Add Graphql Core AST

Data/GraphQL/AST/Core.hs

@@ -0,0 +1,31 @@
+-- | This is the AST meant to be executed.
+module Data.GraphQL.AST.Core where
+
+import Data.Int (Int32)
+import Data.List.NonEmpty (NonEmpty)
+
+import Data.Text (Text)
+
+newtype Name = Name Text deriving (Eq,Show)
+
+newtype Document = Document (NonEmpty Operation) deriving (Eq,Show)
+
+data Operation = Query (NonEmpty Field)
+               | Mutation (NonEmpty Field)
+                 deriving (Eq,Show)
+
+data Field = Field Name [Argument] [Field] deriving (Eq,Show)
+
+data Argument = Argument Name Value deriving (Eq,Show)
+
+data Value = ValueInt Int32
+           -- GraphQL Float is double precision
+           | ValueFloat Double
+           | ValueBoolean Bool
+           | ValueString Text
+           | ValueEnum Name
+           | ValueList [Value]
+           | ValueObject [ObjectField]
+             deriving (Eq,Show)
+
+data ObjectField = ObjectField Name Value deriving (Eq,Show)