On Sat, Aug 23, 2014 at 11:59 AM, John Cowan <xxxxxx@mercury.ccil.org> wrote:

In cooperation with Kevin Wortman, I've added set-cartesian-product
and set-power-set to the SRFI and the implementation, along with their
bag-* equivalents.

This sounds like last minute feature creep better

left to another SRFI, possibly with another approach

entirely.

Specifically I think because of the combinatorial

explosion in memory needed, such operations are

better served by a generating API than one which

returns a complete data structure, either as an

abstract generator or as a loop syntax extension.

Such an API should also include combinations and

permutations, as in Gauche's util.combinations[1]

library. See TAoCP Vol. 4a 7.2.1 for algorithms.

[1] http://practical-scheme.net/gauche/man/gauche-refe_199.html

Alex