Servant.API.Header

Documentation

data Header (sym :: Symbol) a

Extract the given header's value as a value of type a.

Example:

>>> newtype Referer = Referer Text deriving (Eq, Show)
>>> 
>>> -- GET /view-my-referer
>>> type MyApi = "view-my-referer" :> Header "from" Referer :> Get '[JSON] Referer

Constructors

Header a

MissingHeader

UndecodableHeader ByteString

Instances

(KnownSymbol h, ToHttpApiData v) => AddHeader h v (Headers ((:) * fst rest) a) (Headers ((:) * (Header h v) ((:) * fst rest)) a)

Methods

addOptionalHeader :: Header h v -> Headers ((* ': fst) rest) a -> Headers ((* ': Header h v) ((* ': fst) rest)) a

Functor (Header sym)

Methods

fmap :: (a -> b) -> Header sym a -> Header sym b

(<$) :: a -> Header sym b -> Header sym a

(KnownSymbol h, ToHttpApiData x, GetHeaders (HList xs)) => GetHeaders (HList ((:) * (Header h x) xs))

Methods

getHeaders :: HList ((* ': Header h x) xs) -> [Header]

HasLink k sub => HasLink * ((:>) * k (Header sym a) sub)

Associated Types

type MkLink ((* :> k) (Header sym a) sub) (endpoint :: (* :> k) (Header sym a) sub) :: *

Methods

toLink :: Proxy ((* :> k) (Header sym a) sub) endpoint -> Link -> MkLink ((* :> k) (Header sym a) sub) endpoint

Eq a => Eq (Header sym a)

Methods

(==) :: Header sym a -> Header sym a -> Bool

(/=) :: Header sym a -> Header sym a -> Bool

Show a => Show (Header sym a)

Methods

showsPrec :: Int -> Header sym a -> ShowS

show :: Header sym a -> String

showList :: [Header sym a] -> ShowS

(KnownSymbol h, GetHeaders (HList rest), ToHttpApiData v) => GetHeaders (Headers ((:) * (Header h v) rest) a)

Methods

getHeaders :: Headers ((* ': Header h v) rest) a -> [Header]

(FromHttpApiData v, BuildHeadersTo xs, KnownSymbol h) => BuildHeadersTo ((:) * (Header h v) xs)

Methods

buildHeadersTo :: [Header] -> HList ((* ': Header h v) xs)

type MkLink * ((:>) * k (Header sym a) sub)

type MkLink * ((:>) * k (Header sym a) sub) = MkLink k sub