所以我有这个代码抛出一个我无法找到任何信息的错误。这是代码:
{-# LANGUAGE DataKinds #-}
module Main where
import Network.Google
class ( HasScope '["https://www.googleapis.com/auth/datastore"] a
, GoogleRequest a)
=> IsRequest a
这是错误:
• Illegal constraint ‘HasScope
'["https://www.googleapis.com/auth/datastore"]
a’ in a superclass context
(Use UndecidableInstances to permit this)
• In the context: (HasScope
'["https://www.googleapis.com/auth/datastore"] a,
GoogleRequest a)
While checking the super-classes of class ‘IsRequest’
In the class declaration for ‘IsRequest’
这里发生了什么?我正在使用GHC 8.0.1。