Re: RFC: ppath(3): property list paths library

[David Holland <dholland-tech%netbsd.org@localhost>]

On Mon, Nov 01, 2010 at 08:00:09PM -0500, David Young wrote:
 > I'm working on a library called ppath(3) for making property lists more
 > convenient to use in the kernel.  With ppath(3), you refer to a property
 > to read/write/delete in a property list by the path from the list's
 > outermost container.  Comments welcome.

Speaking from the POV of someone who's been working on querying
semistructured data for several years now... I have a pile of
high-level questions: (1) can you articulate the expressive power you
intend for your path expressions, and why that's a logical stopping
point vs. more expressive things; (2) what if any facilities do you
envision for checking paths against proplist schemas when/if we ever
manage to sort out a system for that; (3) what model do you have for
dealing with cases when the values found at the paths provided are not
what the user is expecting; and (4) what model do you have for dealing
with cases where the path does not name a single unique value or
position, if that's possible?

(I'm not trying to give you a hard time, I've just spent a long time
dealing with these problems and I don't want to see familiar mistakes
reinvented.)

-- 
David A. Holland
dholland%netbsd.org@localhost