4627683 · servant · git.iko.soy

git.iko.soy/servant

Fix TypeError for GHC-9.4

In GHC-9.4 the typechecker changed requiring more annotations in positions like this. See https://gitlab.haskell.org/ghc/ghc/-/wikis/migration/9.4#ambiguous-types-containing-a-typeerror and https://gitlab.haskell.org/ghc/ghc/-/issues/21149

commit4627683a647395f44443fa66d7e92a79eb98cab8 authorTeo Camarasu <teofilcamarasu@gmail.com> dateTue 9 Aug 2022, 11:05 (4 years ago) parente4650de

2 files changed+8−4

compare with master

unifiedsplit

servant-server/src/Servant/Server/Internal.hs+4−2 servant/src/Servant/Links.hs+4−2

servant-server/src/Servant/Server/Internal.hs+4−2

@@ -94,6 +94,8 @@ import Servant.API.TypeErrors

9494import Web.HttpApiData

9595 (FromHttpApiData, parseHeader, parseQueryParam, parseUrlPiece,

9696 parseUrlPieces)

97+import Data.Kind

98+ (Type)

9799

98100import Servant.Server.Internal.BasicAuth

99101import Servant.Server.Internal.Context

@@ -821,7 +823,7 @@ instance (HasContextEntry context (NamedContext name subContext), HasServer subA

821823-------------------------------------------------------------------------------

822824

823825-- Erroring instance for 'HasServer' when a combinator is not fully applied

824−instance TypeError (PartialApplication HasServer arr) => HasServer ((arr :: a -> b) :> sub) context

826+instance TypeError (PartialApplication @(Type -> [Type] -> Constraint) HasServer arr) => HasServer ((arr :: a -> b) :> sub) context

825827 where

826828 type ServerT (arr :> sub) _ = TypeError (PartialApplication (HasServer :: * -> [*] -> Constraint) arr)

827829 route = error "unreachable"

@@ -865,7 +867,7 @@ type HasServerArrowTypeError a b =

865867-- XXX: This omits the @context@ parameter, e.g.:

866868--

867869-- "There is no instance for HasServer (Bool :> …)". Do we care ?

868−instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub HasServer ty) => HasServer (ty :> sub) context

870+instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub @(Type -> [Type] -> Constraint) HasServer ty) => HasServer (ty :> sub) context

869871

870872instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasServer api context)) => HasServer api context

871873

servant/src/Servant/Links.hs+4−2

@@ -193,6 +193,8 @@ import Servant.API.Verbs

193193import Servant.API.WithNamedContext

194194 (WithNamedContext)

195195import Web.HttpApiData

196+import Data.Kind

197+ (Type)

196198

197199-- | A safe link datatype.

198200-- The only way of constructing a 'Link' is using 'safeLink', which means any

@@ -647,12 +649,12 @@ simpleToLink _ toA _ = toLink toA (Proxy :: Proxy sub)

647649-- >>> import Data.Text (Text)

648650

649651-- Erroring instance for 'HasLink' when a combinator is not fully applied

650−instance TypeError (PartialApplication HasLink arr) => HasLink ((arr :: a -> b) :> sub)

652+instance TypeError (PartialApplication @(Type -> Constraint) HasLink arr) => HasLink ((arr :: a -> b) :> sub)

651653 where

652654 type MkLink (arr :> sub) _ = TypeError (PartialApplication (HasLink :: * -> Constraint) arr)

653655 toLink = error "unreachable"

654656

655657-- Erroring instances for 'HasLink' for unknown API combinators

656−instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub HasLink ty) => HasLink (ty :> sub)

658+instance {-# OVERLAPPABLE #-} TypeError (NoInstanceForSub @(Type -> Constraint) HasLink ty) => HasLink (ty :> sub)

657659

658660instance {-# OVERLAPPABLE #-} TypeError (NoInstanceFor (HasLink api)) => HasLink api