[GHC] #14824: automatically select instance

[GHC]

#14824: automatically select instance
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        Reporter:  zaoqi             |                Owner:  (none)
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler          |              Version:  8.2.2
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by AntC):

 Perhaps (I'm just guessing) when you say

 > x0 x1 x2 x3 are Types.

 You mean not those are Types, but those are type ''variables''?

 Are you getting error messages? What are they? What flag settings do you
 have? (Have you set `OverlappingInstances`?)

 When you say

 > I can't write `a -> b`.

 ''Where'' can't you write that? Please give the full code; and the error
 messages.

 So far I can't see any "new feature" you're requesting.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14824#comment:5>
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