graphql/Data/GraphQL/Schema.hs
Danny Navarro bb685c9afa Rough implementation of execute
The first end-to-end test taken from `graphql-js` passes but this still
needs to be extended to support more general cases.

- `Data.GraphQL.Schema` has been heavily modified to support the
  execution model. More drastic changes are expected in this module.
- When defining a `Schema` ordinary functions taking fields as input are
  being used instead of maps. This makes the implementation of `execute`
  easier, and, arguably, makes `Schema` definitions more *Haskellish*.
- Drop explicit `unordered-containers` dependency. `Aeson.Value`s and
  field functions should be good enough for now.
2016-01-26 12:43:18 +01:00

49 lines
1.2 KiB
Haskell

module Data.GraphQL.Schema where
import Data.Maybe (catMaybes)
import Text.Show.Functions ()
import Data.Text (Text)
import Data.Aeson (ToJSON(toJSON))
data Schema = Schema QueryRoot -- (Maybe MutationRoot)
type QueryRoot = Resolver
type Resolver = Input -> Output
data Output = OutputResolver Resolver
| OutputList [Output]
| OutputScalar Scalar
-- | OutputUnion [Output]
-- | OutputEnum [Scalar]
-- | OutputNonNull (Output)
| OutputError
deriving (Show)
data Input = InputScalar Scalar
| InputField Text
| InputList [Input]
deriving (Show)
field :: Input -> Maybe Text
field (InputField x) = Just x
field _ = Nothing
fields :: [Input] -> [Text]
fields = catMaybes . fmap field
data Scalar = ScalarInt Int
| ScalarFloat Double
| ScalarString Text
| ScalarBoolean Bool
| ScalarID Text
deriving (Show)
instance ToJSON Scalar where
toJSON (ScalarInt x) = toJSON x
toJSON (ScalarFloat x) = toJSON x
toJSON (ScalarString x) = toJSON x
toJSON (ScalarBoolean x) = toJSON x
toJSON (ScalarID x) = toJSON x