Re: derivation by list

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

All the best, Ashok

"K.Kawaguchi" <> on 01/30/2001 10:46:41 PM

Sent by:

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


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

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

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 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
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.


Received on Wednesday, 31 January 2001 10:14:35 UTC