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
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
|
--------------------------------------------------------------------------------
module Hakyll.Core.Metadata
( Metadata
, lookupString
, lookupStringList
, MonadMetadata (..)
, getMetadataField
, getMetadataField'
, makePatternDependency
, BinaryMetadata (..)
) where
--------------------------------------------------------------------------------
import Control.Arrow (second)
import Control.Monad (forM)
import Data.Binary (Binary (..), getWord8,
putWord8, Get)
import qualified Data.HashMap.Strict as HMS
import qualified Data.Set as S
import qualified Data.Text as T
import qualified Data.Vector as V
import qualified Data.Yaml.Extended as Yaml
import Hakyll.Core.Dependencies
import Hakyll.Core.Identifier
import Hakyll.Core.Identifier.Pattern
--------------------------------------------------------------------------------
type Metadata = Yaml.Object
--------------------------------------------------------------------------------
lookupString :: String -> Metadata -> Maybe String
lookupString key meta = HMS.lookup (T.pack key) meta >>= Yaml.toString
--------------------------------------------------------------------------------
lookupStringList :: String -> Metadata -> Maybe [String]
lookupStringList key meta =
HMS.lookup (T.pack key) meta >>= Yaml.toList >>= mapM Yaml.toString
--------------------------------------------------------------------------------
class Monad m => MonadMetadata m where
getMetadata :: Identifier -> m Metadata
getMatches :: Pattern -> m [Identifier]
getAllMetadata :: Pattern -> m [(Identifier, Metadata)]
getAllMetadata pattern = do
matches' <- getMatches pattern
forM matches' $ \id' -> do
metadata <- getMetadata id'
return (id', metadata)
--------------------------------------------------------------------------------
getMetadataField :: MonadMetadata m => Identifier -> String -> m (Maybe String)
getMetadataField identifier key = do
metadata <- getMetadata identifier
return $ lookupString key metadata
--------------------------------------------------------------------------------
-- | Version of 'getMetadataField' which throws an error if the field does not
-- exist.
getMetadataField' :: (MonadFail m, MonadMetadata m) => Identifier -> String -> m String
getMetadataField' identifier key = do
field <- getMetadataField identifier key
case field of
Just v -> return v
Nothing -> fail $ "Hakyll.Core.Metadata.getMetadataField': " ++
"Item " ++ show identifier ++ " has no metadata field " ++ show key
--------------------------------------------------------------------------------
makePatternDependency :: MonadMetadata m => Pattern -> m Dependency
makePatternDependency pattern = do
matches' <- getMatches pattern
return $ PatternDependency pattern (S.fromList matches')
--------------------------------------------------------------------------------
-- | Newtype wrapper for serialization.
newtype BinaryMetadata = BinaryMetadata
{unBinaryMetadata :: Metadata}
instance Binary BinaryMetadata where
put (BinaryMetadata obj) = put (BinaryYaml $ Yaml.Object obj)
get = do
BinaryYaml (Yaml.Object obj) <- get
return $ BinaryMetadata obj
--------------------------------------------------------------------------------
newtype BinaryYaml = BinaryYaml {unBinaryYaml :: Yaml.Value}
--------------------------------------------------------------------------------
instance Binary BinaryYaml where
put (BinaryYaml yaml) = case yaml of
Yaml.Object obj -> do
putWord8 0
let list :: [(T.Text, BinaryYaml)]
list = map (second BinaryYaml) $ HMS.toList obj
put list
Yaml.Array arr -> do
putWord8 1
let list = map BinaryYaml (V.toList arr) :: [BinaryYaml]
put list
Yaml.String s -> putWord8 2 >> put s
Yaml.Number n -> putWord8 3 >> put n
Yaml.Bool b -> putWord8 4 >> put b
Yaml.Null -> putWord8 5
get = do
tag <- getWord8
case tag of
0 -> do
list <- get :: Get [(T.Text, BinaryYaml)]
return $ BinaryYaml $ Yaml.Object $
HMS.fromList $ map (second unBinaryYaml) list
1 -> do
list <- get :: Get [BinaryYaml]
return $ BinaryYaml $
Yaml.Array $ V.fromList $ map unBinaryYaml list
2 -> BinaryYaml . Yaml.String <$> get
3 -> BinaryYaml . Yaml.Number <$> get
4 -> BinaryYaml . Yaml.Bool <$> get
5 -> return $ BinaryYaml Yaml.Null
_ -> fail "Data.Binary.get: Invalid Binary Metadata"
|
