[GHC] #7609: Backticks in an an error message

19 Jan 2013

      #7609: Backticks in an an error message
----------------------------------------------+-----------------------------
Reporter:  monoidal                           |          Owner:                  
    Type:  bug                                |         Status:  new             
Priority:  normal                             |      Component:  Compiler        
 Version:  7.6.1                              |       Keywords:                  
      Os:  Unknown/Multiple                   |   Architecture:  Unknown/Multiple
 Failure:  Incorrect warning at compile-time  |      Blockedby:                  
Blocking:                                     |        Related:                  
----------------------------------------------+-----------------------------
 {{{
 {-# LANGUAGE TypeOperators #-}
 data X a b

 f :: (a `X` a, Maybe)
 f = undefined
 }}}

 gives an error message:

 {{{
 X.hs:4:16:
     Expecting one more argument to `Maybe'
     In the type signature for `f': f :: (a X a, Maybe)
                                          ^^^^^
 }}}

 which should be {{{a `X` a}}}. The same thing happens in constraints, such
 as

 {{{
 f :: (a `X` a) => Maybe
 }}}

-- 
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/7609
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