[GHC] #11385: Unify named wildcards in different type applications

GHC ghc-devs at haskell.org
Tue Jul 5 16:54:23 UTC 2016


#11385: Unify named wildcards in different type applications
-------------------------------------+-------------------------------------
        Reporter:  Iceland_jack      |                Owner:
            Type:  feature request   |               Status:  new
        Priority:  normal            |            Milestone:
       Component:  Compiler (Type    |              Version:  8.1
  checker)                           |             Keywords:
      Resolution:                    |  NamedWildCards TypeApplications
Operating System:  Unknown/Multiple  |         Architecture:
                                     |  Unknown/Multiple
 Type of failure:  None/Unknown      |            Test Case:
      Blocked By:                    |             Blocking:
 Related Tickets:                    |  Differential Rev(s):
       Wiki Page:                    |
-------------------------------------+-------------------------------------

Comment (by Iceland_jack):

 Continuing with ticket comment:4:ticket:11350, these make sense to me

 {{{#!hs
 asTypeOf @a = const @a @a

 endomap @a = fmap @[] @a @a
 }}}

 but wait, `asTypeOf @a` × `endomap @a` bind a new type variable. How does
 that mesh with your intuition from comment:9:ticket:11350?

 {{{#!hs
 asTypeOf = \ @a -> const @a @a

 -- vs

 asTypeOf @a = const @a @a
 }}}

--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/11385#comment:4>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler


More information about the ghc-tickets mailing list