On 03/02/21 13:01, Mark Dilger wrote: > The problem is not just with lower() and upper(), but with equality testing > (mentioned upthread), since code may rely on two different "positions" > (your word) both being equal, and both sorting the same.
Could those concerns be addressed perhaps, not by adding an entirely new just-like-a-range-but-remembers-position-when-zero-width type (which would feel wartlike to me), but by tweaking ranges to /secretly/ remember the position when zero width? Secretly, in the sense that upper(), lower(), and the default sort operator would keep their established behavior, but new functions like upper_or_pos(), lower_or_pos() would return the non-NULL value even for an empty range, and another sort operator could be provided for use when one wants the ordering to reflect it? Regards, -Chap
