Re: Issue: overlapping with XML Schema Part 2

[James Clark <jjc@jclark.com>]

Suppose you have

<restriction type="int">
   <pattern value="[0][0][0-9]+"/>
</restriction>

Clearly  "001" is allowed by this definition.  Is "1" also?

- If the answer is yes, then I don't know how to implement this.  This would
require that to check a string s you must determine whether there is a
string s' such that s' matches the pattern and s and s' denote the same
value.

- If the answer is no, then this is not a restriction on the value space,
because "1" and "001" correspond to the same value, but have one is allowed
and the other is not.

----- Original Message -----
From: "Kohsuke KAWAGUCHI" <kohsuke.kawaguchi@eng.sun.com>
To: <trex@lists.oasis-open.org>
Sent: Tuesday, May 08, 2001 7:19 AM
Subject: Re: Issue: overlapping with XML Schema Part 2

...
> 2. pattern (it says it applies to the value space, but I think this is
> unimplementable except for datatypes derived from string; the only way I
can
> see to implement it is to treat it as restricting the lexical space)

Actually, it says "pattern is a constraint on the value space of a
datatype which is achieved by constraining the lexical space." So I
don't see any flaw here.