[GHC] #16261: [] interpreted as an overloaded list in rule LHS

[GHC]

#16261: [] interpreted as an overloaded list in rule LHS
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        Reporter:  dfeuer            |                Owner:  (none)
            Type:  bug               |               Status:  new
        Priority:  normal            |            Milestone:  8.10.1
       Component:  Compiler          |              Version:  8.6.3
      Resolution:                    |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Incorrect         |  Unknown/Multiple
  error/warning at compile-time      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
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Comment (by simonpj):

 > Do you agree with my opinion that OverloadedLists should never be
 enabled in a rule LHS, regardless of which extensions are enabled in the
 module?

 No: I think the same extensions should be in scope everywhere otherwise
 people will say "but I wrote `f []` and it didn't match a rule whose LHS
 was `f []`".

 However I do agree that it's bizarre that `OverloadedLists` seems to be
 enabled on the rule LHS but not in the rest of the module.  Deeply
 strange.  We just need to understand more about what is happening.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/16261#comment:12>
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