Status of Haskell'?

[Ross Paterson]

On Fri, Nov 30, 2012 at 11:05:41PM +0000, Gábor Lehel wrote:
> Well, I'm not so sure it's a great idea to just bake "what GHC does at
> this moment" (for any particular extension) into the standard without
> really thinking about it. Even then, you have to figure out, in great
> detail, what GHC does, and write it all down! That's not negligible
> effort, either.

And that is the core of the problem.  The standard isn't just a list
of approved features.  It needs to describe them in such detail that a
programmer can tell, from the Report alone, whether a particular program
is legal, and if so what it's supposed to do.  We don't have that level
of description for these extensions, and creating it will be a lot of
hard work.

Relying on "what GHC does at the moment" has obvious risks for
programmers, it also puts an unfair responsibility on GHC itself.  How can
they improve a feature if it's current implementation is the "standard"?