102d07f · typeable/aeson

git.iko.soy/typeable/aeson

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Add Missing Value for non-present values.

102d07fJeremy Fitzhardinge16 years ago

Data/Aeson.hs+1

compare with master

unifiedsplit

@@ -24,6 +24,7 @@ module Data.Aeson

24 , ToJSON(..)

25 -- * Constructors and accessors

26 , (.=)

27+ , (.=?)

27 , (.:)

28 , (.:)

28 , (.:?)

29 , (.:?)

29 , object

30 , object

Data/Aeson/Encode.hs+1

@@ -29,6 +29,7 @@ import qualified Data.Vector as V

29-- | Encode a JSON value to a 'Builder'.

30fromValue :: Value -> Builder

31fromValue Null = fromByteString "null"

32+fromValue Missing = error "Unexpected Missing"

32fromValue (Bool b) = fromByteString $ if b then "true" else "false"

33fromValue (Bool b) = fromByteString $ if b then "true" else "false"

33fromValue (Number n) = fromByteString (B.pack (show n))

34fromValue (Number n) = fromByteString (B.pack (show n))

34fromValue (String s) = string s

35fromValue (String s) = string s

Data/Aeson/Types.hs+14−1

@@ -30,6 +30,7 @@ module Data.Aeson.Types

30 , ToJSON(..)

31 -- * Constructors and accessors

32 , (.=)

33+ , (.=?)

33 , (.:)

34 , (.:)

34 , (.:?)

35 , (.:?)

35 , object

36 , object

@@ -140,6 +141,7 @@ data Value = Object Object

140 | Number Number

141 | Number Number

141 | Bool !Bool

142 | Bool !Bool

142 | Null

143 | Null

144+ | Missing

143 deriving (Eq, Show, Typeable, Data)

145 deriving (Eq, Show, Typeable, Data)

144

146

145instance NFData Value where

147instance NFData Value where

@@ -149,6 +151,7 @@ instance NFData Value where

149 rnf (Number n) = case n of I i -> rnf i; D d -> rnf d

151 rnf (Number n) = case n of I i -> rnf i; D d -> rnf d

150 rnf (Bool b) = rnf b

152 rnf (Bool b) = rnf b

151 rnf Null = ()

153 rnf Null = ()

154+ rnf Missing = ()

152

155

153-- | The empty array.

156-- | The empty array.

154emptyArray :: Value

157emptyArray :: Value

@@ -166,6 +169,14 @@ type Pair = (Text, Value)

166name .= value = (name, toJSON value)

169name .= value = (name, toJSON value)

167{-# INLINE (.=) #-}

170{-# INLINE (.=) #-}

168

171

172+-- | Construct an optional 'Pair' from a key and a Maybe value. If

173+-- the value is Nothing, then it is omitted altogether from the

174+-- resulting Object.

175+(.=?) :: ToJSON a => Text -> Maybe a -> Pair

176+name .=? Nothing = (name, Missing)

177+name .=? Just value = (name, toJSON value)

178+{-# INLINE (.=?) #-}

179+

169-- | Convert a value from JSON, failing if the types do not match.

180-- | Convert a value from JSON, failing if the types do not match.

170fromJSON :: (FromJSON a) => Value -> Result a

181fromJSON :: (FromJSON a) => Value -> Result a

171fromJSON = parse parseJSON

182fromJSON = parse parseJSON

@@ -205,7 +216,9 @@ obj .:? key = case M.lookup key obj of

205-- | Create a 'Value' from a list of name\/value 'Pair's. If duplicate

216-- | Create a 'Value' from a list of name\/value 'Pair's. If duplicate

206-- keys arise, earlier keys and their associated values win.

217-- keys arise, earlier keys and their associated values win.

207object :: [Pair] -> Value

218object :: [Pair] -> Value

208−object = Object . M.fromList

219+object = Object . M.fromList . filter (notmissing . snd)

220+ where notmissing Missing = False

221+ notmissing _ = True

209{-# INLINE object #-}

222{-# INLINE object #-}

210

223

211-- | A type that can be converted to JSON.

224-- | A type that can be converted to JSON.