Hi chessai, It is indeed not possible in source Haskell at the moment.
Cheers, Csongor > On 7 Apr 2019, at 17:41, chessai . <[email protected]> wrote: > > Hi devs, > > Is it possible to programmatically recover the role of a type variable? > > Or, possibly, a list of the roles of the type variables from left to right? > > For example, if i have: > > data Foo a = Foo (1) > newtype Bar a b = Bar (a -> b) (1) > > Getting the role list of (1) would give me [Phantom], and (2) would give me > [Representational, Representational]. > > I know in compiler/types/TyCon.hs that TyCon has a list of Roles in it, but > there doesn't seem to be any machinery available to do this in source haskell. > > Thanks > > > > > > _______________________________________________ > ghc-devs mailing list > [email protected] > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs _______________________________________________ ghc-devs mailing list [email protected] http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
