Make some_elements() of products more interesting

[saraedum]

A common pattern used in doctests is

S = tester.some_elements()
M = cartesian product of S
for x,y in tester.some_elements(M):
    check things

Sometimes we need to set max_runs to make this product not get too big (especially if it is more than two copies of S involved.)

The current implementation of some_elemnts() then just takes the first few elements of the product. This is unfortunate because it means that we are not testing an interesting subset of the product.

Component: doctest coverage

Issue created by migration from https://trac.sagemath.org/ticket/23686

[tscrim]

comment:1

You want some magic code that can tell what objects are interesting. Instead you should just actually better use some_elements. I think the goal of this is impossible and there are tangible, good solutions. Thus we should close this as invalid.

[roed314]

comment:2

Travis and I had a discussion in person, resulting in #23724. I think we should return to this discussion after that ticket is resolved.