Brandon Allbery wrote:

On Mon, Feb 23, 2015 at 12:59 PM, Andrew Farmer wrote:

...

I'm guessing the problem is that its not Haskell 98/2010? I think GHC has a policy to do only what the spec says by default. Is that still true now that AMP is implemented?

I think the main worry is that it steals syntax, specifically the `forall` keyword, which is just an identifier in H'98 and H'2010. (And some bikeshedding over `forall` being inappropriate for this use, but I suspect that ship sailed long ago.)

The real problem with this syntax is the irregular and completely unnecessary overloading of the dot. As if the dot weren't overloaded enough! A much better choice would have been forall a b c in ... This could still be changed: we could have both variants in parallel for a while, then slowly deprecate the dot and finally scrap it. Cheers Ben -- "There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult." ― C.A.R. Hoare