Another thing I'm a little confused by is the precise API for the in_range
support functions (the lack of any documentation for it doesn't help).
I wonder why you chose to provide two support functions per datatype
combination rather than one with an additional boolean argument.
In fact, it almost seems like the "end" flag could already do the
job, though I may be missing something. As-is, it seems like this
setup involves a lot of duplicate code and catalog entries ... what
are we gaining from that?
regards, tom lane