Re: [Haskell-cafe] Does GADTs imply ExistentialQuantification?

I get: Doaitse-2:~ doaitse$ ghci GHCi, version 8.4.3: http://www.haskell.org/ghc/ http://www.haskell.org/ghc/ :? for help Prelude> :set -XGADTs Prelude> data Q = forall a.Q a <interactive>:2:10: error: Not a data constructor: ‘forall’ Perhaps you intended to use ExistentialQuantification Prelude> It is weird that the forall (which actually is an exists) was enabled by the -XExplicitForAll Doaitse

Op 27 aug. 2018, om 3:42 heeft Cosmia Fu mailto:cosmiafu@gmail.com> het volgende geschreven:

Hey everyone,

I found that it seems that GADTs implies ExistentialQuantification, but not mentioned in the manual. Is it a bug? https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/glasgow_exts... https://downloads.haskell.org/~ghc/latest/docs/html/users_guide/glasgow_exts...

GHCi, version 8.4.3: http://www.haskell.org/ghc/ http://www.haskell.org/ghc/ :? for help Prelude> :set -XGADTs -XExplicitForAll Prelude> data Q = forall a. Q a Prelude>

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Cosmia Fu _______________________________________________ Haskell-Cafe mailing list To (un)subscribe, modify options or view archives go to: http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe Only members subscribed via the mailman list are allowed to post.