Not exactly,

The definition of values given by the spec is: The R5RS's definition of values:

(define (values . things) (call-with-current-continuation (lambda (cont) (apply cont things))))

Let's say you can have 2 types of continuations:

1. Single value continuations 2. multi-value continuations.

If the current continuation is a single value continuation, then only return one value, otherwise for a multi-value continuation (created with call-with-values) send all the arguments. The behavior could then be like:

(define (values . things) (call-with-current-continuation (lambda (cont) (if (mv-continuation? cont) (apply cont things) (apply cont (car things) '())))))

In the case of (values), I'd leave that unspecified.

Arthur

----- Original Message ---- From: Bradley Lucier lucier@math.purdue.edu To: Arthur Smyles atsmyles@earthlink.net Cc: Bradley Lucier lucier@math.purdue.edu; Marc Feeley feeley@iro.umontreal.ca; gambit-list@iro.umontreal.ca Sent: Monday, September 22, 2008 11:35:51 AM Subject: Re: [gambit-list] strange results using values

It sound like you want every place in the program that takes a value to check whether there are more than one value returned, and pick the "primary" one.

So if you have

(define (f a b) (+ a b))

(define (g a b) (values a b))

(f (g 0 1) 2)

you'd want the code to f to check that g returned only a single value, strip out extra ones if it returned more than 1, perhaps signal an error if g didn't return any values, do something else?

Common Lisp deals with this somehow, but I'm not sure that we want the semantics of values in Scheme to be complicated so much in able to implement such a proposal.

Brad