[GHC] #15242: Typechecker sometimes doesn't preserve HsPar in original source.

[GHC]

#15242: Typechecker sometimes doesn't preserve HsPar in original source.
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        Reporter:  wz1000            |                Owner:  (none)
            Type:  bug               |               Status:  patch
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.5
  checker)                           |
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  Other             |            Test Case:  T15242
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D4822
       Wiki Page:                    |
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Comment (by Simon Peyton Jones <simonpj@…>):

 In [changeset:"aab3c6d18416b3bc8e1378dfc4d485a9307ca5c7/ghc" aab3c6d/ghc]:
 {{{
 #!CommitTicketReference repository="ghc"
 revision="aab3c6d18416b3bc8e1378dfc4d485a9307ca5c7"
 Refactor TcExpr.tcSeq

 The function TcExpr.tcSeq seemed much longer that is really
 justifiable; and was set to get worse with the fix to Trac #15242.

 This patch refactors the special cases for function applications,
 so that the special case for 'seq' can use the regular tcFunApp,
 which makes the code both clearer and shorter.  And smooths the
 way for #15242.

 The special case for 'tagToEnum#' is even more weird and ad-hoc,
 so I refrained from meddling iwth it for now.

 I also combined HsUtils.mkHsAppType and mkHsAppTypeOut, so that
 I could have a single 'wrapHsArgs' function, thereby fixing a
 ToDo from Alan Zimmerman.  That means tha tmkHsAppType now has
 an equality predicate, but I guess that's fair enough.
 }}}

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15242#comment:3>
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