blob: 1f521ccbeef9a41131185a815debd80fc7a16641 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
|
-- | Instances for the Data.UUID UUID type to be mapped to postgresql's
-- custom builtin uuid type.
--
-- Unfortunately, this breaks compatability with other SQL databases
-- (though uuids aren't really supported by most anyways)
module PersistOrphans () where
import Data.Either.Combinators (maybeToRight)
import qualified Data.Text as T
import Data.UUID (UUID)
import Data.UUID as UUID
import Data.UUID.V4
import Database.Persist (PersistField (..),
PersistValue (PersistLiteralEscaped),
SqlType (SqlOther))
import Database.Persist.Sql (PersistFieldSql (..), SqlBackend,
migrate, runMigration)
import Web.PathPieces (PathPiece (..))
instance PersistField UUID where
toPersistValue = PersistLiteralEscaped . UUID.toASCIIBytes
fromPersistValue (PersistLiteralEscaped buf) =
maybeToRight "not a uuid (cannot decode)" $ UUID.fromASCIIBytes buf
fromPersistValue v = Left $ "not a uuid (wrong type in database): " <> T.pack (show v)
-- postgres is type-safe, so this should /hopefully/ never happen
instance PersistFieldSql UUID where
sqlType = const $ SqlOther "uuid"
instance PathPiece UUID where
fromPathPiece = UUID.fromText
toPathPiece = UUID.toText
|
