From 09135c581aaae471f7d964bc2a3a141bef299097 Mon Sep 17 00:00:00 2001 From: Eugen Wissner Date: Fri, 17 Jul 2020 07:05:03 +0200 Subject: Constrain base monad to MonadCatch Let's try MonadThrow/MonadCatch. It looks nice at a first glance. The monad transformer stack contains only the ReaderT, less lifts are required. Exception subtyping is easier, the user can (and should) define custom error types and throw them. And it is still possible to use pure error handling, if someone doesn't like runtime exceptions or need to run a query in a pure environment. Fixes #42. --- src/Language/GraphQL/Execute.hs | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'src/Language/GraphQL/Execute.hs') diff --git a/src/Language/GraphQL/Execute.hs b/src/Language/GraphQL/Execute.hs index 08aa5ab..2b615f4 100644 --- a/src/Language/GraphQL/Execute.hs +++ b/src/Language/GraphQL/Execute.hs @@ -6,6 +6,7 @@ module Language.GraphQL.Execute , module Language.GraphQL.Execute.Coerce ) where +import Control.Monad.Catch (MonadCatch) import Data.HashMap.Strict (HashMap) import Data.Sequence (Seq(..)) import Data.Text (Text) @@ -25,7 +26,7 @@ import Language.GraphQL.Type.Schema -- -- Returns the result of the query against the schema wrapped in a /data/ -- field, or errors wrapped in an /errors/ field. -execute :: (Monad m, VariableValue a, Serialize b) +execute :: (MonadCatch m, VariableValue a, Serialize b) => Schema m -- ^ Resolvers. -> Maybe Text -- ^ Operation name. -> HashMap Name a -- ^ Variable substitution function. @@ -39,7 +40,7 @@ execute schema operationName subs document = $ Transform.queryError queryError Right transformed -> executeRequest transformed -executeRequest :: (Monad m, Serialize a) +executeRequest :: (MonadCatch m, Serialize a) => Transform.Document m -> m (Either (ResponseEventStream m a) (Response a)) executeRequest (Transform.Document types' rootObjectType operation) @@ -53,7 +54,7 @@ executeRequest (Transform.Document types' rootObjectType operation) -- This is actually executeMutation, but we don't distinguish between queries -- and mutations yet. -executeOperation :: (Monad m, Serialize a) +executeOperation :: (MonadCatch m, Serialize a) => HashMap Name (Type m) -> Out.ObjectType m -> Seq (Transform.Selection m) -- cgit v1.2.3