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Fuflillment of action item: language for circular includes

From: Amelia A Lewis <alewis@tibco.com>
Date: Fri, 05 Dec 2003 13:01:34 -0500
To: WS Description List <www-ws-desc@w3.org>
Message-id: <20031205130134.0f6c43cc.alewis@tibco.com>


In fulfillment of my action item to propose "spec-ese" permitting
circular includes, let me first quote from the XML Schema spec section
4.2.3 (which we reference):

NOTE: The above is carefully worded so that multiple <include>ing of the
same schema document will not constitute a violation of clause 2 of
Schema Properties Correct (\x{00A7}3.15.6), but applications are
allowed, indeed encouraged, to avoid <include>ing the same schema
document more than once to forestall the necessity of establishing
identity component by component.

The language of *our* specification, however, is not so "carefully
worded" (it *is* radically more comprehensible, on the other hand).

Therefore, rather than supplying a simple clarifying note (as WXS does,
above) highlighting the (possibly otherwise obscure) consequence of
circular includes, we ought to be more prescriptive.

Our section 4.1 contains an XML fragment (4.1-1), a general explanation
of the purpose of include paragraph (4.1-2), a discussion of the include
mechanism (4.1-3), and a description of the include EII (4.1-4).  This
is all followed by section 4.1.1.  I'm just numbering paragraphs here,
so I can state where the proposed addition is placed: between 4.1-3 and

Proposed text:

Multiple inclusion of a single WSDL document MUST be resolved to a
single set of components.  Mutual, multiple, and circular includes are
explicitly permitted, and do not represent multiple redefinitions of the
same components.  Processors are encouraged to keep track of the source
of component definitions, so that multiple, mutual, and circular
includes do not require establishing identity component-by-component.  A
mutual include is direct inclusion by one WSDL document of another WSDL
document which includes the first.  A circular include achieves the same
effect with greater indirection (WSDL A includes WSDL B includes WSDL A,
for instance).

Feedback solicited.

Amelia A. Lewis
Architect, TIBCO/Extensibility, Inc.
Received on Friday, 5 December 2003 13:11:29 UTC

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