{-# LANGUAGE DeriveGeneric #-}
import Data.Serialize (Serialize)
import Data.Text (Text)
import GHC.Generics

data Foo = Foo Text deriving (Read,Show,Eq,Ord,Generic)
instance Serialize Foo
-- instance Serialize Text

如上所述,这会产生错误：

No instance for (Serialize Text)
  arising from a use of `Data.Serialize.$gdmput'
Possible fix: add an instance declaration for (Serialize Text)
In the expression: (Data.Serialize.$gdmput)
In an equation for `put': put = (Data.Serialize.$gdmput)
In the instance declaration for `Serialize Foo'

如果我取消注释实例序列化文本行,那么这个更加神秘的错误会出现：

No instance for (Data.Serialize.GSerialize (Rep Text))
  arising from a use of `Data.Serialize.$gdmput'
Possible fix:
  add an instance declaration for
  (Data.Serialize.GSerialize (Rep Text))
In the expression: (Data.Serialize.$gdmput)
In an equation for `put': put = (Data.Serialize.$gdmput)
In the instance declaration for `Serialize Text'

我可以手动实现Serialize实例,但这似乎是孤立实例将成为一个真正问题的情况,此外,我认为我不太了解Data.Text来快速正确地序列化/反序列化它.

这个问题有标准解决方案吗？ (我也没有坚持使用Grain的Serialize实例,但我一直有一些与使用二进制包有关的版本问题; binary-0.5.1.1似乎不能很好地支持泛型,我想避免写样板.)