blob: 8933d5bfe4c2608ba816de4ff26f3afe7e64b6e3 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
--------------------------------------------------------------------------------
-- | An item is a combination of some content and its 'Identifier'. This way, we
-- can still use the 'Identifier' to access metadata.
{-# LANGUAGE DeriveDataTypeable #-}
module Hakyll.Core.Item
( Item (..)
, itemSetBody
, withItemBody
) where
--------------------------------------------------------------------------------
import Control.Applicative (Applicative, (<$>), (<*>))
import Data.Binary (Binary (..))
import Data.Foldable (Foldable (..))
import Data.Traversable (Traversable (..))
import Data.Typeable (Typeable)
import Prelude hiding (foldr)
--------------------------------------------------------------------------------
import Hakyll.Core.Compiler.Internal
import Hakyll.Core.Identifier
--------------------------------------------------------------------------------
data Item a = Item
{ itemIdentifier :: Identifier
, itemBody :: a
} deriving (Show, Typeable)
--------------------------------------------------------------------------------
instance Functor Item where
fmap f (Item i x) = Item i (f x)
--------------------------------------------------------------------------------
instance Foldable Item where
foldr f z (Item _ x) = f x z
--------------------------------------------------------------------------------
instance Traversable Item where
traverse f (Item i x) = Item i <$> f x
--------------------------------------------------------------------------------
instance Binary a => Binary (Item a) where
put (Item i x) = put i >> put x
get = Item <$> get <*> get
--------------------------------------------------------------------------------
itemSetBody :: a -> Item b -> Item a
itemSetBody x (Item i _) = Item i x
--------------------------------------------------------------------------------
-- | 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
|
