W3C home > Mailing lists > Public > www-xml-schema-comments@w3.org > January to March 2001

Re: derivation by list

From: Ashok Malhotra <petsa@us.ibm.com>
Date: Wed, 31 Jan 2001 10:14:20 -0500
To: "K.Kawaguchi" <k-kawa@bigfoot.com>
Cc: www-xml-schema-comments@w3.org
Message-ID: <OF8569373F.D72CB0DA-ON852569E5.0052DDAB@pok.ibm.com>

Please see my comments embedded in your note below.
They are prefixed by AM>>

All the best, Ashok


"K.Kawaguchi" <k-kawa@bigfoot.com>@w3.org on 01/30/2001 10:46:41 PM

Sent by:  www-xml-schema-comments-request@w3.org


To:   www-xml-schema-comments@w3.org
cc:
Subject:  derivation by list




Dear, XML Schema WG members,

I have a couple of questions about derivation by list

(1) What happens if itemType can legally have whitespaces as its lexical
    value?

Say

<simpleType name="foo">
  <restriction base="string">
    <enumeration value="abc def" />
    <enumeration value="ghi jkl" />
  </restriction>
</simpleType>

<simpleType name="bar">
  <list itemType="foo" />
</simpleType>

Should "abc def ghi jkl" be considered as a legal lexical value?
AM>> No.  The validator will consider this as a list with four
AM>> items.  Section 2.5.1.2 of the spec spells this out clearly.


(2) What is the point of allowing derivation of list type by list?
    How can the implementation distinguish inner-list from outer-list?
AM>> Lists cannot be derived from lists.  The spec says
AM>> "The value space of a list datatype is a set of finite-length
AM>> sequences of atomic values."

(3) In section 5.1.2, about the lexical space of list, the spec says

> whose lexical space is composed of white space separated lists of
> literals of the itemType.

But what is the formal definition of "white space" here? Is it just #x20
or one of the #x9,#xA,#xD, and #x20? Is multiple characters allowed or
not?
AM>> Whitespace refers to the four characters you name above.
AM>> Multiple whitespace characters are allowed but may be normalized
AM>> to a single whitespace character between items and no whitespace
AM>> before and after the list depending on the specification of the
AM>> whitespace facet.



regards,
----------------------
K.Kawaguchi
E-Mail: k-kawa@bigfoot.com
Received on Wednesday, 31 January 2001 10:14:35 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Sunday, 6 December 2009 18:12:49 GMT