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

[Tom Ellis]

On Sat, Aug 08, 2015 at 05:13:30PM -0400, Brandon Allbery wrote:
> On Sat, Aug 8, 2015 at 5:11 PM, Tom Ellis <
> tom-lists-haskell-cafe-2013 at jaguarpaw.co.uk> wrote:
> 
> > 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.
> 
> When did `data` start guaranteeing that the representation of a single
> constructor, strict `data' wrapper around another type is exactly the same
> as the wrapped type?

I make no claims about the operational semantics of existing compilers, but
can you point out a reason why data of a single strict field *shuoldn't* be
compiled in the same way as a newtype?