Re: New type of ($) operator in GHC 8.0 is problematic

On 02/05/2016 01:31 AM, Edward Z. Yang wrote:

I'm not really sure how you would change the type of 'id' based on a language pragma.

How do people feel about a cosmetic fix, where we introduce a new pragma, {-# LANGUAGE ShowLevity #-} which controls the display of levity arguments/TYPE. It's off by default but gets turned on by some extensions like MagicHash (i.e. we only show levity if you have enabled extensions where the distinction matters).

Yes, I am surprised this isn't the way it's been done. The levity arguments should totally be hidden unless requested explicitly. I'd only expect this to be a ghc flag (-fshow-levity), not a language pragma, since it should only affect the way types are /shown/. Roman