On Fri, Apr 22, 2011 at 7:46 AM, Andre van Tonder <andre@het.brown.edu> wrote:
> On Thu, 21 Apr 2011, Alex Shinn wrote:
>
>> On Wed, Apr 20, 2011 at 12:45 AM, Andre van Tonder <andre@het.brown.edu>
>> wrote:
>>>
>>> On Tue, 19 Apr 2011, Alex Shinn wrote:
>>>
>>>> We're getting lost in the details on the individual points, and
>>>> they pretty much all hinge on the one real question - are
>>>> imported values required to be the "same" binding in terms of
>>>> the syntax-rules pattern language?
>
> Yes, it must be the same binding.  Otherwise nested QUASIQUOTE will break.

If we don't explicitly require that they are the same binding,
and an implementation chooses to _not_ make them the
same binding, then it must come up with some way to make
quasiquote work.  It can choose to use the Chibi/Chicken
approach, or it can use a macro implementation which can
match the nested quasiquote with the actual identifier the
form was expanded from, or it can make quasiquote match
itself unhygienically.

My goal is not to prescribe what I think is the "best" approach.
My goal is to prescribe a standard that will

  1) allow as many implementations as possible to support it
  2) allow good implementations to implement their "best" approach
  3) minimize conflicts between approaches, and put the burden
      of bugfixes in these cases on the broken implementations
  4) wait for the real "best" approach to become a de-facto standard

This especially applies to the module system, which is the
first barrier to entry to R7RS support.  If they can get the modules
to basically work, they can contribute to a CPAN-like system
(which I intend to work on once the standard is finalized).

--
Alex

_______________________________________________
Scheme-reports mailing list
Scheme-reports@scheme-reports.org
http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports