[GHC] #13909: Misleading error message when partially applying a data type with a visible quantifier in its kind

GHC ghc-devs at haskell.org
Thu Sep 14 19:35:56 UTC 2017


#13909: Misleading error message when partially applying a data type with a visible
quantifier in its kind
-------------------------------------+-------------------------------------
        Reporter:  RyanGlScott       |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.0.1
  checker)                           |
      Resolution:                    |             Keywords:  TypeInType
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Ben Gamari <ben@…>):

 In [changeset:"89c8d4d26416381a088eab6f5b8744927e349e69/ghc"
 89c8d4d2/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="89c8d4d26416381a088eab6f5b8744927e349e69"
 Fix #13909 by tweaking an error message.

 GHC was complaining about numbers of arguments when the real
 problem is impredicativity.

 test case: typecheck/should_fail/T13909
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13909#comment:3>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler


More information about the ghc-tickets mailing list