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empty intervals Per Bothner (29 Jul 2015 16:44 UTC)
Re: empty intervals John Cowan (29 Jul 2015 17:12 UTC)
Re: empty intervals John Cowan (29 Jul 2015 17:16 UTC)
Re: empty intervals Bradley Lucier (29 Jul 2015 20:21 UTC)
Re: empty intervals Per Bothner (29 Jul 2015 20:56 UTC)
Re: empty intervals Bradley Lucier (29 Jul 2015 22:02 UTC)
Re: empty intervals Per Bothner (29 Jul 2015 23:36 UTC)
Re: empty intervals John Cowan (01 Aug 2015 03:52 UTC)
Re: empty intervals Bradley Lucier (01 Aug 2015 03:57 UTC)
Re: empty intervals Bradley Lucier (31 Jul 2015 20:49 UTC)
Re: empty intervals Per Bothner (31 Jul 2015 22:14 UTC)
Re: empty intervals John Cowan (31 Jul 2015 23:57 UTC)
Re: empty intervals John Cowan (31 Jul 2015 23:37 UTC)
Re: empty intervals Bradley Lucier (01 Aug 2015 02:00 UTC)
Re: empty intervals John Cowan (29 Jul 2015 21:11 UTC)
Re: empty intervals Bradley Lucier (29 Jul 2015 22:27 UTC)
Re: empty intervals John Cowan (01 Aug 2015 04:20 UTC)

Re: empty intervals John Cowan 31 Jul 2015 23:57 UTC

Per Bothner scripsit:

> (1) This case
> (= (interval-lower-bound I i) (interval-upper-bound I i))
> This needs to be allowed, no ifs or buts, and the specification
> needs to say so.

I agree.  That allows arrays to be empty.  Only very C-ish languages
prohibit empty arrays, and not for any very good reason (gcc allows them).

> (2) This case:
> (= (interval-dimension I) 0)
> I don't feel as strongly about, though it would be allowed in any
> implementation I control. I think there is no good reason to not
> allow it, and good reasons (consistency, generality) to allow it.

I think it should be required to be true for consistency and generality.

--
John Cowan          http://www.ccil.org/~cowan        xxxxxx@ccil.org
Do what you will / this Life's a Fiction
And is made up of / Contradiction.  --William Blake