c) -> Update b c

First :: Update b c -> Update (b, d) (c, d)

Zero :: Update b c

Plus :: Update b c -> Update b c -> Update b c

Check :: (a -> Bool) -> Update (Box a) ()

Load :: Text -> Update () (Box Value)

UseOrSet :: Text -> Update (Box Value) (Box Value)

Update :: Text -> Update (Box Value) (Box Value)

Run :: (a -> IO b) -> Update (Box a) (Box b)

Template :: Update (Box Text) (Box Text)

Instances

Arrow Update

Defined in Niv.Update

Methods

arr :: (b -> c) -> Update b c

first :: Update b c -> Update (b, d) (c, d)

second :: Update b c -> Update (d, b) (d, c)

(***) :: Update b c -> Update b' c' -> Update (b, b') (c, c')

(&&&) :: Update b c -> Update b c' -> Update b (c, c')

ArrowZero Update

Defined in Niv.Update

Methods

zeroArrow :: Update b c

ArrowPlus Update

Defined in Niv.Update

Methods

(<+>) :: Update b c -> Update b c -> Update b c

Category Update

Defined in Niv.Update

Methods

id :: forall (a :: k). Update a a

(.) :: forall (b :: k) (c :: k) (a :: k). Update b c -> Update a b -> Update a c

Show (Update b c)

Defined in Niv.Update

Methods

showsPrec :: Int -> Update b c -> ShowS

show :: Update b c -> String

showList :: [Update b c] -> ShowS

data Compose a c

Constructors

forall b. Compose' (Update b c) (Update a b)

runUpdate :: Attrs -> Update () a -> IO (Attrs, a)

Run an Update and return the new attributes and result.

execUpdate :: Attrs -> Update () a -> IO a

evalUpdate :: Attrs -> Update () a -> IO Attrs

tryEvalUpdate :: Attrs -> Update () a -> IO (Either SomeException Attrs)

type JSON a = (ToJSON a, FromJSON a)

data UpdateFailed

Constructors

FailNoSuchKey Text

FailZero

FailCheck

FailTemplate Text [Text]

Instances

Show UpdateFailed

Defined in Niv.Update

Methods

showsPrec :: Int -> UpdateFailed -> ShowS

show :: UpdateFailed -> String

showList :: [UpdateFailed] -> ShowS

data UpdateRes a b

Constructors

UpdateReady (UpdateReady b)

UpdateNeedMore (a -> IO (UpdateReady b))

Instances

Functor (UpdateRes a)

Defined in Niv.Update

Methods

fmap :: (a0 -> b) -> UpdateRes a a0 -> UpdateRes a b

(<$) :: a0 -> UpdateRes a b -> UpdateRes a a0

data UpdateReady b

Constructors

UpdateSuccess BoxedAttrs b

UpdateFailed UpdateFailed

Instances

Functor UpdateReady

Defined in Niv.Update

Methods

fmap :: (a -> b) -> UpdateReady a -> UpdateReady b

(<$) :: a -> UpdateReady b -> UpdateReady a

runBox :: Box a -> IO a

data Box a

Constructors

Box

Fields

• boxNew :: Bool

  Whether the value is new or was retrieved (or derived) from old attributes

• boxOp :: IO a

Instances

Functor Box

Defined in Niv.Update

Methods

fmap :: (a -> b) -> Box a -> Box b

(<$) :: a -> Box b -> Box a

Applicative Box

Defined in Niv.Update

Methods

pure :: a -> Box a

(<*>) :: Box (a -> b) -> Box a -> Box b

liftA2 :: (a -> b -> c) -> Box a -> Box b -> Box c

(*>) :: Box a -> Box b -> Box b

(<*) :: Box a -> Box b -> Box a

IsString (Box Text)

Defined in Niv.Update

Methods

fromString :: String -> Box Text

Semigroup a => Semigroup (Box a)

Defined in Niv.Update

Methods

(<>) :: Box a -> Box a -> Box a

sconcat :: NonEmpty (Box a) -> Box a

stimes :: Integral b => b -> Box a -> Box a

mkBox :: Box a -> IO (Box a)

singleton :: MVar (Maybe a) -> IO a -> IO a

type BoxedAttrs = HashMap Text (Freedom, Box Value)

unboxAttrs :: BoxedAttrs -> IO Attrs

boxAttrs :: Attrs -> IO BoxedAttrs

data Freedom

Constructors

Locked

Free

Instances

Eq Freedom

Defined in Niv.Update

Methods

(==) :: Freedom -> Freedom -> Bool

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

Show Freedom

Defined in Niv.Update

Methods

showsPrec :: Int -> Freedom -> ShowS

show :: Freedom -> String

showList :: [Freedom] -> ShowS

runUpdate' :: BoxedAttrs -> Update a b -> IO (UpdateRes a b)

Runs an update, trying to evaluate the Boxes as little as possible. This is a hairy piece of code, apologies ¯_(ツ)_/¯ In most cases I just picked the first implementation that compiled

decodeBox :: FromJSON a => Text -> Box Value -> Box a

decodeValue :: FromJSON a => Text -> Value -> IO a

renderTemplate :: (Text -> Maybe (Box Text)) -> Text -> Maybe (Box Text)

Renders the template. Returns Nothing if some of the attributes are missing. renderTemplate ("foo" -> "bar") "foo" -> pure (Just "bar") renderTemplate ("foo" -> "bar") "baz" -> pure Nothing

template :: Update (Box Text) (Box Text)

check :: (a -> Bool) -> Update (Box a) ()

load :: FromJSON a => Text -> Update () (Box a)

useOrSet :: JSON a => Text -> Update (Box a) (Box a)

update :: JSON a => Text -> Update (Box a) (Box a)

run :: (a -> IO b) -> Update (Box a) (Box b)

run' :: (a -> IO b) -> Update (Box a) (Box b)

Like run but forces evaluation

dirty :: Update (Box a) (Box a)