Data.Registry.Options.Decoder

This module contains the definition of a Decoder and some default decoders

A Decoder reads a string and return a Haskell value or a failure

Documentation

newtype Decoder a

Decode a value of type a from Text

Constructors

Decoder

Fields

• decode :: Text -> Either Text a

Instances

Applicative Decoder

Defined in Data.Registry.Options.Decoder

Methods

pure :: a -> Decoder a

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

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

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

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

Functor Decoder

Defined in Data.Registry.Options.Decoder

Methods

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

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

Monad Decoder

Defined in Data.Registry.Options.Decoder

Methods

(>>=) :: Decoder a -> (a -> Decoder b) -> Decoder b

(>>) :: Decoder a -> Decoder b -> Decoder b

return :: a -> Decoder a

decoderOf :: forall a b. (ApplyVariadic Decoder a b, Typeable a, Typeable b) => a -> Typed b

Create a Decoder a for a given constructor of type a

addDecoder :: forall a. Typeable a => (Text -> Either Text a) -> Typed (Decoder a)

Add a Decoder to a registry

Common decoders

intDecoder :: Text -> Either Text Int

Decoder for an Int

boolDecoder :: Text -> Either Text Bool

Decoder for a Bool

textDecoder :: Text -> Either Text Text

Decoder for some Text

stringDecoder :: Text -> Either Text String

Decoder for some String

manyOf :: forall a. Typeable a => Typed (Decoder a -> Decoder [a])

Create a Decoder for [a]

decodeMany :: forall a. Typeable a => Decoder a -> Decoder [a]

Create a Decoder for [a] as a comma-separated string

decodeManySeparated :: forall a. Typeable a => Text -> Decoder a -> Decoder [a]

Create a Decoder for [a] as a separated string