[GHC] #14135: PatternSynonyms regression in GHC HEAD (expectJust mkOneConFull)

[GHC]

#14135: PatternSynonyms regression in GHC HEAD (expectJust mkOneConFull)
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        Reporter:  RyanGlScott       |                Owner:  carlostome
            Type:  bug               |               Status:  new
        Priority:  highest           |            Milestone:  8.4.1
       Component:  Compiler          |              Version:  8.3
      Resolution:                    |             Keywords:
                                     |  PatternSynonyms
Operating System:  Unknown/Multiple  |         Architecture:
 Type of failure:  Compile-time      |  Unknown/Multiple
  crash or panic                     |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3981
       Wiki Page:                    |
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Comment (by RyanGlScott):

 That sounds like a great suggestion to me!

 This might even scratch an itch I discovered in
 https://ghc.haskell.org/trac/ghc/ticket/14059#comment:2. There, I lamented
 that fact that I wanted to write a `COMPLETE` set for a group of conlikes
 whose types are headed by `Sing`. The problem was that each conlike wasn't
 of type, say, `Sing (a :: k)`, but rather the more specific type `Sing (a
 :: Bool)`. But with the proposal laid out in comment:8, I don't believe
 this would be an issue, since we could simply filter out anything in a
 `COMPLETE` set that wasn't of type `Sing (a :: Bool)`. Nice.

-- 
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/14135#comment:9>
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