diff options
Diffstat (limited to 'src/Hakyll/Core/Item.hs')
| -rw-r--r-- | src/Hakyll/Core/Item.hs | 30 |
1 files changed, 24 insertions, 6 deletions
diff --git a/src/Hakyll/Core/Item.hs b/src/Hakyll/Core/Item.hs index ccf9e9a..8933d5b 100644 --- a/src/Hakyll/Core/Item.hs +++ b/src/Hakyll/Core/Item.hs @@ -5,17 +5,21 @@ module Hakyll.Core.Item ( Item (..) , itemSetBody - , itemM + , withItemBody ) where -------------------------------------------------------------------------------- -import Control.Applicative ((<$>), (<*>)) -import Data.Binary (Binary (..)) -import Data.Typeable (Typeable) +import Control.Applicative (Applicative, (<$>), (<*>)) +import Data.Binary (Binary (..)) +import Data.Foldable (Foldable (..)) +import Data.Traversable (Traversable (..)) +import Data.Typeable (Typeable) +import Prelude hiding (foldr) -------------------------------------------------------------------------------- +import Hakyll.Core.Compiler.Internal import Hakyll.Core.Identifier @@ -32,6 +36,16 @@ instance Functor Item where -------------------------------------------------------------------------------- +instance Foldable Item where + foldr f z (Item _ x) = f x z + + +-------------------------------------------------------------------------------- +instance Traversable Item where + traverse f (Item i x) = Item i <$> f x + + +-------------------------------------------------------------------------------- instance Binary a => Binary (Item a) where put (Item i x) = put i >> put x get = Item <$> get <*> get @@ -43,5 +57,9 @@ itemSetBody x (Item i _) = Item i x -------------------------------------------------------------------------------- -itemM :: Monad m => (a -> m b) -> Item a -> m (Item b) -itemM f (Item i b) = f b >>= \b' -> return (Item i b') +-- | Perform a compiler action on the item body. This is the same as 'traverse', +-- but looks less intimidating. +-- +-- > withItemBody = traverse +withItemBody :: (a -> Compiler b) -> Item a -> Compiler (Item b) +withItemBody = traverse |