Define applicative instance for Value

2018-06-22 19:54:18 +01:00 · 2018-06-22 19:54:18 +01:00 · 457d6caccd
commit 457d6caccd
parent b81e0d951e
1 changed files with 3 additions and 0 deletions
--- a/src/Database/Esqueleto/Internal/Language.hs
+++ b/src/Database/Esqueleto/Internal/Language.hs
@ -630,6 +630,9 @@ newtype Value a = Value { unValue :: a } deriving (Eq, Ord, Show, Typeable)
 instance Functor Value where
  fmap f (Value a) = Value (f a)

+instance Applicative Value where
+  (<*>) (Value f) (Value a) = Value (f a)
+  pure = Value

 -- | A list of single values.  There's a limited set of functions
 -- able to work with this data type (such as 'subList_select',