On Sat, Apr 16, 2011 at 02:21:05PM -0400, Aaron W. Hsu wrote:
> On Sat, 16 Apr 2011 09:59:00 -0400, Peter Bex <Peter.Bex@xs4all.nl> wrote:
>
> > The main practical problem is the question of what happens when multiple
> > quasiquotes are nested and unquoted.  This kind of thing tends to happen
> > mostly in (low-level) macros and other code-generating code.
>
> Indeed, this was something that R6RS, I believe, discussed explicitly as
> well, and I think the result was that nested quasiquotes were much well
> behaved in that standard.

Oh yes, I remember reading about that.  I liked the fact that r6 tried
to nail down the behaviour a bit more than r5, but I think the way nested
unquote was defined is a mistake:
http://lists.nongnu.org/archive/html/chicken-hackers/2010-12/msg00009.html

Others agreed with me, and it turned out the behaviour of other aspects
of quasiquote wasn't very consistent among R6RS implementations either:
http://lists.nongnu.org/archive/html/chicken-hackers/2010-12/msg00010.html

Cheers,
Peter Bex
--
http://sjamaan.ath.cx
--
"The process of preparing programs for a digital computer
 is especially attractive, not only because it can be economically
 and scientifically rewarding, but also because it can be an aesthetic
 experience much like composing poetry or music."
							-- Donald Knuth

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