@@ -1,32 +1,29 @@
1−{-# LANGUAGE AllowAmbiguousTypes #-}
1+{-# LANGUAGE CPP #-}
22{-# LANGUAGE ConstraintKinds #-}
33{-# LANGUAGE DataKinds #-}
44{-# LANGUAGE DeriveDataTypeable #-}
55{-# LANGUAGE FlexibleContexts #-}
66{-# LANGUAGE FlexibleInstances #-}
7−{-# LANGUAGE InstanceSigs #-}
87{-# LANGUAGE MultiParamTypeClasses #-}
98{-# LANGUAGE OverloadedStrings #-}
109{-# LANGUAGE PolyKinds #-}
11−{-# LANGUAGE QuantifiedConstraints #-}
1210{-# LANGUAGE RankNTypes #-}
1311{-# LANGUAGE ScopedTypeVariables #-}
1412{-# LANGUAGE TupleSections #-}
15−{-# LANGUAGE TypeApplications #-}
1613{-# LANGUAGE TypeFamilies #-}
1714{-# LANGUAGE TypeOperators #-}
1815{-# LANGUAGE UndecidableInstances #-}
1916
17+#if MIN_VERSION_base(4,9,0) && __GLASGOW_HASKELL__ >= 802
18+#define HAS_TYPE_ERROR
19+#endif
20+
2021module Servant.Server.Internal
2122 ( module Servant.Server.Internal
2223 , module Servant.Server.Internal.BasicAuth
2324 , module Servant.Server.Internal.Context
24− , module Servant.Server.Internal.Delayed
25− , module Servant.Server.Internal.DelayedIO
26− , module Servant.Server.Internal.ErrorFormatter
2725 , module Servant.Server.Internal.Handler
2826 , module Servant.Server.Internal.Router
29− , module Servant.Server.Internal.RouteResult
3027 , module Servant.Server.Internal.RoutingApplication
3128 , module Servant.Server.Internal.ServerError
3229 ) where
@@ -41,11 +38,12 @@ import qualified Data.ByteString as B
4138import qualified Data.ByteString.Builder as BB
4239import qualified Data.ByteString.Char8 as BC8
4340import qualified Data.ByteString.Lazy as BL
44−import Data.Constraint (Constraint, Dict(..))
4541import Data.Either
4642 (partitionEithers)
4743import Data.Maybe
4844 (fromMaybe, isNothing, mapMaybe, maybeToList)
45+import Data.Semigroup
46+ ((<>))
4947import Data.String
5048 (IsString (..))
5149import Data.String.Conversions
@@ -54,9 +52,8 @@ import Data.Tagged
5452 (Tagged (..), retag, untag)
5553import qualified Data.Text as T
5654import Data.Typeable
57−import GHC.Generics
5855import GHC.TypeLits
59− (KnownNat, KnownSymbol, TypeError, symbolVal)
56+ (KnownNat, KnownSymbol, natVal, symbolVal)
6057import qualified Network.HTTP.Media as NHM
6158import Network.HTTP.Types hiding
6259 (Header, ResponseHeaders)
@@ -64,52 +61,42 @@ import Network.Socket
6461 (SockAddr)
6562import Network.Wai
6663 (Application, Request, httpVersion, isSecure, lazyRequestBody,
67− queryString, remoteHost, getRequestBodyChunk, requestHeaders,
64+ rawQueryString, remoteHost, requestBody, requestHeaders,
6865 requestMethod, responseLBS, responseStream, vault)
6966import Prelude ()
7067import Prelude.Compat
7168import Servant.API
7269 ((:<|>) (..), (:>), Accept (..), BasicAuth, Capture',
73− CaptureAll, Description, EmptyAPI, Fragment,
74− FramingRender (..), FramingUnrender (..), FromSourceIO (..),
75− Header', If, IsSecure (..), NoContentVerb, QueryFlag,
76− QueryParam', QueryParams, Raw, ReflectMethod (reflectMethod),
77− RemoteHost, ReqBody', SBool (..), SBoolI (..), SourceIO,
78− Stream, StreamBody', Summary, ToSourceIO (..), Vault, Verb,
79− WithNamedContext, NamedRoutes)
80−import Servant.API.Generic (GenericMode(..), ToServant, ToServantApi, GServantProduct, toServant, fromServant)
70+ CaptureAll, Description, EmptyAPI, FramingRender (..),
71+ FramingUnrender (..), FromSourceIO (..), Header', If,
72+ IsSecure (..), QueryFlag, QueryParam', QueryParams, Raw,
73+ ReflectMethod (reflectMethod), RemoteHost, ReqBody',
74+ SBool (..), SBoolI (..), SourceIO, Stream, StreamBody',
75+ Summary, ToSourceIO (..), Vault, Verb, WithNamedContext)
8176import Servant.API.ContentTypes
8277 (AcceptHeader (..), AllCTRender (..), AllCTUnrender (..),
83− AllMime, MimeRender (..), MimeUnrender (..), NoContent,
84− canHandleAcceptH)
78+ AllMime, MimeRender (..), MimeUnrender (..), canHandleAcceptH)
8579import Servant.API.Modifiers
8680 (FoldLenient, FoldRequired, RequestArgument,
8781 unfoldRequestArgument)
8882import Servant.API.ResponseHeaders
8983 (GetHeaders, Headers, getHeaders, getResponse)
90−import Servant.API.Status
91− (statusFromNat)
9284import qualified Servant.Types.SourceT as S
93−import Servant.API.TypeErrors
9485import Web.HttpApiData
95− (FromHttpApiData, parseHeader, parseQueryParam, parseUrlPiece,
96− parseUrlPieces)
86+ (FromHttpApiData, parseHeader, parseQueryParam,
87+ parseUrlPieceMaybe, parseUrlPieces)
9788
9889import Servant.Server.Internal.BasicAuth
9990import Servant.Server.Internal.Context
100−import Servant.Server.Internal.Delayed
101−import Servant.Server.Internal.DelayedIO
102−import Servant.Server.Internal.ErrorFormatter
10391import Servant.Server.Internal.Handler
10492import Servant.Server.Internal.Router
105−import Servant.Server.Internal.RouteResult
10693import Servant.Server.Internal.RoutingApplication
10794import Servant.Server.Internal.ServerError
10895
96+#ifdef HAS_TYPE_ERROR
10997import GHC.TypeLits
11098 (ErrorMessage (..), TypeError)
111−import Servant.API.TypeLevel
112− (AtLeastOneFragment, FragmentUnique)
99+#endif
113100
114101class HasServer api context where
115102 type ServerT api (m :: * -> *) :: *
@@ -173,31 +160,22 @@ instance (HasServer a context, HasServer b context) => HasServer (a :<|> b) cont
173160-- > server = getBook
174161-- > where getBook :: Text -> Handler Book
175162-- > getBook isbn = ...
176−instance (KnownSymbol capture, FromHttpApiData a, Typeable a
177− , HasServer api context, SBoolI (FoldLenient mods)
178− , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters
179− )
163+instance (KnownSymbol capture, FromHttpApiData a, HasServer api context)
180164 => HasServer (Capture' mods capture a :> api) context where
181165
182166 type ServerT (Capture' mods capture a :> api) m =
183− If (FoldLenient mods) (Either String a) a -> ServerT api m
167+ a -> ServerT api m
184168
185169 hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy :: Proxy api) pc nt . s
186170
187171 route Proxy context d =
188− CaptureRouter [hint] $
172+ CaptureRouter $
189173 route (Proxy :: Proxy api)
190174 context
191− (addCapture d $ \ txt -> withRequest $ \ request ->
192− case ( sbool :: SBool (FoldLenient mods)
193− , parseUrlPiece txt :: Either T.Text a) of
194− (SFalse, Left e) -> delayedFail $ formatError rep request $ cs e
195− (SFalse, Right v) -> return v
196− (STrue, piece) -> return $ (either (Left . cs) Right) piece)
197− where
198− rep = typeRep (Proxy :: Proxy Capture')
199− formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
200− hint = CaptureHint (T.pack $ symbolVal $ Proxy @capture) (typeRep (Proxy :: Proxy a))
175+ (addCapture d $ \ txt -> case parseUrlPieceMaybe txt of
176+ Nothing -> delayedFail err400
177+ Just v -> return v
178+ )
201179
202180-- | If you use 'CaptureAll' in one of the endpoints for your API,
203181-- this automatically requires your server-side handler to be a
@@ -216,10 +194,7 @@ instance (KnownSymbol capture, FromHttpApiData a, Typeable a
216194-- > server = getSourceFile
217195-- > where getSourceFile :: [Text] -> Handler Book
218196-- > getSourceFile pathSegments = ...
219−instance (KnownSymbol capture, FromHttpApiData a, Typeable a
220− , HasServer api context
221− , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters
222− )
197+instance (KnownSymbol capture, FromHttpApiData a, HasServer api context)
223198 => HasServer (CaptureAll capture a :> api) context where
224199
225200 type ServerT (CaptureAll capture a :> api) m =
@@ -228,18 +203,14 @@ instance (KnownSymbol capture, FromHttpApiData a, Typeable a
228203 hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy :: Proxy api) pc nt . s
229204
230205 route Proxy context d =
231− CaptureAllRouter [hint] $
206+ CaptureAllRouter $
232207 route (Proxy :: Proxy api)
233208 context
234− (addCapture d $ \ txts -> withRequest $ \ request ->
235− case parseUrlPieces txts of
236− Left e -> delayedFail $ formatError rep request $ cs e
237− Right v -> return v
209+ (addCapture d $ \ txts -> case parseUrlPieces txts of
210+ Left _ -> delayedFail err400
211+ Right v -> return v
238212 )
239− where
240− rep = typeRep (Proxy :: Proxy CaptureAll)
241− formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
242− hint = CaptureHint (T.pack $ symbolVal $ Proxy @capture) (typeRep (Proxy :: Proxy [a]))
213+
243214
244215allowedMethodHead :: Method -> Request -> Bool
245216allowedMethodHead method request = method == methodGet && requestMethod request == methodHead
@@ -259,10 +230,10 @@ methodCheck method request
259230-- body check is no longer an option. However, we now run the accept
260231-- check before the body check and can therefore afford to make it
261232-- recoverable.
262−acceptCheck :: (AllMime list) => Proxy list -> AcceptHeader -> DelayedIO ()
233+acceptCheck :: (AllMime list) => Proxy list -> B.ByteString -> DelayedIO ()
263234acceptCheck proxy accH
264− | canHandleAcceptH proxy accH = return ()
265− | otherwise = delayedFail err406
235+ | canHandleAcceptH proxy (AcceptHeader accH) = return ()
236+ | otherwise = delayedFail err406
266237
267238methodRouter :: (AllCTRender ctypes a)
268239 => (b -> ([(HeaderName, B.ByteString)], a))
@@ -272,28 +243,17 @@ methodRouter :: (AllCTRender ctypes a)
272243methodRouter splitHeaders method proxy status action = leafRouter route'
273244 where
274245 route' env request respond =
275− let accH = getAcceptHeader request
246+ let accH = fromMaybe ct_wildcard $ lookup hAccept $ requestHeaders request
276247 in runAction (action `addMethodCheck` methodCheck method request
277248 `addAcceptCheck` acceptCheck proxy accH
278249 ) env request respond $ \ output -> do
279250 let (headers, b) = splitHeaders output
280− case handleAcceptH proxy accH b of
251+ case handleAcceptH proxy (AcceptHeader accH) b of
281252 Nothing -> FailFatal err406 -- this should not happen (checked before), so we make it fatal if it does
282253 Just (contentT, body) ->
283254 let bdy = if allowedMethodHead method request then "" else body
284255 in Route $ responseLBS status ((hContentType, cs contentT) : headers) bdy
285256
286−noContentRouter :: Method
287− -> Status
288− -> Delayed env (Handler b)
289− -> Router env
290−noContentRouter method status action = leafRouter route'
291− where
292− route' env request respond =
293− runAction (action `addMethodCheck` methodCheck method request)
294− env request respond $ \ _output ->
295− Route $ responseLBS status [] ""
296−
297257instance {-# OVERLAPPABLE #-}
298258 ( AllCTRender ctypes a, ReflectMethod method, KnownNat status
299259 ) => HasServer (Verb method status ctypes a) context where
@@ -303,7 +263,7 @@ instance {-# OVERLAPPABLE #-}
303263
304264 route Proxy _ = methodRouter ([],) method (Proxy :: Proxy ctypes) status
305265 where method = reflectMethod (Proxy :: Proxy method)
306− status = statusFromNat (Proxy :: Proxy status)
266+ status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
307267
308268instance {-# OVERLAPPING #-}
309269 ( AllCTRender ctypes a, ReflectMethod method, KnownNat status
@@ -315,16 +275,8 @@ instance {-# OVERLAPPING #-}
315275
316276 route Proxy _ = methodRouter (\x -> (getHeaders x, getResponse x)) method (Proxy :: Proxy ctypes) status
317277 where method = reflectMethod (Proxy :: Proxy method)
318− status = statusFromNat (Proxy :: Proxy status)
319−
320−instance (ReflectMethod method) =>
321− HasServer (NoContentVerb method) context where
278+ status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
322279
323− type ServerT (NoContentVerb method) m = m NoContent
324− hoistServerWithContext _ _ nt s = nt s
325−
326− route Proxy _ = noContentRouter method status204
327− where method = reflectMethod (Proxy :: Proxy method)
328280
329281instance {-# OVERLAPPABLE #-}
330282 ( MimeRender ctype chunk, ReflectMethod method, KnownNat status,
@@ -336,7 +288,7 @@ instance {-# OVERLAPPABLE #-}
336288
337289 route Proxy _ = streamRouter ([],) method status (Proxy :: Proxy framing) (Proxy :: Proxy ctype)
338290 where method = reflectMethod (Proxy :: Proxy method)
339− status = statusFromNat (Proxy :: Proxy status)
291+ status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
340292
341293
342294instance {-# OVERLAPPING #-}
@@ -350,7 +302,7 @@ instance {-# OVERLAPPING #-}
350302
351303 route Proxy _ = streamRouter (\x -> (getHeaders x, getResponse x)) method status (Proxy :: Proxy framing) (Proxy :: Proxy ctype)
352304 where method = reflectMethod (Proxy :: Proxy method)
353− status = statusFromNat (Proxy :: Proxy status)
305+ status = toEnum . fromInteger $ natVal (Proxy :: Proxy status)
354306
355307
356308streamRouter :: forall ctype a c chunk env framing. (MimeRender ctype chunk, FramingRender framing, ToSourceIO chunk a) =>
@@ -362,7 +314,7 @@ streamRouter :: forall ctype a c chunk env framing. (MimeRender ctype chunk, Fra
362314 -> Delayed env (Handler c)
363315 -> Router env
364316streamRouter splitHeaders method status framingproxy ctypeproxy action = leafRouter $ \env request respond ->
365− let AcceptHeader accH = getAcceptHeader request
317+ let accH = fromMaybe ct_wildcard $ lookup hAccept $ requestHeaders request
366318 cmediatype = NHM.matchAccept [contentType ctypeproxy] accH
367319 accCheck = when (isNothing cmediatype) $ delayedFail err406
368320 contentHeader = (hContentType, NHM.renderHeader . maybeToList $ cmediatype)
@@ -407,7 +359,6 @@ streamRouter splitHeaders method status framingproxy ctypeproxy action = leafRou
407359instance
408360 (KnownSymbol sym, FromHttpApiData a, HasServer api context
409361 , SBoolI (FoldRequired mods), SBoolI (FoldLenient mods)
410− , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters
411362 )
412363 => HasServer (Header' mods sym a :> api) context where
413364------
@@ -419,9 +370,6 @@ instance
419370 route Proxy context subserver = route (Proxy :: Proxy api) context $
420371 subserver `addHeaderCheck` withRequest headerCheck
421372 where
422− rep = typeRep (Proxy :: Proxy Header')
423− formatError = headerParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
424−
425373 headerName :: IsString n => n
426374 headerName = fromString $ symbolVal (Proxy :: Proxy sym)
427375
@@ -432,13 +380,15 @@ instance
432380 mev :: Maybe (Either T.Text a)
433381 mev = fmap parseHeader $ lookup headerName (requestHeaders req)
434382
435− errReq = delayedFailFatal $ formatError rep req
436− $ "Header " <> headerName <> " is required"
383+ errReq = delayedFailFatal err400
384+ { errBody = "Header " <> headerName <> " is required"
385+ }
437386
438− errSt e = delayedFailFatal $ formatError rep req
439− $ cs $ "Error parsing header "
440− <> headerName
441− <> " failed: " <> e
387+ errSt e = delayedFailFatal err400
388+ { errBody = cs $ "Error parsing header "
389+ <> headerName
390+ <> " failed: " <> e
391+ }
442392
443393-- | If you use @'QueryParam' "author" Text@ in one of the endpoints for your API,
444394-- this automatically requires your server-side handler to be a function
@@ -464,7 +414,6 @@ instance
464414instance
465415 ( KnownSymbol sym, FromHttpApiData a, HasServer api context
466416 , SBoolI (FoldRequired mods), SBoolI (FoldLenient mods)
467− , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters
468417 )
469418 => HasServer (QueryParam' mods sym a :> api) context where
470419------
@@ -474,12 +423,9 @@ instance
474423 hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy :: Proxy api) pc nt . s
475424
476425 route Proxy context subserver =
477− let querytext = queryToQueryText . queryString
426+ let querytext req = parseQueryText $ rawQueryString req
478427 paramname = cs $ symbolVal (Proxy :: Proxy sym)
479428
480− rep = typeRep (Proxy :: Proxy QueryParam')
481− formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
482−
483429 parseParam :: Request -> DelayedIO (RequestArgument mods a)
484430 parseParam req =
485431 unfoldRequestArgument (Proxy :: Proxy mods) errReq errSt mev
@@ -487,12 +433,14 @@ instance
487433 mev :: Maybe (Either T.Text a)
488434 mev = fmap parseQueryParam $ join $ lookup paramname $ querytext req
489435
490− errReq = delayedFailFatal $ formatError rep req
491− $ cs $ "Query parameter " <> paramname <> " is required"
436+ errReq = delayedFailFatal err400
437+ { errBody = cs $ "Query parameter " <> paramname <> " is required"
438+ }
492439
493− errSt e = delayedFailFatal $ formatError rep req
494− $ cs $ "Error parsing query parameter "
495− <> paramname <> " failed: " <> e
440+ errSt e = delayedFailFatal err400
441+ { errBody = cs $ "Error parsing query parameter "
442+ <> paramname <> " failed: " <> e
443+ }
496444
497445 delayed = addParameterCheck subserver . withRequest $ \req ->
498446 parseParam req
@@ -518,8 +466,7 @@ instance
518466-- > server = getBooksBy
519467-- > where getBooksBy :: [Text] -> Handler [Book]
520468-- > getBooksBy authors = ...return all books by these authors...
521−instance (KnownSymbol sym, FromHttpApiData a, HasServer api context
522− , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters)
469+instance (KnownSymbol sym, FromHttpApiData a, HasServer api context)
523470 => HasServer (QueryParams sym a :> api) context where
524471
525472 type ServerT (QueryParams sym a :> api) m =
@@ -530,23 +477,21 @@ instance (KnownSymbol sym, FromHttpApiData a, HasServer api context
530477 route Proxy context subserver = route (Proxy :: Proxy api) context $
531478 subserver `addParameterCheck` withRequest paramsCheck
532479 where
533− rep = typeRep (Proxy :: Proxy QueryParams)
534− formatError = urlParseErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
535−
536480 paramname = cs $ symbolVal (Proxy :: Proxy sym)
537481 paramsCheck req =
538482 case partitionEithers $ fmap parseQueryParam params of
539483 ([], parsed) -> return parsed
540− (errs, _) -> delayedFailFatal $ formatError rep req
541− $ cs $ "Error parsing query parameter(s) "
542− <> paramname <> " failed: "
543− <> T.intercalate ", " errs
484+ (errs, _) -> delayedFailFatal err400
485+ { errBody = cs $ "Error parsing query parameter(s) "
486+ <> paramname <> " failed: "
487+ <> T.intercalate ", " errs
488+ }
544489 where
545490 params :: [T.Text]
546491 params = mapMaybe snd
547492 . filter (looksLikeParam . fst)
548− . queryToQueryText
549− . queryString
493+ . parseQueryText
494+ . rawQueryString
550495 $ req
551496
552497 looksLikeParam name = name == paramname || name == (paramname <> "[]")
@@ -572,7 +517,7 @@ instance (KnownSymbol sym, HasServer api context)
572517 hoistServerWithContext _ pc nt s = hoistServerWithContext (Proxy :: Proxy api) pc nt . s
573518
574519 route Proxy context subserver =
575− let querytext = queryToQueryText . queryString
520+ let querytext r = parseQueryText $ rawQueryString r
576521 param r = case lookup paramname (querytext r) of
577522 Just Nothing -> True -- param is there, with no value
578523 Just (Just v) -> examine v -- param with a value
@@ -614,7 +559,7 @@ instance HasServer Raw context where
614559-- The @Content-Type@ header is inspected, and the list provided is used to
615560-- attempt deserialization. If the request does not have a @Content-Type@
616561-- header, it is treated as @application/octet-stream@ (as specified in
617−-- [RFC 7231 section 3.1.1.5](http://tools.ietf.org/html/rfc7231#section-3.1.1.5)).
562+-- <http://tools.ietf.org/html/rfc7231#section-3.1.1.5 RFC7231>.
618563-- This lets servant worry about extracting it from the request and turning
619564-- it into a value of the type you specify.
620565--
@@ -630,7 +575,6 @@ instance HasServer Raw context where
630575-- > where postBook :: Book -> Handler Book
631576-- > postBook book = ...insert into your db...
632577instance ( AllCTUnrender list a, HasServer api context, SBoolI (FoldLenient mods)
633− , HasContextEntry (MkContextWithErrorFormatter context) ErrorFormatters
634578 ) => HasServer (ReqBody' mods list a :> api) context where
635579
636580 type ServerT (ReqBody' mods list a :> api) m =
@@ -642,9 +586,6 @@ instance ( AllCTUnrender list a, HasServer api context, SBoolI (FoldLenient mods
642586 = route (Proxy :: Proxy api) context $
643587 addBodyCheck subserver ctCheck bodyCheck
644588 where
645− rep = typeRep (Proxy :: Proxy ReqBody')
646− formatError = bodyParserErrorFormatter $ getContextEntry (mkContextWithErrorFormatter context)
647−
648589 -- Content-Type check, we only lookup we can try to parse the request body
649590 ctCheck = withRequest $ \ request -> do
650591 -- See HTTP RFC 2616, section 7.2.1
@@ -663,7 +604,7 @@ instance ( AllCTUnrender list a, HasServer api context, SBoolI (FoldLenient mods
663604 case sbool :: SBool (FoldLenient mods) of
664605 STrue -> return mrqbody
665606 SFalse -> case mrqbody of
666− Left e -> delayedFailFatal $ formatError rep request e
607+ Left e -> delayedFailFatal err400 { errBody = cs e }
667608 Right v -> return v
668609
669610instance
@@ -686,7 +627,7 @@ instance
686627 bodyCheck fromRS = withRequest $ \req -> do
687628 let mimeUnrender' = mimeUnrender (Proxy :: Proxy ctype) :: BL.ByteString -> Either String chunk
688629 let framingUnrender' = framingUnrender (Proxy :: Proxy framing) mimeUnrender' :: SourceIO B.ByteString -> SourceIO chunk
689− let body = getRequestBodyChunk req
630+ let body = requestBody req
690631 let rs = S.fromAction B.null body
691632 let rs' = fromRS $ framingUnrender' rs
692633 return rs'
@@ -755,12 +696,12 @@ data EmptyServer = EmptyServer deriving (Typeable, Eq, Show, Bounded, Enum)
755696emptyServer :: ServerT EmptyAPI m
756697emptyServer = Tagged EmptyServer
757698
758−-- | The server for an `EmptyAPI` is `emptyServer`.
699+-- | The server for an `EmptyAPI` is `emptyAPIServer`.
759700--
760701-- > type MyApi = "nothing" :> EmptyApi
761702-- >
762703-- > server :: Server MyApi
763−-- > server = emptyServer
704+-- > server = emptyAPIServer
764705instance HasServer EmptyAPI context where
765706 type ServerT EmptyAPI m = Tagged m EmptyServer
766707
@@ -789,10 +730,7 @@ instance ( KnownSymbol realm
789730-- * helpers
790731
791732ct_wildcard :: B.ByteString
792−ct_wildcard = "*" <> "/" <> "*"
793−
794−getAcceptHeader :: Request -> AcceptHeader
795−getAcceptHeader = AcceptHeader . fromMaybe ct_wildcard . lookup hAccept . requestHeaders
733+ct_wildcard = "*" <> "/" <> "*" -- Because CPP
796734
797735-- * General Authentication
798736
@@ -817,15 +755,39 @@ instance (HasContextEntry context (NamedContext name subContext), HasServer subA
817755 hoistServerWithContext _ _ nt s = hoistServerWithContext (Proxy :: Proxy subApi) (Proxy :: Proxy subContext) nt s
818756
819757-------------------------------------------------------------------------------
820−-- Custom type errors
758+-- TypeError helpers
821759-------------------------------------------------------------------------------
822760
823−-- Erroring instance for 'HasServer' when a combinator is not fully applied
824−instance TypeError (PartialApplication HasServer arr) => HasServer ((arr :: a -> b) :> sub) context
761+#ifdef HAS_TYPE_ERROR
762+-- | This instance catches mistakes when there are non-saturated
763+-- type applications on LHS of ':>'.
764+--
765+-- >>> serve (Proxy :: Proxy (Capture "foo" :> Get '[JSON] Int)) (error "...")
766+-- ...
767+-- ...Expected something of kind Symbol or *, got: k -> l on the LHS of ':>'.
768+-- ...Maybe you haven't applied enough arguments to
769+-- ...Capture' '[] "foo"
770+-- ...
771+--
772+-- >>> undefined :: Server (Capture "foo" :> Get '[JSON] Int)
773+-- ...
774+-- ...Expected something of kind Symbol or *, got: k -> l on the LHS of ':>'.
775+-- ...Maybe you haven't applied enough arguments to
776+-- ...Capture' '[] "foo"
777+-- ...
778+--
779+instance TypeError (HasServerArrowKindError arr) => HasServer ((arr :: k -> l) :> api) context
825780 where
826− type ServerT (arr :> sub) _ = TypeError (PartialApplication (HasServer :: * -> [*] -> Constraint) arr)
827− route = error "unreachable"
828− hoistServerWithContext _ _ _ _ = error "unreachable"
781+ type ServerT (arr :> api) m = TypeError (HasServerArrowKindError arr)
782+ -- it doens't really matter what sub route we peak
783+ route _ _ _ = error "servant-server panic: impossible happened in HasServer (arr :> api)"
784+ hoistServerWithContext _ _ _ = id
785+
786+-- Cannot have TypeError here, otherwise use of this symbol will error :)
787+type HasServerArrowKindError arr =
788+ 'Text "Expected something of kind Symbol or *, got: k -> l on the LHS of ':>'."
789+ ':$$: 'Text "Maybe you haven't applied enough arguments to"
790+ ':$$: 'ShowType arr
829791
830792-- | This instance prevents from accidentally using '->' instead of ':>'
831793--
@@ -859,103 +821,7 @@ type HasServerArrowTypeError a b =
859821 ':$$: 'ShowType a
860822 ':$$: 'Text "and"
861823 ':$$: 'ShowType b
862−
863−-- Erroring instances for 'HasServer' for unknown API combinators
864−
865−-- XXX: This omits the @context@ parameter, e.g.:
866−--
867−-- "There is no instance for HasServer (Bool :> …)". Do we care ?
868−instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub HasServer ty) => HasServer (ty :> sub) context
869−
870−instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasServer api context)) => HasServer api context
871−
872−-- | Ignore @'Fragment'@ in server handlers.
873−-- See <https://ietf.org/rfc/rfc2616.html#section-15.1.3> for more details.
874−--
875−-- Example:
876−--
877−-- > type MyApi = "books" :> Fragment Text :> Get '[JSON] [Book]
878−-- >
879−-- > server :: Server MyApi
880−-- > server = getBooks
881−-- > where getBooks :: Handler [Book]
882−-- > getBooks = ...return all books...
883−instance (AtLeastOneFragment api, FragmentUnique (Fragment a1 :> api), HasServer api context)
884− => HasServer (Fragment a1 :> api) context where
885− type ServerT (Fragment a1 :> api) m = ServerT api m
886−
887− route _ = route (Proxy :: Proxy api)
888−
889− hoistServerWithContext _ = hoistServerWithContext (Proxy :: Proxy api)
824+#endif
890825
891826-- $setup
892827-- >>> import Servant
893−
894−-- | A type that specifies that an API record contains a server implementation.
895−data AsServerT (m :: * -> *)
896−instance GenericMode (AsServerT m) where
897− type AsServerT m :- api = ServerT api m
898−
899−type AsServer = AsServerT Handler
900−
901−
902−-- | Set of constraints required to convert to / from vanilla server types.
903−type GServerConstraints api m =
904− ( ToServant api (AsServerT m) ~ ServerT (ToServantApi api) m
905− , GServantProduct (Rep (api (AsServerT m)))
906− )
907−
908−-- | This class is a necessary evil: in the implementation of 'HasServer' for
909−-- @'NamedRoutes' api@, we essentially need the quantified constraint @forall
910−-- m. 'GServerConstraints' m@ to hold.
911−--
912−-- We cannot require do that directly as the definition of 'GServerConstraints'
913−-- contains type family applications ('Rep' and 'ServerT'). The trick is to hide
914−-- those type family applications behind a typeclass providing evidence for
915−-- @'GServerConstraints' api m@ in the form of a dictionary, and require that
916−-- @forall m. 'GServer' api m@ instead.
917−--
918−-- Users shouldn't have to worry about this class, as the only possible instance
919−-- is provided in this module for all record APIs.
920−
921−class GServer (api :: * -> *) (m :: * -> *) where
922− gServerProof :: Dict (GServerConstraints api m)
923−
924−instance
925− ( ToServant api (AsServerT m) ~ ServerT (ToServantApi api) m
926− , GServantProduct (Rep (api (AsServerT m)))
927− ) => GServer api m where
928− gServerProof = Dict
929−
930−instance
931− ( HasServer (ToServantApi api) context
932− , forall m. Generic (api (AsServerT m))
933− , forall m. GServer api m
934− ) => HasServer (NamedRoutes api) context where
935−
936− type ServerT (NamedRoutes api) m = api (AsServerT m)
937−
938− route
939− :: Proxy (NamedRoutes api)
940− -> Context context
941− -> Delayed env (api (AsServerT Handler))
942− -> Router env
943− route _ ctx delayed =
944− case gServerProof @api @Handler of
945− Dict -> route (Proxy @(ToServantApi api)) ctx (toServant <$> delayed)
946−
947− hoistServerWithContext
948− :: forall m n. Proxy (NamedRoutes api)
949− -> Proxy context
950− -> (forall x. m x -> n x)
951− -> api (AsServerT m)
952− -> api (AsServerT n)
953− hoistServerWithContext _ pctx nat server =
954− case (gServerProof @api @m, gServerProof @api @n) of
955− (Dict, Dict) ->
956− fromServant servantSrvN
957− where
958− servantSrvM :: ServerT (ToServantApi api) m =
959− toServant server
960− servantSrvN :: ServerT (ToServantApi api) n =
961− hoistServerWithContext (Proxy @(ToServantApi api)) pctx nat servantSrvM