Hello, I have no strong feelings for or against allowing explicit foralls in types but I have a few questions/suggestions on the proposal in its current form (21 Nov 2010):
* Why is "forall" promoted to a keyword, rather then just being special in types as is in all implementations? I like the current status quo where "forall" can still be used in value expressions. * It seems that allowing "superflous" values in "foralls" could be useful for some future extensions. For example, if we had scoped type variables and explicit type application, then it may make sense to have quantified variables that do not appear in the rest of the type (but do appear in the definition of the function). I guess, we could revise things again if that was to ever happen but still, it seems to me that this might be more appropriate as an "unused variable" warning, rather then an error? * Is there any case where an empty "forall" is useful, and if not, why allow it? I guess it is a way to make it explicit that a value is monomorphic but i think that types like "forall. Int" look odd. -Iavor On Fri, Nov 19, 2010 at 5:08 PM, Ian Lynagh <[email protected]> wrote: > > Hi all, > > I've completed the ExplicitForAll proposal, started by Niklas Broberg > (but any errors are doubtless mine!): > > http://hackage.haskell.org/trac/haskell-prime/wiki/ExplicitForall > http://hackage.haskell.org/trac/haskell-prime/ticket/133 > > I imagine this is too late for H2011 (if that will actually be > happening?), but there wasn't an H2012 milestone, so I put it in H2011 > anyway. Please feel free to remilestone. > > > Thanks > Ian > > _______________________________________________ > Haskell-prime mailing list > [email protected] > http://www.haskell.org/mailman/listinfo/haskell-prime > _______________________________________________ Haskell-prime mailing list [email protected] http://www.haskell.org/mailman/listinfo/haskell-prime
