[GHC] #5688: instance Read Integer/Rational/Double readsPrec out of memory and crash due to exponential notation

[GHC]

#5688: instance Read Integer/Rational/Double readsPrec out of memory and crash due
to exponential notation
-------------------------------------+------------------------------------
        Reporter:  gracjan           |            Owner:  igloo
            Type:  bug               |           Status:  closed
        Priority:  highest           |        Milestone:  7.4.2
       Component:  libraries/base    |          Version:  6.12.3
      Resolution:  fixed             |         Keywords:
Operating System:  Unknown/Multiple  |     Architecture:  Unknown/Multiple
 Type of failure:  Runtime crash     |       Difficulty:  Unknown
       Test Case:  T7034             |       Blocked By:
        Blocking:                    |  Related Tickets:
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Comment (by hvr):

 I've been looking at [afcddc5ce033de84/base] which added the
 `Text.Read.Lex.Number` data type, and two functions to convert `Number`
 into `Integer` or `Rational`.

 However, the type `Number` wasn't exported (which caused a Haddock warning
 and caught my attention). Is there a reason not to export `Number`
 (without any constructor)?

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5688#comment:66>
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