Re: [Chicken-hackers] PATCH: wrong type for alist-delete!

[Evan Hanson]

On 2016-01-14 16:10, John Cowan wrote:
> Evan Hanson scripsit:
> > Looks good to me. Debatably it ought to have an undefined return value,
> > as with typical destructive update procedures, but hey.
> 
> Not how linear-update works:  the !-less version is pure, the ! version is
> not pure (or at least may not be pure).  In any case, the data structure
> being changed is what is returned.  A number of SRFIs work like this.

Indeed, though that's not what the "!" convention means to me at first
glance. When I see a bang, I think guaranteed destructive update, not
linear-update. Of course, with lists you can't always do that, hence the
bangs and specified optionality.

IIRC there's some discussion of exactly this in the srfi-1 archives. I
just wish linear-update used a different naming convention.

Evan