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Re: Encoding issue: missing elements same as nils?

From: Jacek Kopecky <jacek@systinet.com>
Date: Sat, 5 Jan 2002 20:44:28 +0100 (CET)
To: <xml-dist-app@w3.org>
Message-ID: <Pine.LNX.4.33.0201052041010.2787-100000@mail.idoox.com>
 Hello all. 8-)
 I just want to add in a different email that Systinet's position
is pro a) but we'll not object if the WG chooses b). We feel that
this issue needs to be clarified in the text of the spec though;
accepting either option leads to some rewriting of the text
quoted below (and possibly more).
 Best regards,

                   Jacek Kopecky

                   Senior Architect, Systinet (formerly Idoox)
                   http://www.systinet.com/



On Sat, 5 Jan 2002, Jacek Kopecky wrote:

 >  Hi, I was tasked by the ETF to formulate and send in the 
 > following issue:
 >  
 >  In SOAP Encoding in structures and in arrays, accessors can be 
 > omitted.
 >  The current WD says:
 >  (section 4.2, rule #9) "A NULL value or a default value MAY be
 > represented by omission of the accessor element. A NULL value MAY
 > also be indicated by an accessor element containing the attribute
 > xsi:nil with value '1 or true' [...]"
 >  (section 4.5) "An omitted accessor element implies either a
 > default value or that no value is known. The specifics depend on
 > the accessor, method, and its context."
 >  This text applies to both arrays and structs.
 > 
 >  The issue is: what does an omitted accessor really mean?
 >  There seem to be two options: 
 >  a) a NULL value equivalent to the situation of the accessor 
 > being present with xsi:nil set to true,
 >  b) a default value defined by the application.
 > 
 >  All other apparent options - null-or-default, 
 > complete-nothing-at-all etc. - are IMHO equivalent with b).
 > 
 >  Reasons for the two options, as I gather, are the following:
 > 
 >  pro a)	1: default or no values are usually represented by the 
 > language's NULL, which is not a first-class value.
 > 	2: simple handling 
 > 
 >  pro b)	1: able to distinguish between an explicit NULL and the 
 > default/unknown value.
 > 
 >  Best regards
 > 
 >                    Jacek Kopecky
 > 
 >                    Senior Architect, Systinet (formerly Idoox)
 >                    http://www.systinet.com/
 > 
 > 
 > 
 > 
 > 
 > 
Received on Saturday, 5 January 2002 14:44:30 GMT

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