[plt-scheme] Please help test version 359.100

My reading indicates they would both be legal.

What seems to be illegal is

  (for-each (lambda (x) (values x x)) (list 1))
  -->
  (values 1 1)

Robby

At Mon, 13 Nov 2006 21:39:11 -0500, Matthias Felleisen wrote:
> I don't think this is relevant. The true question is whether
> 
>   (+ (for-each add1 '()) (for-each sub1 '()))
> 
> steps to
> 
>   (+ some-value some-value)
> 
> or to
> 
>   (+ some-value some-different-value)
> 
> I believe that the second one is the case already. -- Matthias
> 
> 
> On Nov 13, 2006, at 6:52 PM, Jacob Matthews wrote:
> 
> > On Nov 13, 2006, at 5:31 PM, Robby Findler wrote:
> >
> >> Is "some object" allowed to be multiple values or not? That text
> >> suggests not.
> >
> > "Types are associated with values (also called objects) rather than  
> > with variables" (section 1.1) seems to be the only definition of  
> > what an 'object' is. I think it's clear that they are saying that  
> > values are also called objects, and that by the normal rules of  
> > English we can conclude that the singular 'object' means the same  
> > thing as the singular 'value'. So the question becomes, are  
> > multiple values the same thing as a single value?  The report seems  
> > to think not (I'm going here by the descriptions of the values and  
> > call-with-values functions in section 6.4), though it plays its  
> > usual trick of simply not defining what happens if a context  
> > expects a single value and it receives multiple ones.
> >
> > Applying this back to the original question, I think we have to  
> > conclude that for-each is supposed to be able to be called in  
> > contexts that expect exactly one value. In Schemes like PLT Scheme  
> > where contexts that expect one value signal an error if they  
> > receive some other number, then it's a violation of R5RS for for- 
> > each to behave the way 359.100 did; but for Schemes like Bigloo  
> > that have coercion rules that take a multi-value return to a single- 
> > value context, it's not a violation.
> >
> > -jacob
> >
> > (I actually wrote up a version of this before and then deleted it,  
> > thinking it was too technical for anybody to care about ... looks  
> > like I was wrong. :) )