| Safe Haskell | None |
|---|---|
| Language | Haskell98 |
Web.Spock.Api
- data Endpoint (p :: [*]) (i :: Maybe *) (o :: *) where
- MethodGet :: (ToJSON o, FromJSON o) => Path p Open -> Endpoint p Nothing o
- MethodPost :: (ToJSON i, FromJSON i, ToJSON o, FromJSON o) => Proxy (i -> o) -> Path p Open -> Endpoint p (Just i) o
- MethodPut :: (ToJSON i, FromJSON i, ToJSON o, FromJSON o) => Proxy (i -> o) -> Path p Open -> Endpoint p (Just i) o
- data Proxy k (t :: k) :: forall k. k -> * = Proxy
- type family MaybeToList (a :: Maybe *) :: [*] where ...
- (<//>) :: Path as Open -> Path bs ps -> Path (Append as bs) ps
- var :: (Typeable * a, FromHttpApiData a) => Path ((:) * a ([] *)) Open
- data Path (as :: [*]) (pathState :: PathState) :: [*] -> PathState -> * where
- renderRoute :: AllHave ToHttpApiData as => Path as Open -> HVect as -> Text
- class Generic a
- class ToJSON a
- class FromJSON a
- class NFData a
- class Typeable k (a :: k)
Documentation
data Endpoint (p :: [*]) (i :: Maybe *) (o :: *) where Source #
Describes an endpoint with path parameters, an optional json body and a json response
Constructors
| MethodGet :: (ToJSON o, FromJSON o) => Path p Open -> Endpoint p Nothing o | |
| MethodPost :: (ToJSON i, FromJSON i, ToJSON o, FromJSON o) => Proxy (i -> o) -> Path p Open -> Endpoint p (Just i) o | |
| MethodPut :: (ToJSON i, FromJSON i, ToJSON o, FromJSON o) => Proxy (i -> o) -> Path p Open -> Endpoint p (Just i) o |
data Proxy k (t :: k) :: forall k. k -> * #
A concrete, poly-kinded proxy type
Constructors
| Proxy |
Instances
| Generic1 k (Proxy k) | |
| Monad (Proxy *) | Since: 4.7.0.0 |
| Functor (Proxy *) | Since: 4.7.0.0 |
| Applicative (Proxy *) | Since: 4.7.0.0 |
| Alternative (Proxy *) | Since: 4.9.0.0 |
| MonadPlus (Proxy *) | Since: 4.9.0.0 |
| NFData1 (Proxy *) | Since: 1.4.3.0 |
| Bounded (Proxy k t) | |
| Enum (Proxy k s) | Since: 4.7.0.0 |
| Eq (Proxy k s) | Since: 4.7.0.0 |
| Ord (Proxy k s) | Since: 4.7.0.0 |
| Read (Proxy k s) | Since: 4.7.0.0 |
| Show (Proxy k s) | Since: 4.7.0.0 |
| Ix (Proxy k s) | Since: 4.7.0.0 |
| Generic (Proxy k t) | |
| Monoid (Proxy k s) | Since: 4.7.0.0 |
| NFData (Proxy k a) | Since: 1.4.0.0 |
| type Rep1 k (Proxy k) | |
| type Rep (Proxy k t) | |
type family MaybeToList (a :: Maybe *) :: [*] where ... #
Equations
| MaybeToList (Just * r) = (:) * r ([] *) | |
| MaybeToList (Nothing *) = [] * |
data Path (as :: [*]) (pathState :: PathState) :: [*] -> PathState -> * where #
renderRoute :: AllHave ToHttpApiData as => Path as Open -> HVect as -> Text #
Representable types of kind *. This class is derivable in GHC with the DeriveGeneric flag on.
Instances
A type that can be converted to JSON.
An example type and instance:
-- Allow ourselves to writeTextliterals. {-# LANGUAGE OverloadedStrings #-} data Coord = Coord { x :: Double, y :: Double } instance ToJSON Coord where toJSON (Coord x y) =object["x".=x, "y".=y] toEncoding (Coord x y) =pairs("x".=x<>"y".=y)
Instead of manually writing your ToJSON instance, there are two options
to do it automatically:
- Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so will probably be more efficient than the following two options:
- The compiler can provide a default generic implementation for
toJSON.
To use the second, simply add a deriving clause to your
datatype and declare a GenericToJSON instance for your datatype without giving
definitions for toJSON or toEncoding.
For example, the previous example can be simplified to a more minimal instance:
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics
data Coord = Coord { x :: Double, y :: Double } deriving Generic
instance ToJSON Coord where
toEncoding = genericToEncoding defaultOptions
Why do we provide an implementation for toEncoding here? The
toEncoding function is a relatively new addition to this class.
To allow users of older versions of this library to upgrade without
having to edit all of their instances or encounter surprising
incompatibilities, the default implementation of toEncoding uses
toJSON. This produces correct results, but since it performs an
intermediate conversion to a Value, it will be less efficient
than directly emitting an Encoding. Our one-liner definition of
toEncoding above bypasses the intermediate Value.
If DefaultSignatures doesn't give exactly the results you want,
you can customize the generic encoding with only a tiny amount of
effort, using genericToJSON and genericToEncoding with your
preferred Options:
instance ToJSON Coord where
toJSON = genericToJSON defaultOptions
toEncoding = genericToEncoding defaultOptions
A type that can be converted from JSON, with the possibility of failure.
In many cases, you can get the compiler to generate parsing code for you (see below). To begin, let's cover writing an instance by hand.
There are various reasons a conversion could fail. For example, an
Object could be missing a required key, an Array could be of
the wrong size, or a value could be of an incompatible type.
The basic ways to signal a failed conversion are as follows:
emptyandmzerowork, but are terse and uninformativefailyields a custom error messagetypeMismatchproduces an informative message for cases when the value encountered is not of the expected type
An example type and instance:
-- Allow ourselves to writeTextliterals. {-# LANGUAGE OverloadedStrings #-} data Coord = Coord { x :: Double, y :: Double } instance FromJSON Coord where parseJSON (Objectv) = Coord<$>v.:"x"<*>v.:"y" -- We do not expect a non-Objectvalue here. -- We could usemzeroto fail, buttypeMismatch-- gives a much more informative error message. parseJSON invalid =typeMismatch"Coord" invalid
Instead of manually writing your FromJSON instance, there are two options
to do it automatically:
- Data.Aeson.TH provides Template Haskell functions which will derive an instance at compile time. The generated instance is optimized for your type so will probably be more efficient than the following two options:
- The compiler can provide a default generic implementation for
parseJSON.
To use the second, simply add a deriving clause to your
datatype and declare a GenericFromJSON instance for your datatype without giving
a definition for parseJSON.
For example, the previous example can be simplified to just:
{-# LANGUAGE DeriveGeneric #-}
import GHC.Generics
data Coord = Coord { x :: Double, y :: Double } deriving Generic
instance FromJSON Coord
If DefaultSignatures doesn't give exactly the results you want,
you can customize the generic decoding with only a tiny amount of
effort, using genericParseJSON with your preferred Options:
instance FromJSON Coord where
parseJSON = genericParseJSON defaultOptions
A class of types that can be fully evaluated.
Since: 1.1.0.0
Instances
| NFData Bool | |
| NFData Char | |
| NFData Double | |
| NFData Float | |
| NFData Int | |
| NFData Int8 | |
| NFData Int16 | |
| NFData Int32 | |
| NFData Int64 | |
| NFData Integer | |
| NFData Natural | Since: 1.4.0.0 |
| NFData Ordering | |
| NFData Word | |
| NFData Word8 | |
| NFData Word16 | |
| NFData Word32 | |
| NFData Word64 | |
| NFData CallStack | Since: 1.4.2.0 |
| NFData () | |
| NFData TyCon | NOTE: Only defined for Since: 1.4.0.0 |
| NFData Void | Since: 1.4.0.0 |
| NFData Unique | Since: 1.4.0.0 |
| NFData Version | Since: 1.3.0.0 |
| NFData ThreadId | Since: 1.4.0.0 |
| NFData ExitCode | Since: 1.4.2.0 |
| NFData TypeRep | NOTE: Only defined for Since: 1.4.0.0 |
| NFData All | Since: 1.4.0.0 |
| NFData Any | Since: 1.4.0.0 |
| NFData CChar | Since: 1.4.0.0 |
| NFData CSChar | Since: 1.4.0.0 |
| NFData CUChar | Since: 1.4.0.0 |
| NFData CShort | Since: 1.4.0.0 |
| NFData CUShort | Since: 1.4.0.0 |
| NFData CInt | Since: 1.4.0.0 |
| NFData CUInt | Since: 1.4.0.0 |
| NFData CLong | Since: 1.4.0.0 |
| NFData CULong | Since: 1.4.0.0 |
| NFData CLLong | Since: 1.4.0.0 |
| NFData CULLong | Since: 1.4.0.0 |
| NFData CBool | Since: 1.4.3.0 |
| NFData CFloat | Since: 1.4.0.0 |
| NFData CDouble | Since: 1.4.0.0 |
| NFData CPtrdiff | Since: 1.4.0.0 |
| NFData CSize | Since: 1.4.0.0 |
| NFData CWchar | Since: 1.4.0.0 |
| NFData CSigAtomic | Since: 1.4.0.0 |
| NFData CClock | Since: 1.4.0.0 |
| NFData CTime | Since: 1.4.0.0 |
| NFData CUSeconds | Since: 1.4.0.0 |
| NFData CSUSeconds | Since: 1.4.0.0 |
| NFData CFile | Since: 1.4.0.0 |
| NFData CFpos | Since: 1.4.0.0 |
| NFData CJmpBuf | Since: 1.4.0.0 |
| NFData CIntPtr | Since: 1.4.0.0 |
| NFData CUIntPtr | Since: 1.4.0.0 |
| NFData CIntMax | Since: 1.4.0.0 |
| NFData CUIntMax | Since: 1.4.0.0 |
| NFData Fingerprint | Since: 1.4.0.0 |
| NFData SrcLoc | Since: 1.4.2.0 |
| NFData ZonedTime | |
| NFData LocalTime | |
| NFData UUID | |
| NFData a => NFData [a] | |
| NFData a => NFData (Maybe a) | |
| NFData a => NFData (Ratio a) | |
| NFData (Ptr a) | Since: 1.4.2.0 |
| NFData (FunPtr a) | Since: 1.4.2.0 |
| NFData a => NFData (Complex a) | |
| NFData (Fixed a) | Since: 1.3.0.0 |
| NFData a => NFData (Min a) | Since: 1.4.2.0 |
| NFData a => NFData (Max a) | Since: 1.4.2.0 |
| NFData a => NFData (First a) | Since: 1.4.2.0 |
| NFData a => NFData (Last a) | Since: 1.4.2.0 |
| NFData m => NFData (WrappedMonoid m) | Since: 1.4.2.0 |
| NFData a => NFData (Option a) | Since: 1.4.2.0 |
| NFData a => NFData (NonEmpty a) | Since: 1.4.2.0 |
| NFData (StableName a) | Since: 1.4.0.0 |
| NFData a => NFData (ZipList a) | Since: 1.4.0.0 |
| NFData a => NFData (Identity a) | Since: 1.4.0.0 |
| NFData (IORef a) | NOTE: Only strict in the reference and not the referenced value. Since: 1.4.2.0 |
| NFData a => NFData (Dual a) | Since: 1.4.0.0 |
| NFData a => NFData (Sum a) | Since: 1.4.0.0 |
| NFData a => NFData (Product a) | Since: 1.4.0.0 |
| NFData a => NFData (First a) | Since: 1.4.0.0 |
| NFData a => NFData (Last a) | Since: 1.4.0.0 |
| NFData a => NFData (Down a) | Since: 1.4.0.0 |
| NFData (MVar a) | NOTE: Only strict in the reference and not the referenced value. Since: 1.4.2.0 |
| NFData a => NFData (DList a) | |
| NFData a => NFData (HashSet a) | |
| NFData (Vector a) | |
| NFData (Vector a) | |
| NFData (Vector a) | |
| NFData a => NFData (Vector a) | |
| NFData (a -> b) | This instance is for convenience and consistency with Since: 1.3.0.0 |
| (NFData a, NFData b) => NFData (Either a b) | |
| (NFData a, NFData b) => NFData (a, b) | |
| (NFData a, NFData b) => NFData (Array a b) | |
| (NFData a, NFData b) => NFData (Arg a b) | Since: 1.4.2.0 |
| NFData (Proxy k a) | Since: 1.4.0.0 |
| NFData (STRef s a) | NOTE: Only strict in the reference and not the referenced value. Since: 1.4.2.0 |
| NFData (MVector s a) | |
| (NFData a1, NFData a2, NFData a3) => NFData (a1, a2, a3) | |
| NFData a => NFData (Const k a b) | Since: 1.4.0.0 |
| NFData ((:~:) k a b) | Since: 1.4.3.0 |
| NFData b => NFData (Tagged k s b) | |
| (NFData a1, NFData a2, NFData a3, NFData a4) => NFData (a1, a2, a3, a4) | |
| (NFData1 f, NFData1 g, NFData a) => NFData (Product * f g a) | Since: 1.4.3.0 |
| (NFData1 f, NFData1 g, NFData a) => NFData (Sum * f g a) | Since: 1.4.3.0 |
| NFData ((:~~:) k1 k2 a b) | Since: 1.4.3.0 |
| (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5) => NFData (a1, a2, a3, a4, a5) | |
| (NFData1 f, NFData1 g, NFData a) => NFData (Compose * * f g a) | Since: 1.4.3.0 |
| (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6) => NFData (a1, a2, a3, a4, a5, a6) | |
| (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7) => NFData (a1, a2, a3, a4, a5, a6, a7) | |
| (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7, NFData a8) => NFData (a1, a2, a3, a4, a5, a6, a7, a8) | |
| (NFData a1, NFData a2, NFData a3, NFData a4, NFData a5, NFData a6, NFData a7, NFData a8, NFData a9) => NFData (a1, a2, a3, a4, a5, a6, a7, a8, a9) | |