Programming challenge: wildcard exclusion in cartesian products

[Doug Quale]

"funkyj" <funkyj at gmail.com> writes:

> One advantage of a generator over filtering the full product is that I,
> as the user of the generator, am not obligated to iterate over the
> entire solution space.
> 
> Are there other _practical_ advantages of generators over mapping &
> filtering complete sets?

Storage.  You can iterate over problem spaces much too large to fit in
memory.  Also generate + iterate can be faster because of reduced
memory pressure.