[GHC] #7937: Misleading "Precedence parsing error" when using an undefined operator

[GHC]

#7937: Misleading "Precedence parsing error" when using an undefined operator
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Reporter:  ktvoelker         |          Owner:                  
    Type:  bug               |         Status:  new             
Priority:  normal            |      Component:  Compiler        
 Version:  7.6.3             |       Keywords:                  
      Os:  Unknown/Multiple  |   Architecture:  Unknown/Multiple
 Failure:  None/Unknown      |      Blockedby:                  
Blocking:                    |        Related:  #2993           
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 I was using QuickCheck and wrote something like this:

 a > 0 ==> a == b

 But I hadn't imported (==>), and I got an error about mixing two operators
 with the same fixity (the two comparisons). This error was misleading,
 since once I imported ==>, which has a lower fixity, there was no problem.

 I have a complete example file to attach.

 This might be identical to #2993, but the situation there was not quite
 the same, so I am filing a new bug rather than reopening it.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/7937>
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