#1965: Allow unconstrained existential contexts in newtypes -------------------------------------+------------------------------------- Reporter: guest | Owner: Type: feature request | Status: new Priority: normal | Milestone: Component: Compiler | Version: 6.8.1 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Description changed by simonpj: @@ -9,0 +9,2 @@ + + The wiki page [wiki:NewtypeOptimizationForGADTS] summarises the proposal New description: Declarations like {{{ newtype Bar = forall a. Bar (Foo a) }}} ought to be allowed so long as no typeclass constraints are added. Right now, this requires data rather than newtype. The wiki page [wiki:NewtypeOptimizationForGADTS] summarises the proposal -- -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/1965#comment:30 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler