[GHC] #13114: UniqSet definition seems shady

[GHC]

#13114: UniqSet definition seems shady
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        Reporter:  dfeuer            |                Owner:  dfeuer
            Type:  task              |               Status:  closed
        Priority:  low               |            Milestone:  8.2.1
       Component:  Compiler          |              Version:  8.1
      Resolution:  fixed             |             Keywords:
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):  Phab:D3146
       Wiki Page:                    |
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Changes (by dfeuer):

 * status:  patch => closed
 * resolution:   => fixed
 * milestone:  8.4.1 => 8.2.1


Comment:

 Fixed in cbe569a56e2a82bb93a008beb56869d9a6a1d047

 {{{
 Upgrade UniqSet to a newtype

 The fundamental problem with type UniqSet = UniqFM is that UniqSet
 has a key invariant UniqFM does not. For example, fmap over
 UniqSet will generally produce nonsense.

 Upgrade UniqSet from a type synonym to a newtype.
 Remove unused and shady extendVarSet_C and addOneToUniqSet_C.
 Use cached unique in tyConsOfType by replacing unitNameEnv (tyConName tc)
 tc with unitUniqSet tc.
 Reviewers: austin, hvr, goldfire, simonmar, niteria, bgamari

 Reviewed By: niteria

 Subscribers: thomie

 Differential Revision: https://phabricator.haskell.org/D3146
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/13114#comment:2>
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