proposal for trailing comma and semicolon

[Roman Cheplyaka]

I use them sometimes, but would do that much more if they didn't require
adding an extension.

Roman

* Edward Kmett <ekmett at gmail.com> [2013-05-17 15:24:27-0400]
> I personally use tuple sections a fair bit, though admittedly mostly for
> simple (,a) or (a,) cases.
> 
> 
> On Fri, May 17, 2013 at 3:01 PM, Ian Lynagh <ian at well-typed.com> wrote:
> 
> > On Fri, May 17, 2013 at 02:04:44PM -0400, Edward Kmett wrote:
> > > My main concern is its a really weird corner case for the grammar to
> > > remember for tuple sections and it does have very weird grammar
> > > specification issues.
> >
> > Tuple sections could look like
> >     (True, _)
> > rather than
> >     (True,)
> >
> > Does anyone know how common tuple sections are, incidentally? They've
> > been around since GHC 6.12, so it would be interesting to know if people
> > are actually using them.
> >
> > > I really have no objection to it for the other cases. It'd make export
> > > lists cleaner,
> >
> > Actually, you are already allowed an extra trailing comma in import and
> > export lists.
> >
> > > maybe a few other cases, but how often can you really say
> > > you can meaningfully comment out one field of a tuple have have the
> > > surrounding code make any sense?
> >
> > It happens occasionally, especially when simplifying code while
> > debugging.
> >
> > Commenting out list items is much more common, though.
> >
> > I'd be in favour of allowing a trailing or leading comma anywhere that
> > comma is used as a separator. TupleSections would need to be changed or
> > removed, though.
> >
> >
> > Thanks
> > Ian
> > --
> > Ian Lynagh, Haskell Consultant
> > Well-Typed LLP, http://www.well-typed.com/
> >
> >
> > _______________________________________________
> > Haskell-prime mailing list
> > Haskell-prime at haskell.org
> > http://www.haskell.org/mailman/listinfo/haskell-prime
> >

> _______________________________________________
> Haskell-prime mailing list
> Haskell-prime at haskell.org
> http://www.haskell.org/mailman/listinfo/haskell-prime