In the discussion about continuation passing style, I forgot to explain
the semantics of when and how Guile discards extra return values. It's
very simple:
I wrote:
> Here's what (lambda () (list (f 1) (f 2) (f 3))) looks like in CPS,
> using the same evaluation order as I chose above:
>
> (lambda (outer-k)
> (f^ 2 (lambda (y)
> (f^ 1 (lambda (x)
> (f^ 3 (lambda (z)
> (list^ x y z outer-k))))))))
In the CPS examples, I modelled these normal "unary" continuations as
unary procedures of the form:
(lambda (x) ...)
In Guile, these "unary" continuations are not truly unary. Instead,
they can be modeled roughly as procedures of this form:
(lambda (x . _) ...)
Where '_' does not occur free in the body. So, to model Guile's
behavior in CPS, the example above becomes:
(lambda (outer-k)
(f^ 2 (lambda (y . _)
(f^ 1 (lambda (x . _)
(f^ 3 (lambda (z . _)
(list^ x y z outer-k))))))))
Mark
