Re: [HACKERS] Interval subtracting

Scott Marlowe wrote:
> On Wed, 2006-03-01 at 14:18, Bruce Momjian wrote:
> > Stephan Szabo wrote:
> > > > justify_days doesn't currently do anything with this result --- it
> > > > thinks its charter is only to reduce day components that are >= 30 days.
> > > > However, I think a good case could be made that it should normalize
> > > > negative days too; that is, the invariant on its result should be
> > > > 0 <= days < 30, not merely days < 30.
> > > 
> > > What about cases like interval '1 month -99 days', should that turn into
> > > interval '-3 mons +21 days' or '-2 mons -9 days'?
> > 
> > I think it should be the later.  It is best to have a single sign, and I
> > think it is possible in all cases:
> > 
> >     '2 mons -1 days'
> > 
> > could be adjusted to '1 mons 29 days'.
> 
> There's a part of me that thinks the WHOLE THING should be positive or
> negative:
> 
> -(2 months 1 day)

But it isn't '-2 months, -1 day'.  I think what you are saying is what I
am saying, that we should make the signs consistent.

--  Bruce Momjian   http://candle.pha.pa.us SRA OSS, Inc.   http://www.sraoss.com
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