[GHC] #3676: realToFrac doesn't sanely convert between floating types

[GHC]

#3676: realToFrac doesn't sanely convert between floating types
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    Reporter:  draconx            |        Owner:  simonmar    
        Type:  bug                |       Status:  assigned    
    Priority:  normal             |    Milestone:  6.12.2      
   Component:  libraries (other)  |      Version:  6.12.1      
    Keywords:                     |   Difficulty:              
          Os:  Unknown/Multiple   |     Testcase:              
Architecture:  x86_64 (amd64)     |      Failure:  None/Unknown
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Comment(by simonmar):

 I think it's pretty straightforward.  `toRational` should be able to
 convert NaN, Infinity and -Infinity correctly to Rational, and there is
 already code in fromRational to convert them back to the floating point
 types correctly (I imagine it's there in order to make things like `read
 "NaN"` work).

 The Haskell report doesn't say anything about the implementation of
 `toRational`, so I think this is correct.  I'm validating a patch now.

-- 
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/3676#comment:8>
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