[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 Ben Gamari <ben@…>):

 In [changeset:"fcc76493c8b35001fc1b22738cc64ff9506e278a/ghc"
 fcc76493/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="fcc76493c8b35001fc1b22738cc64ff9506e278a"
 Introduce negative patterns for literals (addresses #11303)

 Introduce negative patterns for literals. In addition to storing term
 constraints for literals (checked at the end by the term oracle), also
 check eagerly, using negative patterns. This means generation of smaller
 sets (covered, uncovered, and divergent), instead of generating big sets
 and pruning afterwards.

 Test Plan: validate

 Reviewers: austin, bgamari

 Reviewed By: bgamari

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D1716

 GHC Trac Issues: #11303
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11303#comment:5>
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