921b759 · typeable/aeson

git.iko.soy/typeable/aeson

Add (.:!) and partially revert d0414be92ee6bf5b4c057978955b89d111767dab

commit921b75948d22aa8d6f8d2f82340742e011b3910e authorOleg Grenrus <oleg.grenrus@iki.fi> dateSat 19 Sep 2015, 17:20 (11 years ago) parent4667ef1

5 files changed+23−9

compare with master

unifiedsplit

Data/Aeson.hs+1 Data/Aeson/TH.hs+2−2 Data/Aeson/Types.hs+1 Data/Aeson/Types/Generic.hs+3−3 Data/Aeson/Types/Instances.hs+16−4

Data/Aeson.hs+1

@@ -78,6 +78,7 @@ module Data.Aeson

7878 , foldable

7979 , (.:)

8080 , (.:?)

81+ , (.:!)

8182 , (.!=)

8283 , object

8384 -- * Parsing

Data/Aeson/TH.hs+2−2

@@ -101,7 +101,7 @@ import Data.Aeson.Types ( Value(..), Parser

101101 , defaultTaggedObject

102102 )

103103import Data.Aeson.Types.Internal (Encoding(..))

104−import Control.Monad ( join, liftM2, return, mapM, fail )

104+import Control.Monad ( liftM2, return, mapM, fail )

105105import Data.Bool ( Bool(False, True), otherwise, (&&), not )

106106import Data.Either ( Either(Left, Right) )

107107import Data.Eq ( (==) )

@@ -960,7 +960,7 @@ instance OVERLAPPABLE_ (FromJSON a) => LookupField a where

960960 Just v -> parseJSON v

961961

962962instance (FromJSON a) => LookupField (Maybe a) where

963− lookupField _ _ obj key = join <$> obj .:? key

963+ lookupField _ _ = (.:?)

964964

965965unknownFieldFail :: String -> String -> String -> Parser fail

966966unknownFieldFail tName rec key =

Data/Aeson/Types.hs+1

@@ -55,6 +55,7 @@ module Data.Aeson.Types

5555 , foldable

5656 , (.:)

5757 , (.:?)

58+ , (.:!)

5859 , (.!=)

5960 , object

6061

Data/Aeson/Types/Generic.hs+3−3

@@ -22,7 +22,7 @@

2222module Data.Aeson.Types.Generic ( ) where

2323

2424import Control.Applicative ((<|>))

25−import Control.Monad ((<=<), join)

25+import Control.Monad ((<=<))

2626import Control.Monad.ST (ST)

2727import Data.Aeson.Encode.Builder (emptyArray_)

2828import Data.Aeson.Encode.Functions (builder)

@@ -665,8 +665,8 @@ instance (Selector s, GFromJSON a) => FromRecord (S1 s a) where

665665

666666instance OVERLAPPING_ (Selector s, FromJSON a) =>

667667 FromRecord (S1 s (K1 i (Maybe a))) where

668− parseRecord _ (Just lab) obj = (M1 . K1) . join <$> obj .:? lab

669− parseRecord opts Nothing obj = (M1 . K1) . join <$> obj .:? pack label

668+ parseRecord _ (Just lab) obj = (M1 . K1) <$> obj .:? lab

669+ parseRecord opts Nothing obj = (M1 . K1) <$> obj .:? pack label

670670 where

671671 label = fieldLabelModifier opts $

672672 selName (undefined :: t s (K1 i (Maybe a)) p)

Data/Aeson/Types/Instances.hs+16−4

@@ -52,6 +52,7 @@ module Data.Aeson.Types.Instances

5252 , ifromJSON

5353 , (.:)

5454 , (.:?)

55+ , (.:!)

5556 , (.!=)

5657 , tuple

5758 , (>*<)

@@ -1533,7 +1534,7 @@ ifromJSON = iparse parseJSON

15331534--

15341535-- This accessor is appropriate if the key and value /must/ be present

15351536-- in an object for it to be valid. If the key and value are

1536−-- optional, use '(.:?)' instead.

1537+-- optional, use '.:?' instead.

15371538(.:) :: (FromJSON a) => Object -> Text -> Parser a

15381539obj .: key = case H.lookup key obj of

15391540 Nothing -> fail $ "key " ++ show key ++ " not present"

@@ -1549,23 +1550,34 @@ obj .: key = case H.lookup key obj of

15491550--

15501551-- This accessor is most useful if the key and value can be absent

15511552-- from an object without affecting its validity. If the key and

1552−-- value are mandatory, use '(.:)' instead.

1553+-- value are mandatory, use '.:' instead.

15531554(.:?) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)

15541555obj .:? key = case H.lookup key obj of

15551556 Nothing -> pure Nothing

15561557 Just v -> modifyFailure addKeyName

1557− $ Just <$> parseJSON v <?> Key key

1558+ $ parseJSON v <?> Key key

15581559 where

15591560 addKeyName = (("failed to parse field " <> unpack key <> ": ") <>)

15601561{-# INLINE (.:?) #-}

15611562

1563+-- | Like '.:?', but the resulting parser will fail,

1564+-- if the key is present but is 'Null'.

1565+(.:!) :: (FromJSON a) => Object -> Text -> Parser (Maybe a)

1566+obj .:! key = case H.lookup key obj of

1567+ Nothing -> pure Nothing

1568+ Just v -> modifyFailure addKeyName

1569+ $ Just <$> parseJSON v <?> Key key

1570+ where

1571+ addKeyName = (("failed to parse field " <> unpack key <> ": ") <>)

1572+{-# INLINE (.:!) #-}

1573+

15621574-- | Helper for use in combination with '.:?' to provide default

15631575-- values for optional JSON object fields.

15641576--

15651577-- This combinator is most useful if the key and value can be absent

15661578-- from an object without affecting its validity and we know a default

15671579-- value to assign in that case. If the key and value are mandatory,

1568−-- use '(.:)' instead.

1580+-- use '.:' instead.

15691581--

15701582-- Example usage:

15711583--