[GHC] #12446: Doesn't suggest TypeApplications when `~` used prefix

[GHC]

#12446: Doesn't suggest TypeApplications when `~` used prefix
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           Reporter:  Iceland_jack   |             Owner:
               Type:  bug            |            Status:  new
           Priority:  normal         |         Milestone:
          Component:  Compiler       |           Version:  8.0.1
           Keywords:                 |  Operating System:  Unknown/Multiple
       Architecture:                 |   Type of failure:  None/Unknown
  Unknown/Multiple                   |
          Test Case:                 |        Blocked By:
           Blocking:                 |   Related Tickets:
Differential Rev(s):                 |         Wiki Page:
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 {{{
 $ ghci -ignore-dot-ghci
 GHCi, version 8.0.1: http://www.haskell.org/ghc/  :? for help
 Prelude> :t undefined @(_ ~ _)

 <interactive>:1:1: error:
     Pattern syntax in expression context: undefined@(_ (~(_)))
     Did you mean to enable TypeApplications?
 }}}

 It is suggested with non-`~` type operators

 {{{
 Prelude> :t undefined @((+) _ _)

 <interactive>:1:1: error:
     Pattern syntax in expression context: undefined@((+) (_) (_))
     Did you mean to enable TypeApplications?
 }}}

 but not with

 {{{
 Prelude> :t undefined @((~) _ _)

 <interactive>:1:15: error: parse error on input ‘)’
 }}}

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Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/12446>
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