Re: partially applied type synonyms

Arie Peterson writes:

Is there a good reason that partially applied type synonyms cannot be made instances of classes?

[...]

Partially applied type synonyms are, in a sense, the anonymous functions at the type level, and one might argue that they deserve the same 'first-class member status' as the lambda at the value level.

According to SPJ, the problem seems to be requiring higher-order unification for this to happen: http://www.haskell.org/pipermail/glasgow-haskell-users/2005-April/008340.htm... Does anyone here know (as SPJ's response is quite a few years old) if there's been made any progress since back then? cheers, hvr