forked from OSS/graphql
a088c81944
The `Schema` has been overhauled to make `Output` monomorphic. Traversing the `GraphQL` document is handled implicitly while defining the `Schema`. The 4th end-to-end test from `graphql-js` has been ported.
48 lines
1.7 KiB
Haskell
48 lines
1.7 KiB
Haskell
{-# LANGUAGE CPP #-}
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{-# LANGUAGE LambdaCase #-}
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module Data.GraphQL.Execute where
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#if !MIN_VERSION_base(4,8,0)
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import Control.Applicative ((<$>), pure)
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import Data.Traversable (traverse)
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#endif
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import Control.Applicative (Alternative, empty)
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import Data.Foldable (fold)
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import qualified Data.Aeson as Aeson
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import qualified Data.HashMap.Strict as HashMap
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import Data.GraphQL.AST
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import Data.GraphQL.Schema (Resolver, Schema(..))
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import qualified Data.GraphQL.Schema as Schema
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execute :: (Alternative m, Monad m) => Schema m -> Document -> m Aeson.Value
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execute (Schema resolv) doc = selectionSet resolv =<< query doc
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query :: Alternative f => Document -> f SelectionSet
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query (Document [DefinitionOperation (Query (Node _ _ _ sels))]) = pure sels
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query _ = empty
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selectionSet :: Alternative f => Resolver f -> SelectionSet -> f Aeson.Value
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selectionSet resolv = fmap (Aeson.Object . fold) . traverse (selection resolv)
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selection :: Alternative f => Resolver f -> Selection -> f Aeson.Object
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selection resolv (SelectionField field@(Field _ name _ _ _)) =
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fmap (HashMap.singleton name) $ Aeson.toJSON <$> resolv (fieldToInput field)
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selection _ _ = empty
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-- * AST/Schema conversions
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argument :: Argument -> Schema.Argument
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argument (Argument n (ValueInt v)) = (n, Schema.ScalarInt $ fromIntegral v)
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argument (Argument n (ValueString (StringValue v))) = (n, Schema.ScalarString v)
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argument _ = error "argument: not implemented yet"
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fieldToInput :: Field -> Schema.Input
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fieldToInput (Field _ n as _ sels) =
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Schema.InputField n (argument <$> as) (fieldToInput . selectionToField <$> sels)
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selectionToField :: Selection -> Field
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selectionToField (SelectionField x) = x
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selectionToField _ = error "selectionField: not implemented yet"
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