[GHC] #11303: Pattern matching against sets of strings sharing a prefix blows up pattern checker

[GHC]

#11303: Pattern matching against sets of strings sharing a prefix blows up pattern
checker
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        Reporter:  bgamari           |                Owner:  gkaracha
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.0.1
       Component:  Compiler          |              Version:  7.11
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  performance bug                    |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:  #11302            |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by RyanGlScott):

 Another place "in the wild" where this appears to occur is `text-icu`.
 Attempting to compile `Data.Text.ICU.Regex.Internal` very quickly eats up
 all of my RAM. I tried waiting for about half an hour for it to finish
 before giving up (then again, I was using a laptop with "only" 4 GB of
 RAM). If pattern matching is the culprit, then [https://github.com/bos
 /text-
 icu/blob/bfe19b0b4214a586ebcaecc33d460e679a5133f6/Data/Text/ICU/Regex/Internal.hsc#L177
 toURegexOpts] is the probable scene of the crime.

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11303#comment:2>
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