[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Scheme-reports] multiple values module
7 minutes ago, Eli Barzilay wrote:
> 7 hours ago, Aaron W. Hsu wrote:
> > On Wed, 25 May 2011 11:07:25 -0400, Eli Barzilay <eli@x> wrote:
> > > 15 minutes ago, Alex Shinn wrote:
> > >>
> > >> It was known behavior, left in place mostly because I didn't
> > >> actually care Any Scheme that behaves like Chibi in this case can
> > >> be fixed with: [...] The actual fix in Chibi was just one line,
> > >> [...]
> > > The question is still open, AFAICT: is the pre-fix problem something
> > > that is fine to have in an r5/7rs? According to John, your bug fix
> > > was not needed.
> > From my reading of the R5RS, I concur with John that the original
> > behavior of Chibi was not breaking compliance with the standard.
> > That is, R5RS and R6RS both allow implementations to do *whatever*
> > they want if a continuation expecting a single value receives more
> > than one value.
> That's *not* the chibi problem that I talked about. To repeat:
> (lambda ()
> (call-with-current-continuation (lambda (k) (k 1 2 3))))
> (lambda (x y z) 'ok))
> the problem here is that the `k' continuation is one that expects
> three values, and it is given three values.
..., and chibi still raised an error.
> According to John, that's valid r5rs-ims.
> The other issues (sending different number of values to a cont.,
> reifying values, and even reifying them as a list) are things that I
> argued are bad (to varying degrees, the last being particularly bad),
> but I'm aware of them being allowed. (Specifically, chicken's thing
> of dropping values or making unspecified ones up are likely to be
> common, since it's roughly the same as in CL.)
((lambda (x) (x x)) (lambda (x) (x x))) Eli Barzilay:
http://barzilay.org/ Maze is Life!
Scheme-reports mailing list