[GHC] #11548: Absolutely misleading error message on kind error
GHC
ghc-devs at haskell.org
Sun Sep 11 23:19:30 UTC 2016
#11548: Absolutely misleading error message on kind error
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Reporter: mniip | Owner: goldfire
Type: bug | Status: new
Priority: high | Milestone:
Component: Compiler (Type | Version: 8.1
checker) |
Resolution: | Keywords: TypeInType
Operating System: Unknown/Multiple | Architecture:
Type of failure: Incorrect | Unknown/Multiple
warning at compile-time | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s):
Wiki Page: |
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Comment (by RyanGlScott):
For reference, here is the current error message in GHC 8.0.1/HEAD:
{{{
• Couldn't match type ‘* -> *’ with ‘*’
Expected type: Proxy Maybe
Actual type: Proxy Maybe
Use -fprint-explicit-kinds to see the kind arguments
• In the first argument of ‘fun’, namely ‘(Proxy :: Proxy Maybe)’
In the expression: fun (Proxy :: Proxy Maybe)
In an equation for ‘bug’: bug = fun (Proxy :: Proxy Maybe)
}}}
I think this is much clearer, and doesn't incorrectly label the type as a
kind.
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11548#comment:7>
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