[GHC] #10067: The Read Integer instance is too slow

[GHC]

#10067: The Read Integer instance is too slow
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        Reporter:  redneb            |                   Owner:
            Type:  feature request   |                  Status:  patch
        Priority:  low               |               Milestone:
       Component:  Core Libraries    |                 Version:  7.11
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  Runtime           |  Unknown/Multiple
  performance bug                    |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:                    |  Differential Revisions:  Phab:D645
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Comment (by ekmett):

 I have no principled objection to dramatically reducing the asymptotic
 cost of parsing integers assuming of course in good faith that the patch
 works.

 That said, it seems like it'd be a good idea to apply the same reasoning
 to the new `Natural` type that Herbert added in 7.10 as well.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10067#comment:4>
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