693b7d18dc
In the Transform module the Full AST will converted to Core AST. This commit also includes a partial implementation of Fragment replacement.
87 lines
3.0 KiB
Haskell
87 lines
3.0 KiB
Haskell
module Data.GraphQL.AST.Transform where
|
|
|
|
import Control.Applicative (empty)
|
|
import Data.Bifunctor (first)
|
|
import Data.Either (partitionEithers)
|
|
import qualified Data.List.NonEmpty as NonEmpty
|
|
-- import Data.List.NonEmpty (NonEmpty((:|)))
|
|
import Data.Monoid (Alt(Alt,getAlt))
|
|
import Data.Foldable (foldMap)
|
|
|
|
import Data.Text (Text)
|
|
|
|
import qualified Data.GraphQL.AST as Full
|
|
import qualified Data.GraphQL.AST.Core as Core
|
|
import qualified Data.GraphQL.Schema as Schema
|
|
|
|
type Name = Text
|
|
|
|
-- | Replaces a fragment name by a list of 'Field'. If the name doesn't match an
|
|
-- empty list is returned.
|
|
type Fragmenter = Name -> [Core.Field]
|
|
|
|
document :: Schema.Subs -> Full.Document -> Core.Document
|
|
document subs defs = operations subs fr ops
|
|
where
|
|
(fr, ops) = first foldFrags . partitionEithers . NonEmpty.toList $ defrag <$> defs
|
|
|
|
foldFrags :: [Fragmenter] -> Fragmenter
|
|
foldFrags fs n = getAlt $ foldMap (Alt . ($ n)) fs
|
|
|
|
-- * Fragment replacement
|
|
|
|
-- | Extract Fragments into a single Fragmenter function and a Operation
|
|
-- Definition.
|
|
defrag :: Full.Definition -> Either Fragmenter Full.OperationDefinition
|
|
defrag (Full.DefinitionOperation op) = Right op
|
|
defrag (Full.DefinitionFragment fragDef) = Left $ fragmentDefinition fragDef
|
|
|
|
fragmentDefinition :: Full.FragmentDefinition -> Fragmenter
|
|
fragmentDefinition (Full.FragmentDefinition name _tc _dirs sels) name' =
|
|
if name == name' then NonEmpty.toList (selection <$> sels) else empty
|
|
|
|
selection :: Full.Selection -> Core.Field
|
|
selection (Full.SelectionField _fld) = field _fld
|
|
selection (Full.SelectionFragmentSpread _) = error "Nested fragments not supported yet"
|
|
selection (Full.SelectionInlineFragment _) =
|
|
error "Inline fragments within fragments not supported yet"
|
|
|
|
field :: Full.Field -> Core.Field
|
|
field (Full.Field a n args _ sels) =
|
|
Core.Field a n (argument <$> args) (selection <$> sels)
|
|
|
|
argument :: Full.Argument -> Core.Argument
|
|
argument (Full.Argument n v) = Core.Argument n (value v)
|
|
|
|
value :: Full.Value -> Core.Value
|
|
value (Full.ValueVariable _) = error "Variables within fragments not supported yet"
|
|
value (Full.ValueInt i) = Core.ValueInt i
|
|
value (Full.ValueFloat f) = Core.ValueFloat f
|
|
value (Full.ValueString x) = Core.ValueString x
|
|
value (Full.ValueBoolean b) = Core.ValueBoolean b
|
|
value Full.ValueNull = Core.ValueNull
|
|
value (Full.ValueEnum e) = Core.ValueEnum e
|
|
value (Full.ValueList l) = Core.ValueList (value <$> l)
|
|
value (Full.ValueObject o) = Core.ValueObject (objectField <$> o)
|
|
|
|
objectField :: Full.ObjectField -> Core.ObjectField
|
|
objectField (Full.ObjectField n v) = Core.ObjectField n (value v)
|
|
|
|
-- * Operation
|
|
|
|
operations
|
|
:: Schema.Subs
|
|
-> Fragmenter
|
|
-> [Full.OperationDefinition]
|
|
-> Core.Document
|
|
-- XXX: Replace `fromList` by proper error: at least a Query or Mutation
|
|
-- operation must be present
|
|
operations subs fr = NonEmpty.fromList . fmap (operation subs fr)
|
|
|
|
operation
|
|
:: Schema.Subs
|
|
-> Fragmenter
|
|
-> Full.OperationDefinition
|
|
-> Core.Operation
|
|
operation _subs _fr _op = undefined
|