Discussion: getallfactors + getallsummands

[emerali]

@elisno brought up the question of whether we should give some sort of warning when calling getallfactors on KroneckerSum or getallsummands on AbstractKroneckerProduct as their behavior may be unexpected when dealing with mixtures of KroneckerProducts and KroneckerSums.

See the short discussion here: #66 (comment)

[MichielStock]

I think indeed a warning would be best. Though I would kind of see functions as getallsummands as low-level stuff needed internally but not really accessible to the user? Once you create a Kronecker product, it might not make much sense to pry out the individual matrices again?

P.S. Sorry for my very late response...

[emerali]

IMO it shouldn't warn because it's an internal method. It would be kind of annoying for the user to have to deal with these warnings every time the functions are called internally.

However, I think we could circumvent these issues (if we do decide to make the methods public) by having two functions getallsummands and _getallsummands, where the underscore function is used internally and doesn't ever throw warnings, while the other is user-facing and does warn. Not sure if this is the cleanest solution though.