Move Transform to Language.GraphQL.Execute

Language.GraphQL.AST.Transform is an internal module. Even though it
works with the AST, it is a part of the execution process, it translates
the original parser tree into a simpler one, so the executor has less
work to do. Language.GraphQL.AST should contain only the parser and be
independent from other packages, so it can be used on its own.

package.yaml

@@ -37,7 +37,7 @@ dependencies:
 library:
   source-dirs: src
   other-modules:
-    - Language.GraphQL.AST.Transform
+    - Language.GraphQL.Execute.Transform
     - Language.GraphQL.Execute.Directive
 
 tests:

src/Language/GraphQL/Execute.hs

@@ -15,7 +15,7 @@ import Data.Text (Text)
 import qualified Data.Text as Text
 import qualified Language.GraphQL.AST as AST
 import qualified Language.GraphQL.AST.Core as AST.Core
-import qualified Language.GraphQL.AST.Transform as Transform
+import qualified Language.GraphQL.Execute.Transform as Transform
 import Language.GraphQL.Error
 import qualified Language.GraphQL.Schema as Schema
 

src/Language/GraphQL/Execute/Transform.hs

@@ -4,7 +4,7 @@
 -- | After the document is parsed, before getting executed the AST is
 --   transformed into a similar, simpler AST. This module is responsible for
 --   this transformation.
-module Language.GraphQL.AST.Transform
+module Language.GraphQL.Execute.Transform
     ( document
     ) where
 
@@ -30,6 +30,9 @@ data Replacement = Replacement
 
 type TransformT a = StateT Replacement (ReaderT Schema.Subs Maybe) a
 
+liftJust :: forall a. a -> TransformT a
+liftJust = lift . lift . Just
+
 -- | Rewrites the original syntax tree into an intermediate representation used
 -- for query execution.
 document :: Schema.Subs -> Full.Document -> Maybe Core.Document
@@ -179,6 +182,3 @@ value (Full.Object o) =
 
 objectField :: Full.ObjectField -> TransformT (Core.Name, Core.Value)
 objectField (Full.ObjectField name value') = (name,) <$> value value'
-
-liftJust :: forall a. a -> TransformT a
-liftJust = lift . lift . Just