Re: Combining float/string to specify value/units

[Rick Jelliffe <ricko@allette.com.au>]

From: Steve Rosenberry <steve.rosenberry@verizon.net>
 
> Is the validation of primitive datatypes built into validators
> and not dependent upon a second XML Schema declaration?

Yes.  And not just the "primitive" datatypes, but also the 
"built-in derived types" as well.

There is a "Schema for Schemas" in the proposed recommendation.
But you should not expect schema processors to use it explicitly:
it is the schema that is built-in to a schema processors.  

A schema processor checks more than just whether some data
conforms to regular expression. While datatypes do have such 
"lexical spaces" they also have "value spaces", where a number
is checked as a number.  (Because of these value spaces, one cannot
really bootstrap an XML Schema implementation very nicely
from string-matching-only primitives.)

Cheers
Rick Jelliffe