Safe Haskell	Safe-Inferred
Language	Haskell2010

Database.Persist.Compatible

Synopsis

newtype Compatible b s = Compatible {
- unCompatible :: s
}
makeCompatibleInstances :: Q Type -> Q [Dec]
makeCompatibleKeyInstances :: Q Type -> Q [Dec]

Documentation

newtype Compatible b s Source #

A newtype wrapper for compatible backends, mainly useful for DerivingVia.

When writing a new backend that is BackendCompatible with an existing backend, instances for the new backend can be naturally defined in terms of the instances for the existing backend.

For example, if you decide to augment the SqlBackend with some additional features:

data BetterSqlBackend = BetterSqlBackend { sqlBackend :: SqlBackend, ... }

instance BackendCompatible SqlBackend BetterSqlBackend where
  projectBackend = sqlBackend

Then you can use DerivingVia to automatically get instances like:

deriving via (Compatible SqlBackend BetterSqlBackend) instance PersistStoreRead BetterSqlBackend
deriving via (Compatible SqlBackend BetterSqlBackend) instance PersistStoreWrite BetterSqlBackend
...

These instances will go through the compatible backend (in this case, SqlBackend) for all their queries.

These instances require that both backends have the same BaseBackend, but deriving HasPersistBackend will enforce that for you.

deriving via (Compatible SqlBackend BetterSqlBackend) instance HasPersistBackend BetterSqlBackend

Since: 2.12

Constructors

Compatible
Fields unCompatible :: s

Instances

Instances details

(BackendCompatible b s, FromJSON (BackendKey b)) => FromJSON (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods parseJSON :: Value -> Parser (BackendKey (Compatible b s)) # parseJSONList :: Value -> Parser [BackendKey (Compatible b s)] #
(BackendCompatible b s, ToJSON (BackendKey b)) => ToJSON (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods toJSON :: BackendKey (Compatible b s) -> Value # toEncoding :: BackendKey (Compatible b s) -> Encoding # toJSONList :: [BackendKey (Compatible b s)] -> Value # toEncodingList :: [BackendKey (Compatible b s)] -> Encoding #
(BackendCompatible b s, Bounded (BackendKey b)) => Bounded (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods minBound :: BackendKey (Compatible b s) # maxBound :: BackendKey (Compatible b s) #
(BackendCompatible b s, Enum (BackendKey b)) => Enum (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods succ :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) # pred :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) # toEnum :: Int -> BackendKey (Compatible b s) # fromEnum :: BackendKey (Compatible b s) -> Int # enumFrom :: BackendKey (Compatible b s) -> [BackendKey (Compatible b s)] # enumFromThen :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> [BackendKey (Compatible b s)] # enumFromTo :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> [BackendKey (Compatible b s)] # enumFromThenTo :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> [BackendKey (Compatible b s)] #
(BackendCompatible b s, Num (BackendKey b)) => Num (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods (+) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # (-) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # (*) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # negate :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) # abs :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) # signum :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) # fromInteger :: Integer -> BackendKey (Compatible b s) #
(BackendCompatible b s, Read (BackendKey b)) => Read (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods readsPrec :: Int -> ReadS (BackendKey (Compatible b s)) # readList :: ReadS [BackendKey (Compatible b s)] # readPrec :: ReadPrec (BackendKey (Compatible b s)) # readListPrec :: ReadPrec [BackendKey (Compatible b s)] #
(BackendCompatible b s, Integral (BackendKey b)) => Integral (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods quot :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # rem :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # div :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # mod :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # quotRem :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> (BackendKey (Compatible b s), BackendKey (Compatible b s)) # divMod :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> (BackendKey (Compatible b s), BackendKey (Compatible b s)) # toInteger :: BackendKey (Compatible b s) -> Integer #
(BackendCompatible b s, Real (BackendKey b)) => Real (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods toRational :: BackendKey (Compatible b s) -> Rational #
(BackendCompatible b s, Show (BackendKey b)) => Show (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods showsPrec :: Int -> BackendKey (Compatible b s) -> ShowS # show :: BackendKey (Compatible b s) -> String # showList :: [BackendKey (Compatible b s)] -> ShowS #
(BackendCompatible b s, Eq (BackendKey b)) => Eq (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods (==) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> Bool # (/=) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> Bool #
(BackendCompatible b s, Ord (BackendKey b)) => Ord (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods compare :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> Ordering # (<) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> Bool # (<=) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> Bool # (>) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> Bool # (>=) :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> Bool # max :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) # min :: BackendKey (Compatible b s) -> BackendKey (Compatible b s) -> BackendKey (Compatible b s) #
(BackendCompatible b s, PersistField (BackendKey b)) => PersistField (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods toPersistValue :: BackendKey (Compatible b s) -> PersistValue Source # fromPersistValue :: PersistValue -> Either Text (BackendKey (Compatible b s)) Source #
(BackendCompatible b s, PersistFieldSql (BackendKey b)) => PersistFieldSql (BackendKey (Compatible b s)) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods sqlType :: Proxy (BackendKey (Compatible b s)) -> SqlType Source #
(HasPersistBackend b, BackendCompatible b s, PersistQueryRead b) => PersistQueryRead (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods selectSourceRes :: forall record (m1 :: Type -> Type) (m2 :: Type -> Type). (PersistRecordBackend record (Compatible b s), MonadIO m1, MonadIO m2) => [Filter record] -> [SelectOpt record] -> ReaderT (Compatible b s) m1 (Acquire (ConduitM () (Entity record) m2 ())) Source # selectFirst :: forall (m :: Type -> Type) record. (MonadIO m, PersistRecordBackend record (Compatible b s)) => [Filter record] -> [SelectOpt record] -> ReaderT (Compatible b s) m (Maybe (Entity record)) Source # selectKeysRes :: forall (m1 :: Type -> Type) (m2 :: Type -> Type) record. (MonadIO m1, MonadIO m2, PersistRecordBackend record (Compatible b s)) => [Filter record] -> [SelectOpt record] -> ReaderT (Compatible b s) m1 (Acquire (ConduitM () (Key record) m2 ())) Source # count :: forall (m :: Type -> Type) record. (MonadIO m, PersistRecordBackend record (Compatible b s)) => [Filter record] -> ReaderT (Compatible b s) m Int Source # exists :: forall (m :: Type -> Type) record. (MonadIO m, PersistRecordBackend record (Compatible b s)) => [Filter record] -> ReaderT (Compatible b s) m Bool Source #
(HasPersistBackend b, BackendCompatible b s, PersistQueryWrite b) => PersistQueryWrite (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods updateWhere :: forall (m :: Type -> Type) record. (MonadIO m, PersistRecordBackend record (Compatible b s)) => [Filter record] -> [Update record] -> ReaderT (Compatible b s) m () Source # deleteWhere :: forall (m :: Type -> Type) record. (MonadIO m, PersistRecordBackend record (Compatible b s)) => [Filter record] -> ReaderT (Compatible b s) m () Source #
(BackendCompatible b s, HasPersistBackend b) => HasPersistBackend (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Associated Types type BaseBackend (Compatible b s) Source # Methods persistBackend :: Compatible b s -> BaseBackend (Compatible b s) Source #
(BackendCompatible b s, PersistCore b) => PersistCore (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Associated Types data BackendKey (Compatible b s) Source #
(HasPersistBackend b, BackendCompatible b s, PersistStoreRead b) => PersistStoreRead (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods get :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Key record -> ReaderT (Compatible b s) m (Maybe record) Source # getMany :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => [Key record] -> ReaderT (Compatible b s) m (Map (Key record) record) Source #
(HasPersistBackend b, BackendCompatible b s, PersistStoreWrite b) => PersistStoreWrite (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods insert :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => record -> ReaderT (Compatible b s) m (Key record) Source # insert_ :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => record -> ReaderT (Compatible b s) m () Source # insertMany :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => [record] -> ReaderT (Compatible b s) m [Key record] Source # insertMany_ :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => [record] -> ReaderT (Compatible b s) m () Source # insertEntityMany :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => [Entity record] -> ReaderT (Compatible b s) m () Source # insertKey :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Key record -> record -> ReaderT (Compatible b s) m () Source # repsert :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Key record -> record -> ReaderT (Compatible b s) m () Source # repsertMany :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => [(Key record, record)] -> ReaderT (Compatible b s) m () Source # replace :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Key record -> record -> ReaderT (Compatible b s) m () Source # delete :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Key record -> ReaderT (Compatible b s) m () Source # update :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Key record -> [Update record] -> ReaderT (Compatible b s) m () Source # updateGet :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Key record -> [Update record] -> ReaderT (Compatible b s) m record Source #
(HasPersistBackend b, BackendCompatible b s, PersistUniqueRead b) => PersistUniqueRead (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods getBy :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Unique record -> ReaderT (Compatible b s) m (Maybe (Entity record)) Source # existsBy :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Unique record -> ReaderT (Compatible b s) m Bool Source #
(HasPersistBackend b, BackendCompatible b s, PersistUniqueWrite b) => PersistUniqueWrite (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types Methods deleteBy :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s)) => Unique record -> ReaderT (Compatible b s) m () Source # insertUnique :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => record -> ReaderT (Compatible b s) m (Maybe (Key record)) Source # insertUnique_ :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => record -> ReaderT (Compatible b s) m (Maybe ()) Source # upsert :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), OnlyOneUniqueKey record, SafeToInsert record) => record -> [Update record] -> ReaderT (Compatible b s) m (Entity record) Source # upsertBy :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => Unique record -> record -> [Update record] -> ReaderT (Compatible b s) m (Entity record) Source # putMany :: forall record (m :: Type -> Type). (MonadIO m, PersistRecordBackend record (Compatible b s), SafeToInsert record) => [record] -> ReaderT (Compatible b s) m () Source #
newtype BackendKey (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types newtype BackendKey (Compatible b s) = CompatibleKey { unCompatibleKey :: BackendKey b }
type BaseBackend (Compatible b s) Source #
Instance details Defined in Database.Persist.Compatible.Types type BaseBackend (Compatible b s) = BaseBackend b

makeCompatibleInstances :: Q Type -> Q [Dec] Source #

Gives a bunch of useful instance declarations for a backend based on its compatibility with another backend, using Compatible.

The argument should be a type of the form forall v1 ... vn. Compatible b s (Quantification is optional, but supported because TH won't let you have unbound type variables in a type splice). The instance is produced for s based on the instance defined for b, which is constrained in the instance head to exist.

v1 ... vn are implicitly quantified in the instance, which is derived via Compatible b s.

Since: 2.12

makeCompatibleKeyInstances :: Q Type -> Q [Dec] Source #

Gives a bunch of useful instance declarations for a backend key based on its compatibility with another backend & key, using Compatible.

The argument should be a type of the form forall v1 ... vn. Compatible b s (Quantification is optional, but supported because TH won't let you have unbound type variables in a type splice). The instance is produced for BackendKey s based on the instance defined for BackendKey b, which is constrained in the instance head to exist.

v1 ... vn are implicitly quantified in the instance, which is derived via BackendKey (Compatible b s).

Since: 2.12