{-# LANGUAGE Arrows #-}
module Opaleye.Label (
label',
label
) where
import qualified Opaleye.Internal.PrimQuery as PQ
import qualified Opaleye.Internal.QueryArr as Q
import qualified Opaleye.Select as S
import Control.Arrow (returnA)
label' :: String -> S.Select ()
label' :: String -> Select ()
label' String
l = (() -> State Tag ((), PrimQueryArr)) -> Select ()
forall a b. (a -> State Tag (b, PrimQueryArr)) -> SelectArr a b
Q.QueryArr () -> State Tag ((), PrimQueryArr)
forall (f :: * -> *). Applicative f => () -> f ((), PrimQueryArr)
f where
f :: () -> f ((), PrimQueryArr)
f () = ((), PrimQueryArr) -> f ((), PrimQueryArr)
forall (f :: * -> *) a. Applicative f => a -> f a
pure ((), String -> PrimQueryArr
PQ.aLabel String
l)
label :: String -> S.SelectArr a b -> S.SelectArr a b
label :: String -> SelectArr a b -> SelectArr a b
label String
l SelectArr a b
s = proc a
a -> do
b
b <- SelectArr a b
s -< a
a
String -> Select ()
label' String
l -< ()
SelectArr b b
forall (a :: * -> * -> *) b. Arrow a => a b b
returnA -< b
b