[Haskell] Rank-N types with (.) composition

[David Feuer]

On Tue, Feb 10, 2015 at 4:28 PM, Dan Doel <dan.doel at gmail.com> wrote:

> Also, I think ($) is the way it is specifically because 'runST $ ...' is
> considered useful and common enough to warrant an ad-hoc solution. There
> have been other ad-hoc solutions in the past, but redesigning inference to
> not be ad-hoc about it would be very difficult at best.
>
> -- Dan

Of the ad-hoc solutions available, I'd personally think the least
surprising would be to make  f $ x special syntax instead of an
operator. The main tricky bit would be preserving source for error
messages; the type checker would have to keep track, for each
application, of whether it was a standard juxtaposition or whether it
used $.