Servant.API.ResponseHeaders

This module provides facilities for adding headers to a response.

>>> let headerVal = addHeader "some-url" 5 :: Headers '[Header "Location" String] Int

The value is added to the header specified by the type (Location in the example above).

Documentation

data Headers ls a

Response Header objects. You should never need to construct one directly. Instead, use addHeader.

Constructors

Headers

Fields

• getResponse :: a

  The underlying value of a Headers

• getHeadersHList :: HList ls

  HList of headers.

Instances

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

Methods

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

Functor (Headers ls)

Methods

fmap :: (a -> b) -> Headers ls a -> Headers ls b

(<$) :: a -> Headers ls b -> Headers ls a

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

Methods

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

GetHeaders (Headers ([] *) a)

Methods

getHeaders :: Headers [*] a -> [Header]

class AddHeader h v orig new | h v orig -> new, new -> h, new -> v, new -> orig where

Minimal complete definition

addHeader

Methods

addHeader :: v -> orig -> new

Instances

(KnownSymbol h, ToByteString v, (~) * new (Headers ((:) * (Header h v) ([] *)) a)) => AddHeader Symbol h v a new

Methods

addHeader :: a -> new -> new

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

Methods

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

class BuildHeadersTo hs where

Minimal complete definition

buildHeadersTo

Methods

buildHeadersTo :: [Header] -> HList hs

Note: if there are multiple occurences of a header in the argument, the values are interspersed with commas before deserialization (see RFC2616 Sec 4.2)

Instances

BuildHeadersTo ([] *)

Methods

buildHeadersTo :: [Header] -> HList [*]

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

Methods

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

class GetHeaders ls where

Minimal complete definition

getHeaders

Methods

getHeaders :: ls -> [Header]

Instances

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

Methods

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

GetHeaders (HList ([] *))

Methods

getHeaders :: HList [*] -> [Header]

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

Methods

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

GetHeaders (Headers ([] *) a)

Methods

getHeaders :: Headers [*] a -> [Header]

type family HeaderValMap (f :: * -> *) (xs :: [*]) where ...

Equations

HeaderValMap f '[] = '[]

HeaderValMap f (Header h x ': xs) = Header h (f x) ': HeaderValMap f xs

data HList a where

Constructors

HNil :: HList '[]

HCons :: Header h x -> HList xs -> HList (Header h x ': xs)

Instances

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

Methods

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

GetHeaders (HList ([] *))

Methods

getHeaders :: HList [*] -> [Header]