[scheme-reports-wg1] Re: [Scheme-reports] Return value for unmatched cond-expand

[John Cowan <cowan@x>]

[Copying the WG1 list on this point.]

Christian Stigen Larsen scripsit:

> Draft 8 does not say whether the return value for an unmatched cond-expand
> is unspecified.

You're right, and it's All My Fault, but it's probably too late now.

The winning proposal was CondExpandCowan, which was cloned from SRFI 0.
In SRFI 0, falling off the end of a cond-expand is an error, and I
meant to clone that feature into my proposal, but didn't.  That's not
a big problem for the cond-expand macro, because you can add your own
else clause.  In the cond-expand library declaration, however, it's
another story, as there is no explicit way to signal an error from
library expansion.  Chibi simply ignores the whole cond-expand in that
case, which is not perhaps the best thing.

>     "[...] Otherwise, the cond-expand has no effect. Unlike cond,
>     cond-expand does not depend on the value of any variables."

Without a vote, we can't override the previous vote.  I do not feel
inclined to call for such a vote myself at this point, though other WG
members may feel differently.

-- 
Yes, chili in the eye is bad, but so is your    John Cowan
ear.  However, I would suggest you wash your    cowan@x
hands thoroughly before going to the toilet.    http://www.ccil.org/~cowan
        --gadicath