[GHC] #15471: Polymorphism, typed splices and type inference don't mix

[GHC]

#15471: Polymorphism, typed splices and type inference don't mix
-------------------------------------+-------------------------------------
        Reporter:  mpickering        |                Owner:  (none)
            Type:  bug               |               Status:  closed
        Priority:  normal            |            Milestone:  8.8.1
       Component:  Template Haskell  |              Version:  8.4.3
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  GHC rejects       |  Unknown/Multiple
  valid program                      |            Test Case:  th/T15471
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D5286,
       Wiki Page:                    |  https://gitlab.haskell.org/ghc/ghc/merge_requests/106
-------------------------------------+-------------------------------------
Changes (by RyanGlScott):

 * testcase:   => th/T15471
 * status:  new => closed
 * differential:  Phab:D5286 => Phab:D5286,
     https://gitlab.haskell.org/ghc/ghc/merge_requests/106
 * resolution:   => fixed
 * milestone:  8.10.1 => 8.8.1


Comment:

 Landed in
 [https://gitlab.haskell.org/ghc/ghc/commit/c2455e647501c5a382861196b64df3dd05b620a2
 c2455e647501c5a382861196b64df3dd05b620a2]:

 {{{
 commit c2455e647501c5a382861196b64df3dd05b620a2
 Author: Matthew Pickering <matthewtpickering at gmail.com>
 Date:   Wed Jan 9 14:52:30 2019 +0000

     Run typed splices in the zonker

     Summary:
     This fixes #15471

     In the typechecker we check that the splice has the right type but we
     crucially don't zonk the generated expression. This is because we
 might
     end up unifying type variables from outer scopes later on.

     Reviewers: simonpj, goldfire, bgamari

     Subscribers: rwbarton, carter

     GHC Trac Issues: #15471

     Differential Revision: https://phabricator.haskell.org/D5286
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15471#comment:18>
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