[r6rs-discuss] "Unspecified"

[AndrevanTonder]

On Mon, 2 Oct 2006, Sam TH wrote:

> It is true that `for-each/logging' doesn't work if the procedure
> argument sometimes returns multiple values (or zero values), and thus
> isn't always a drop-in replacement for `for-each'.  Many programs that
> take function arguments break in these cases - which was precisely my
> point.  We shouldn't make more special cases that have to be coded for,
> when we can allow the standard case to work.

It often has value for an error to be raised, however.  I can't say how many 
times I have found some mysterious #<void> entries in some data structure 
because the "standard case worked" even though it should not have.  If zero 
values were returned and an inappropriate number of values error had been 
raised immediately, such data structures could not even exist.  That would be a 
powerful gurantee.

Andre