Mike Sperber wrote: > > (append '() '(a) '()) > > The intention was, that, in this case, append does not construct a > nonempty chain of pairs, therefore nothing needs to be newly allocated.
Are you sure? That would be a change from IEEE/ANSI/R5RS semantics, and it was indeed proposed, but according to Kent Dybvig's summary dated 2 May 2006, the editors' vote on that proposed change was 2-3, so the proposal failed [1]. Unless that vote was overturned later (and I have not found any evidence of that), (append '() '(a) '()) should still return a newly allocated list. As further evidence for that interpretation, R6RS Appendix E does not mention any change in the semantics of append. > I agree it's a bit confusing - if you can suggest a better wording, I'd > be happy to add an erratum. If the proposed change in semantics was never approved by the R6RS editors, then why not use the R5RS wording? Will [1] http://www.r6rs.org/r6rs-editors/2006-May/001205.html _______________________________________________ r6rs-discuss mailing list [email protected] http://lists.r6rs.org/cgi-bin/mailman/listinfo/r6rs-discuss
