
24 Nov
2009
24 Nov
'09
1:44 p.m.
On Tue, Nov 24, 2009 at 6:02 PM, Simon Peyton-Jones
It used to be, because GHC used to implement so-called "deep skolemisation". See Section 4.6.2 of http://research.microsoft.com/en-us/um/people/simonpj/papers/higher-rank/put...
Deep skolemisation was an unfortunate casualty of the push to add impredicative polymoprhism. However, as I mentioned in an earlier email, I'm currently planning to take impredicative polymorphism *out*, which means that deep skolemisation might come back *in*.
Ok nice because I'm very used to refactor code like: 'f x = g x' to 'f = g' for all f and g. Thanks, Bas