aeson

来源： https://stackoverflow.com/questions/52553510/how-to-concatmap-over-all-key-value-pairs-in-an-aeson-object-using-lenses

问题 I've been starting at https://www.stackage.org/haddock/lts-12.1/lens-aeson-1.0.2/Data-Aeson-Lens.html and https://www.stackage.org/haddock/lts-12.1/lens-4.16.1/Control-Lens-Fold.html trying to figure out how to write an expression that allows me to construct something of the following type: import Data.Aeson as A functionIWant :: (Vector A.Value) -> (A.Value -> [a]) -> [a] 回答1: There are two lens functions that are used to "lift" regular Foldable -related functions to the lensy world: folded

问题 I've been starting at https://www.stackage.org/haddock/lts-12.1/lens-aeson-1.0.2/Data-Aeson-Lens.html and https://www.stackage.org/haddock/lts-12.1/lens-4.16.1/Control-Lens-Fold.html trying to figure out how to write an expression that allows me to construct something of the following type: import Data.Aeson as A functionIWant :: (Vector A.Value) -> (A.Value -> [a]) -> [a] 回答1: There are two lens functions that are used to "lift" regular Foldable -related functions to the lensy world: folded

问题 I've been starting at https://www.stackage.org/haddock/lts-12.1/lens-aeson-1.0.2/Data-Aeson-Lens.html and https://www.stackage.org/haddock/lts-12.1/lens-4.16.1/Control-Lens-Fold.html trying to figure out how to write an expression that allows me to construct something of the following type: import Data.Aeson as A functionIWant :: (Vector A.Value) -> (A.Value -> [a]) -> [a] 回答1: There are two lens functions that are used to "lift" regular Foldable -related functions to the lensy world: folded

问题 I have data in form of pairs of two strings, where first is the key identifying shape of the JSON delivered as the second one. fooooo {"a": 123} barrrr {"a": 123, "b": 123} fooooo {"a": 123} I would like to parse it to same data type, based on the fopooo , baasdasda1 , etc : data Test = Foo { a :: Int , b :: Int } | Bar { a :: Int } deriving (Show, Generic) In the Aeson there is a tag feature, but it seems to require presence of the tag inside the object. Is there some way to handle it like

问题 I have data in form of pairs of two strings, where first is the key identifying shape of the JSON delivered as the second one. fooooo {"a": 123} barrrr {"a": 123, "b": 123} fooooo {"a": 123} I would like to parse it to same data type, based on the fopooo , baasdasda1 , etc : data Test = Foo { a :: Int , b :: Int } | Bar { a :: Int } deriving (Show, Generic) In the Aeson there is a tag feature, but it seems to require presence of the tag inside the object. Is there some way to handle it like

问题 How I can parse the input json inside this file ? https://github.com/smogon/pokemon-showdown/blob/master/data/moves.js For the secondary and flags properties? They are optional and contains variant type. A minimal example would be this one: [ {}, { "secondary": false }, { "secondary": { "chance": 10, "boosts": { "spd": -1 } } }, { "secondary": { "chance": 30, "volatileStatus": "flinch" } }, { "secondary": { "chance": 30 } }, { "secondary": { "chance": 10, "self": { "boosts": { "atk": 1, "def"

问题 I'm using aeson-schemas-1.0.3 and I want to construct values of Object Example without round-tripping through an external serialized representation. It seems like a hack and I'm worried about the performance impact. I have this schema defined: type Example = [schema| { example: Text, } |] I want to be able to write something like this: coerceJson $ object [ "example" .= ("Example" :: Text) ] I have a workaround which does allow that, but it involves encoding to a ByteString and decoding to

问题 I can't get aeson to parse an UTCTime value. I tried to encode one and feed it back, but that didn't work: Prelude Data.Aeson Data.Time.Clock> getCurrentTime >>= (print . encode) "\"2013-10-17T09:42:49.007Z\"" Prelude Data.Aeson Data.Time.Clock> decode "2013-10-17T09:42:49.007Z" :: Maybe UTCTime Nothing Prelude Data.Aeson Data.Time.Clock> decode "\"2013-10-17T09:42:49.007Z\"" :: Maybe UTCTime Nothing The FromJSON instance of the UTCTime type is the following (ref): instance FromJSON UTCTime

问题 I can't get aeson to parse an UTCTime value. I tried to encode one and feed it back, but that didn't work: Prelude Data.Aeson Data.Time.Clock> getCurrentTime >>= (print . encode) "\"2013-10-17T09:42:49.007Z\"" Prelude Data.Aeson Data.Time.Clock> decode "2013-10-17T09:42:49.007Z" :: Maybe UTCTime Nothing Prelude Data.Aeson Data.Time.Clock> decode "\"2013-10-17T09:42:49.007Z\"" :: Maybe UTCTime Nothing The FromJSON instance of the UTCTime type is the following (ref): instance FromJSON UTCTime