@@ -161,6 +161,8 @@ import Squeal.PostgreSQL
161import System.Environment
161import System.Environment
163-- | A `Migration` is a named "isomorphism" over a given category.
163-- | A `Migration` is a named "isomorphism" over a given category.
164+-- It should contain an inverse pair of `up` and `down`
165+-- instructions and a unique `name`.
164data Migration p schemas0 schemas1 = Migration
166data Migration p schemas0 schemas1 = Migration
165 { name :: Text -- ^ The `name` of a `Migration`.
167 { name :: Text -- ^ The `name` of a `Migration`.
166 -- Each `name` in a `Migration` should be unique.
168 -- Each `name` in a `Migration` should be unique.