graphql.elm

userByEmail : UserByEmailRequiredArguments -> SelectionSet decodesTo Schema.Object.User -> Field (Maybe decodesTo) RootQuery
userByEmail requiredArgs object =
    Object.selectionField "userByEmail" [ Argument.required "email" requiredArgs.email Encode.string ] object (identity >> Decode.nullable)

type alias EmailQueryResponse =
  { email : Maybe Email }

type alias Email =
  { email: String }

query : SelectionSet EmailQueryResponse RootQuery
query =
  let
    q = Query.selection EmailQueryResponse |> with (Query.userByEmail { email = "ngw@test.org" } user)
  in
    Debug.log "Q" q

user : SelectionSet Email Schema.Object.User
user =
  Schema.Object.User.selection Email
    |> with Schema.Object.User.email