wren ng thornton
wren at community.haskell.org
Wed Jun 24 17:43:46 EDT 2009
Niklas Broberg wrote:
> Simon Peyton-Jones wrote:
>> On ExistentialQuantification, I personally think we should deprecate the entire construct, suggesting GADT-style syntax instead.
> +1, though I was afraid to suggest something that radical. I might
> write a separate proposal for that then, to keep the discussion here
> focused on ExplicitForall.
There's the minor quibble that ExistentialQuantification is weaker and
so using full GADT syntax allows writing types that can't fit into
ExistentialQuantification. But I think removing the current wart is much
better than introducing this minor one.
>> If you can form a consensus, go for it.
> Alright, let's set an actual discussion period of 2 weeks for
> ExplicitForall. If there is no opposition by then, we can add
> ExplicitForall to the registered extensions in cabal as a first step.
+1 to adding an ExplicitForall syntactic language pragma, as per your
proposal (which implicitly enables it when using a semantic/type pragma
that requires it).
More information about the Libraries