On Sat, Apr 23, 2011 at 11:09:34PM -0400, Andre van Tonder wrote: > > It looks reasonable to me, but could you point us > > to the discussions or rationales? > > > > Specifically, how is (unquote-splicing a b c) different from > > ,@a ,@b ,@c ? > > I think the issue is a little more complex that this, it has to do with the > fact that nested unquote-splicing was accidentally broken in Scheme, but > since I > don't remember the details offhand, let me quote Al* Petrofsky on this issue.
Thank you for this rationale. I asked about the same issue before, but that part of my message was ignored. I considered the R6RS change rather unintuitive, but the case of unquoting to undo nested quoting levels for one spliced unquote makes sense. If this makes it into R7, I would like to see a rationale for this added. I looked for one in R6 and couldn't find it in there. I think this is necessary considering this is very strange behaviour: I compared it to implicit splicing of MV into the calling expression. It still feels like that to me, but at least now I understand why it's necessary or useful. PS: Andre, could you please consider not replying to an earlier message when posting a new, unrelated issue? This confuses mailclients with threading support because the in-reply-to header contains the message ID of the message you're replying to; this causes my mailclient to think all your messages of today belong to one giant thread :( It also messes up the archive's threaded view at http://lists.scheme-reports.org/pipermail/scheme-reports/2011-April/thread.html but the mailman software is broken in another way. Cheers, Peter -- 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 _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
