Re: [GHC] #8865: Cannot derive well-kinded instance of form ‘Category

[GHC]

#8865: Cannot derive well-kinded instance of form ‘Category
----------------------------------------------+----------------------------
        Reporter:  adinapoli                  |            Owner:
            Type:  bug                        |           Status:  closed
        Priority:  normal                     |        Milestone:  7.8.1
       Component:  Compiler                   |          Version:
      Resolution:  fixed                      |  7.8.1-rc2
Operating System:  MacOS X                    |         Keywords:
 Type of failure:  GHC rejects valid program  |     Architecture:  x86_64
       Test Case:                             |  (amd64)
        Blocking:                             |       Difficulty:  Unknown
                                              |       Blocked By:
                                              |  Related Tickets:
----------------------------------------------+----------------------------

Comment (by carter):

 the Pattern Arrows package used for purescript hits this exact same issue
 too. https://github.com/paf31/pattern-arrows

 {{{
 [1 of 1] Compiling Control.PatternArrows ( src/Control/PatternArrows.hs,
 dist/build/Control/PatternArrows.o )

 src/Control/PatternArrows.hs:32:92:
     Cannot derive well-kinded instance of form ‘C.Category (Pattern ...)’
       Class ‘C.Category’ expects an argument of kind ‘k -> k -> *’
     In the newtype declaration for ‘Pattern’
 }}}

 can i assume that the fix will be merged into 7.8 branch too? :)

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8865#comment:9>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler