解析JSON haskell
我正在尝试访问请求中的内部解析JSON haskell,json,haskell,functional-programming,request,wreq,Json,Haskell,Functional Programming,Request,Wreq,我正在尝试访问请求中的内部对象。这是我的代码: {-# LANGUAGE OverloadedStrings #-} import Network.Wreq import Control.Lens import Data.Aeson import Data.Map as Map type Resp = Response (Map String Value) main = do r <- asJSON =<< get "https://bittrex.com/
对象
。这是我的代码:
{-# LANGUAGE OverloadedStrings #-}
import Network.Wreq
import Control.Lens
import Data.Aeson
import Data.Map as Map
type Resp = Response (Map String Value)
main = do
r <- asJSON =<< get "https://bittrex.com/api/v1.1/public/getticker?market=BTC-LTC" :: IO Resp
let result = (r ^. responseBody)
print result
我试图访问“result”键的对象,然后访问其中的值。我不知道该怎么做,我把AESON和^?
操作符弄乱了,wreq
提供了这些操作符,但它们对我不起作用。{-#语言重载字符串}
{-# LANGUAGE OverloadedStrings #-}
import Control.Lens
import Network.Wreq
import Data.Aeson.Lens
import Data.HashMap.Lazy (HashMap)
import Data.Text (Text)
main = do
r <- asValue =<< get "https://bittrex.com/api/v1.1/public/getticker?market=BTC-LTC"
let result =
(r :: Response Value)
-- get the Value out of the Response
^? responseBody
-- The Value must be an Object, then unwrap the contained (HashMap Text Value)
. _Object
-- In the map {"message": ..., "result": ...}, get the "result".
. ix "result"
-- This must be an Object, unwrap the (HashMap Text Value)
. _Object
print (result :: HashMap Text Value)
-- How types line up:
--
-- responseBody . _Object . ix "result" . _Object
-- :: Traversal' (Response Value) (HashMap Text Value)
--
-- responseBody :: Lens' (Response Value) Value
-- _Object :: Traversal' Value (HashMap Text Value)
-- ix "result" :: Traversal' (HashMap Text Value) Value
-- _Object :: Traversal' Value (HashMap Text Value)
进口管制.镜头
导入网络.Wreq
导入Data.Aeson.Lens
导入Data.HashMap.Lazy(HashMap)
导入数据。文本(Text)
main=do
r{-#语言重载字符串}
进口管制.镜头
导入网络.Wreq
导入Data.Aeson.Lens
导入Data.HashMap.Lazy(HashMap)
导入数据。文本(Text)
main=do
R
{-# LANGUAGE OverloadedStrings #-}
import Control.Lens
import Network.Wreq
import Data.Aeson.Lens
import Data.HashMap.Lazy (HashMap)
import Data.Text (Text)
main = do
r <- asValue =<< get "https://bittrex.com/api/v1.1/public/getticker?market=BTC-LTC"
let result =
(r :: Response Value)
-- get the Value out of the Response
^? responseBody
-- The Value must be an Object, then unwrap the contained (HashMap Text Value)
. _Object
-- In the map {"message": ..., "result": ...}, get the "result".
. ix "result"
-- This must be an Object, unwrap the (HashMap Text Value)
. _Object
print (result :: HashMap Text Value)
-- How types line up:
--
-- responseBody . _Object . ix "result" . _Object
-- :: Traversal' (Response Value) (HashMap Text Value)
--
-- responseBody :: Lens' (Response Value) Value
-- _Object :: Traversal' Value (HashMap Text Value)
-- ix "result" :: Traversal' (HashMap Text Value) Value
-- _Object :: Traversal' Value (HashMap Text Value)