[ht@inf.ed.ac.uk: Re: [xml-dev] RE: Schema vs Schema-free]

On xml-dev, Henry S. Thompson wrote:

> The W3C XML Schema Working Group is considering a proposal to add a
> datatype to the next version of W3C XML Schema which would distinguish
> e.g. 3.0 from 3.00 _as values_.  Reasoned statements of support or
> disagreement would be very welcome on www-xml-schema-comments@w3.org

I oppose this.  Mathematically, the numerals "3.0" and "3.00" are the same
thing, representations of the number 3.  People who make distinctions
between them are really trying to use using a single numeral to express
an *interval* value, most typically [2.95, 3.05) versus [2.995, 3.005).
(The [ marks an inclusive interval bound, the ) marks an exclusive one.)

What is worse, this convention works only for interval sizes less than 1.
There is no telling, given the numeral "1000", whether the intended
interval size is [500, 1450), [950, 1050), [995, 1005), or [999.5, 100.5).

Rather than supporting this hack, it would be more appropriate to add
proper support for intervals.  If people can convert their date data to
ISO 8601, they can convert their "significant figures" numbers to proper
interval values with a lower bound (inclusive or exclusive) and an upper
bound (inclusive or exclusive).

-- 
John Cowan  www.ccil.org/~cowan  jcowan@reutershealth.com  www.reutershealth.com
Monday we watch-a Firefly's house, but he no come out.  He wasn't home.
Tuesday we go to the ball game, but he fool us.  He no show up.  Wednesday he
go to the ball game, and we fool him.  We no show up.  Thursday was a
double-header.  Nobody show up.  Friday it rained all day.  There was no ball
game, so we stayed home and we listened to it on-a the radio.  --Chicolini

Received on Wednesday, 14 April 2004 17:13:25 UTC