Collin, is there some place where I should write-up how to transition
sort cmp functions?

Often, it is straight-forward to write a simpler key function, but
sometimes it isn't obvious how to proceed (i.e. cases that have an
ascending primary key and descentding secondary key or cases where a
user supplied cmp function is an unchangable, exposed part of the API).

I would like to issue some guidance on the subject.