A modest counter-proposal to this idea: What if we just stopped requiring commas in import/export lists? As far as I can tell, they're not necessary for proper parsing.
This doesn't solve other problems, but I'm not convinced every problem in this domain needs the same solution. In particular, I'm -1 on allowing a loose interpretation of commas in lists, as it seems very strange to have commas in lists and commas in tuples have a different meaning. (I'm +1 on fixing import/export lists, though.) Richard On Sep 25, 2014, at 8:06 AM, Herbert Valerio Riedel <hvrie...@gmail.com> wrote: > On 2014-09-25 at 13:34:16 +0200, Daniel Trstenjak wrote: > > [...] > >> One compromise could be, that additional commatas in literal lists >> are only allowed at the beginning and at the end. > > ...another idea could be to make it a separate Pragma > (e.g. ExtraCommasLists) if there's a chance of ListSections (which would > conflict with this) becoming a reality. > >> Then your use case would work and also something like: >> >> abc = [ >> -- a >> , a >> -- b >> , b >> -- c >> , c >> ] > > I'd probably prefer leading-comma over trailing-comma style anyway (as > I've grown to like it over the years). > >> I think that are the main uses of additional commatas in literal lists >> and I can't see that someone really wants a list literal like '[,3,,4,]', >> so wrongly reading it as a list section shouldn't be an issue. > > Yeah, I don't care much about extra middle-commas either. Personally, > I'd be already happy with just trailing & leading extra-comma support. > _______________________________________________ > ghc-devs mailing list > ghc-devs@haskell.org > http://www.haskell.org/mailman/listinfo/ghc-devs _______________________________________________ ghc-devs mailing list ghc-devs@haskell.org http://www.haskell.org/mailman/listinfo/ghc-devs
