I have made a ticket #11549 (https://ghc.haskell.org/trac/ghc/ticket/11549) requesting a -fshow-runtime-rep flag (recalling that the name levity will soon be outdated) as described in this thread. I will make sure this gets in for the release of 8.0.
Other points: - You're quite right that (.) could be generalized. But I'll wait for someone to really want this. - I don't have a non-contrived example of the use of ($) with unlifted types. It's quite possible that when adding the dirty runST hack, it was observed that an unlifted type would be OK. At that point, the type of ($) didn't need to become so elaborate. And now we're just trying not to change old (but perhaps unrequested) behavior. - For the record, this debate is entirely unrelated to the runST impredicativity hack. (Except, as noted above, perhaps in history.) That hack remains, basically unchanged. - On Feb 6, 2016, at 9:55 AM, Roman Cheplyaka <r...@ro-che.info> wrote: > > I would call this a simplification rather than a lie. This is a very convincing argument. - Thanks, also, for the voice of support. What I love about the Haskell community is that we can have an impassioned debate full of strong opinions, and it all very rarely devolves into a proper flame war. All the posts I've seen in this thread have been constructive and helpful. Thanks. Richard _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
