如何使用Aeson解码带有Unicode字符的JSON文件

(如果我应该说UTF8而不是Unicode，很抱歉.)

我已经遇到了this question个人，但几分钟后就想不通了.

这个问题的出发点和我的问题如下

import Data.Aeson
import qualified Data.Text.Encoding as E (encodeUtf8)
import qualified Data.ByteString.Lazy.Char8 as C8 (pack)
import qualified Data.Text as T (pack)

main :: IO ()
main = do
  print (foo "{ \"foo\": \"bar\"}" :: Maybe Value)
  print (foo "{ \"foo\": \"bòz\"}" :: Maybe Value)
  where
    foo = decode . C8.pack

将打印

Just (Object (fromList [("foo",String "bar")]))
Nothing

答案和 comments 都提到了利用Data.Text.Encoding中的encodeUtf8的解决方案.但如何做到呢？

• C8.pack等于String -> ByteString，
• E.encodeUtf8等于Text -> ByteString，
• "{ \"foo\": \"bòz\"}"等于String，

所以我想，如果我想用E.encodeUtf8，我需要go 掉C8.pack，作为类型为String -> Text的函数，而T.pack似乎就是这样一个函数.然而，以下几点:

import Data.Aeson
import qualified Data.Text.Encoding as E (encodeUtf8)
import qualified Data.ByteString.Lazy.Char8 as C8 (pack)
import qualified Data.Text as T (pack)

main :: IO ()
main = do
  print (foo "{ \"foo\": \"bar\"}" :: Maybe Value)
  print (foo "{ \"foo\": \"bòz\"}" :: Maybe Value)
  where
    foo = decode . E.encodeUtf8 . T.pack

编译失败，出现错误

    • Couldn't match type ‘bytestring-0.11.5.3:Data.ByteString.Internal.Type.ByteString’
                     with ‘Data.ByteString.Lazy.Internal.ByteString’
      Expected: Data.Text.Internal.Text
                -> Data.ByteString.Lazy.Internal.ByteString
        Actual: Data.Text.Internal.Text
                -> bytestring-0.11.5.3:Data.ByteString.Internal.Type.ByteString
      NB: ‘Data.ByteString.Lazy.Internal.ByteString’
            is defined in ‘Data.ByteString.Lazy.Internal’
          ‘bytestring-0.11.5.3:Data.ByteString.Internal.Type.ByteString’
            is defined in ‘Data.ByteString.Internal.Type’
    • In the first argument of ‘(.)’, namely ‘E.encodeUtf8’
      In the second argument of ‘(.)’, namely ‘E.encodeUtf8 . T.pack’
      In the expression: decode . E.encodeUtf8 . T.pack
   |
11 |     foo = decode . E.encodeUtf8 . T.pack
   |                    ^^^^^^^^^^^^