Safe Haskell	None
Language	Haskell2010

Opaleye.SQLite.Internal.Aggregate

Synopsis

newtype Aggregator a b = Aggregator (PackMap (Maybe AggrOp, PrimExpr) PrimExpr a b)
makeAggr' :: Maybe AggrOp -> Aggregator (Column a) (Column b)
makeAggr :: AggrOp -> Aggregator (Column a) (Column b)
runAggregator :: Applicative f => Aggregator a b -> ((Maybe AggrOp, PrimExpr) -> f PrimExpr) -> a -> f b
aggregateU :: Aggregator a b -> (a, PrimQuery, Tag) -> (b, PrimQuery, Tag)
extractAggregateFields :: Tag -> (Maybe AggrOp, PrimExpr) -> PM [(Symbol, (Maybe AggrOp, PrimExpr))] PrimExpr

Documentation

newtype Aggregator a b Source #

An Aggregator takes a collection of rows of type a, groups them, and transforms each group into a single row of type b. This corresponds to aggregators using GROUP BY in SQL.

An Aggregator corresponds closely to a Fold from the foldl package. Whereas an Aggregator a b takes each group of type a to a single row of type b, a Fold a b takes a list of a and returns a single row of type b.

Constructors

Aggregator (PackMap (Maybe AggrOp, PrimExpr) PrimExpr a b)

Instances

Instances details

Profunctor Aggregator Source #
Instance details Defined in Opaleye.SQLite.Internal.Aggregate Methods dimap :: (a -> b) -> (c -> d) -> Aggregator b c -> Aggregator a d # lmap :: (a -> b) -> Aggregator b c -> Aggregator a c # rmap :: (b -> c) -> Aggregator a b -> Aggregator a c # (#.) :: forall a b c q. Coercible c b => q b c -> Aggregator a b -> Aggregator a c # (.#) :: forall a b c q. Coercible b a => Aggregator b c -> q a b -> Aggregator a c #
ProductProfunctor Aggregator Source #
Instance details Defined in Opaleye.SQLite.Internal.Aggregate Methods purePP :: b -> Aggregator a b # (**) :: Aggregator a (b -> c) -> Aggregator a b -> Aggregator a c # empty :: Aggregator () () # (*!) :: Aggregator a b -> Aggregator a' b' -> Aggregator (a, a') (b, b') #
SumProfunctor Aggregator Source #
Instance details Defined in Opaleye.SQLite.Internal.Aggregate Methods (+++!) :: Aggregator a b -> Aggregator a' b' -> Aggregator (Either a a') (Either b b') #
Functor (Aggregator a) Source #
Instance details Defined in Opaleye.SQLite.Internal.Aggregate Methods fmap :: (a0 -> b) -> Aggregator a a0 -> Aggregator a b # (<$) :: a0 -> Aggregator a b -> Aggregator a a0 #
Applicative (Aggregator a) Source #
Instance details Defined in Opaleye.SQLite.Internal.Aggregate Methods pure :: a0 -> Aggregator a a0 # (<>) :: Aggregator a (a0 -> b) -> Aggregator a a0 -> Aggregator a b # liftA2 :: (a0 -> b -> c) -> Aggregator a a0 -> Aggregator a b -> Aggregator a c # (>) :: Aggregator a a0 -> Aggregator a b -> Aggregator a b # (<*) :: Aggregator a a0 -> Aggregator a b -> Aggregator a a0 #

makeAggr' :: Maybe AggrOp -> Aggregator (Column a) (Column b) Source #

makeAggr :: AggrOp -> Aggregator (Column a) (Column b) Source #

runAggregator :: Applicative f => Aggregator a b -> ((Maybe AggrOp, PrimExpr) -> f PrimExpr) -> a -> f b Source #

aggregateU :: Aggregator a b -> (a, PrimQuery, Tag) -> (b, PrimQuery, Tag) Source #

extractAggregateFields :: Tag -> (Maybe AggrOp, PrimExpr) -> PM [(Symbol, (Maybe AggrOp, PrimExpr))] PrimExpr Source #