[GHC] #8671: Rebindable syntax creates bogus warning

[GHC]

#8671: Rebindable syntax creates bogus warning
-------------------------------------------------+-------------------------
        Reporter:  thomaseding                   |            Owner:
            Type:  bug                           |           Status:  new
        Priority:  normal                        |        Milestone:
       Component:  Compiler                      |          Version:  7.6.3
      Resolution:                                |         Keywords:
Operating System:  Windows                       |     Architecture:
 Type of failure:  Incorrect warning at          |  Unknown/Multiple
  compile-time                                   |       Difficulty:
       Test Case:                                |  Unknown
        Blocking:                                |       Blocked By:
                                                 |  Related Tickets:
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Comment (by thomaseding):

 Just some initial thoughts that may or may not be useful -- concerning
 conditionally suppressing the warning based on what the syntax is rebound
 to...

 ----

 Consider
 {{{
 blah = do
     x -- suppose that GHC issues the warning for this (whether the warning
 is correct or not)
     y
 }}}

 Translates to
 {{{
 blah = x >> y
 }}}

 Before issuing the warning, consider translating the code to
 {{{
 blah = x >>= (\_ -> y)
 }}}

 If this compiles, then issue the warning. Otherwise do not.

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/8671#comment:3>
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