Alvaro Herrera <alvherre(at)commandprompt(dot)com> writes:
> In short, I think that while it is possible to define ranges of strings,
> it is not as useful as one would like.
Note it is not the *range* that is the problem, it is the assumption
that there's a unique "next" string. There's no unique next in the
reals or rationals either, but we have no problem considering intervals
over those sets.
regards, tom lane