Taylan Ulrich Bayırlı/Kammer scripsit:

> I got the idea from MIT/GNU Scheme, and just realized that it actually
> just applies to eqv? hash tables there, which makes sense.  I'll adopt
> that.

Okay, that makes sense.

> > Ephemerons are inherently key-weak: I don't think it makes sense to have
> > ephemeral-value or ephemeral-value-and-key.  So just use ephemeral-key
> > (which could be shortened to ephemeral) and explain that ephemeral tables
> > can be used in place of key-weak ones if the implementation sees fit.
>
> See MIT/GNU Scheme.  An ephemeral-value table simply swaps the position
> of the key/value in the ephemerons held by the table (but the key is
> still the key for the hash table).  In key & value, there is a pair of
> ephemerons.

The former makes sense operationally if not in human terms (what is it for?).
The latter is just confusing.  I'll look at the MIT Scheme docs.

> I really wish R7RS had not reverted that change but anyhow, since this
> is for R7RS, you're right.

All known R6RS implementations return a single unspecified value anyway;
it was extending a latitude that nobody used.

> After pondering on this and asking a couple people for their opinion, I
> decided to adopt `hashtable-map!` for that use-case instead.

Good idea.

--
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as in this case.  In general, the quotes are chosen at random by a script
from <http://www.ccil.org/~cowan/signatures>, but sometimes I choose one
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