On Tue, Aug 30, 2011 at 3:26 AM, John Cowan <[email protected]> wrote: > > "It is an error" does not mean "an error is signalled". It's perfectly > fine for existing or future Schemes to store or output an undefined > value; it just isn't portable to do so. So it is not invasive and breaks > nothing except user code like > > (define x (set! y 32)) > > which has no portable meaning in any case (it will not work in Racket, e.g.).
Not true, as Eli pointed out. I'm unable to find a single implementation which does _not_ return a single unspecified value in these cases, despite the change in R6RS. -- Alex _______________________________________________ Scheme-reports mailing list [email protected] http://lists.scheme-reports.org/cgi-bin/mailman/listinfo/scheme-reports
