Levels and Privileges sketch

library/HighSQL.hs

@@ -2,6 +2,7 @@ module HighSQL where
 
 import HighSQL.Prelude hiding (read, Read, write, Write)
 import qualified HighSQL.Backend as Backend
+import qualified HighSQL.CompositionT as CompositionT
 import qualified Data.Pool as Pool
 
 
@@ -16,3 +17,58 @@ type S =
 session :: Backend.Backend -> S m r -> m r
 session b s =
   $notImplemented
+
+
+-- * Transactions
+-------------------------
+
+-- |
+-- A transaction with a level @l@ and a result @r@.
+data T l r
+
+
+-- ** Privileges
+-------------------------
+
+class SelectPrivilege l
+
+select :: SelectPrivilege l => Select r -> T l r
+select = 
+  $notImplemented
+
+
+class UpdatePrivilege l
+
+update :: UpdatePrivilege l => Update -> T l ()
+update =
+  $notImplemented
+
+-- class AlterPrivilege p where
+--   alter :: Alter -> T p ()
+
+
+-- ** Levels
+-------------------------
+
+data Read
+
+instance SelectPrivilege Read
+
+
+data Write
+
+instance SelectPrivilege Write
+instance UpdatePrivilege Write
+
+data Admin
+
+
+-- * Statements
+-------------------------
+
+newtype Select r =
+  Select (Backend.Connection -> IO r)
+
+newtype Update =
+  Update (Backend.Connection -> IO ())
+