Hello,

I am considering creating a revised, (mostly) backwards-compatible SRFI
113 that will align SRFI 113 with SRFI 146 (mappings).

The new features would be:

1. Make set-map and set-unfold have the same argument order as
hash-table-map and hash-table-unfold (PFN 2).
2. Add `set-ref` and `set-ref/default` with an API similar to SRFI 146.
`set-member` is deprecated.
3. Add `set-pop` with an API similar to SRFI 146.

(These are all repeated for the bag API.)

___________________________________________

There is one wrinkle. SRFI 113 allows an implementation to require
*either* a hash function *or* an ordering function. I believe that a
successor SRFI should make these sets “hash sets,” and leave ordering to
SRFI 153 (ordered sets) or a successor of it if needed.

-- Peter McGoron