#14859: Allow explicit impredicativity -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.2.2 Resolution: | Keywords: | ImpredicativeTypes 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 goldfire): Impredicativity is perfectly fine in Core. (At least in theory. I'm sure panics await.) So giving users controlled access to it in source Haskell is safe, in that we won't launch the rockets. As we open this gate, horrors might await us on the other side, but they should all be type inference horrors, not type safety ones. I am thus in support of this direction of travel. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/14859#comment:6 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler