[GHC] #5692: Source code with large floating constants in exponential notation cannot be compiled

[GHC]

#5692: Source code with large floating constants in exponential notation cannot be
compiled
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        Reporter:  gracjan           |                   Owner:  pcapriotti
            Type:  bug               |                  Status:  new
        Priority:  normal            |               Milestone:  8.0.1
       Component:  Compiler          |                 Version:  7.2.1
      Resolution:                    |                Keywords:
Operating System:  Unknown/Multiple  |            Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash                              |               Test Case:
      Blocked By:                    |                Blocking:
 Related Tickets:  5688              |  Differential Revisions:
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Changes (by WrenThornton):

 * cc: wren@… (added)


Comment:

 FWIW, the [http://hackage.haskell.org/package/bytestring-lexing
 bytestring-lexing] library has extremely efficient implementations of
 reading real literals for types which have limited precision (e.g.,
 `Float` and `Double`). The functions in question are `readDecimalLimited`
 and `readExponentialLimited` in  `Data.ByteString.Lex.Fractional`. The
 repo for the package also includes benchmarks.

 Surely GHC doesn't need to optimize lexing quite so much as bytestring-
 lexing has done, but in the interest of minimizing code
 duplication/maintenance, I would be totally fine having bytestring-lexing
 become one of the core libraries GHC uses.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/5692#comment:7>
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