[Haskell-cafe] an idea for modifiyng data/newtype syntax: use `::=` instead of `=`

[Tom Ellis]

On Sat, Aug 08, 2015 at 11:14:40PM +0200, MigMit wrote:
> > On 08 Aug 2015, at 23:11, Tom Ellis <tom-lists-haskell-cafe-2013 at jaguarpaw.co.uk> wrote:
> > 
> > On Sat, Aug 08, 2015 at 11:02:27PM +0200, MigMit wrote:
> >> What you say is "if we don't use some perfectly legitimate language
> >> constructs and never use third-party code, than 'data' and 'newtype' are
> >> the same".
> > 
> > No, not at all.  I'm making a much stronger claim than that.  I'm claiming
> > the functionality provided by newtype is completely subsumed by that
> > provided by data.
> 
> Well, it's certainly unsupported by evidence. Because third-party code CAN
> distinguish between those.

OK, show me the code!