@@ -2,6 +2,8 @@ module Squeal.PostgreSQL.Migration where
3import Squeal.PostgreSQL.PQ
3import Squeal.PostgreSQL.PQ
5+-- | A `Migration` is in the isomorphism subcategory
6+-- of the indexed monad `PQ`
5data Migration schema0 schema1 m x = Migration
7data Migration schema0 schema1 m x = Migration
6 { migrateUp :: PQ schema0 schema1 m x
8 { migrateUp :: PQ schema0 schema1 m x
7 , migrateDown :: PQ schema0 schema1 m x
9 , migrateDown :: PQ schema0 schema1 m x