[GHC] #12418: Make `MonadCont (ContT r m)` polykinded (r::k), (m::k -> Type)
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Fri Jul 22 19:22:33 UTC 2016
#12418: Make `MonadCont (ContT r m)` polykinded (r::k), (m::k -> Type)
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Reporter: Iceland_jack | Owner:
Type: feature request | Status: new
Priority: normal | Milestone:
Component: Core Libraries | Version: 8.0.1
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture:
| Unknown/Multiple
Type of failure: None/Unknown | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
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Comment (by Iceland_jack):
Without the kind the error was also confusing
{{{
• No instance for (MonadCont (ContT r1 m1))
arising from a use of ‘callCC’
• In the expression:
callCC :: ((a -> ContT r m b) -> ContT r m a) -> ContT r m a
}}}
It took me a while to recognize it was a ''kind'' problem, the instance
certainly seems to be there!
{{{#!hs
instance MonadCont (ContT r m)
}}}
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12418#comment:2>
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