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Re: ISSUE-134 (processing step clarification): Section 7.5, Step 11 Ambiguity in RDFa Core 1.1 [RDFa Core, Lite, and XTHML+RDFa CR comments]

From: Alex Milowski <alex@milowski.com>
Date: Wed, 25 Apr 2012 07:09:56 -0700
Message-ID: <CABp3FNLYWj5mkYQjGhm7BvoRSqSN81CNjeQS0k2WYBfMJRf2vw@mail.gmail.com>
To: RDF Web Applications Working Group <public-rdfa-wg@w3.org>
The problem is that the specification is in the English language and
not a programming language.  I wouldn't suggest, and did not in my
implementation, translate this verbatim into code.

As such, the sentence:

"otherwise, if the @rel, @rev, and @content attributes are not
present, as a resource obtained from one of the following:"

to me means that the current property value will be obtained from one
of the three subordinate clauses.  It doesn't if the attributes
@resource, @href, @src used in these clauses do not occur.  As stated,
there is no property value.

In Javascript, I actually implement them as a sequence of if/then/else
expressions like:

   !relAtt && !revAtt && !contentAtt && resourceAtt

where I test the other way around.

Something needs to be done to the clarify this.  My wording is only
one way to do that.

The editors have ultimate freedom to suggest better wording. :)

On Tue, Apr 24, 2012 at 8:50 PM, Grant Robertson <grantsr@gmail.com> wrote:
> Ivan, I don't know if I have a vote on this issue but:
>
> ABSTRACT:
> I don't think you need to modify the wording at all. If you do: Then, by
> that logic, you would have to modify many of the other steps in the
> specification which use the same "phraseology."
>
> ARGUMENT:
> The original sentence reads as follows:
>
> "otherwise, if the @rel, @rev, and @content attributes are not present, as a
> resource obtained from one of the following:"
>
> ... and then you proceed to list three things. By saying, "... from one of
> the following:" you are - in essence - specifying a switch statement. If
> none of the items in the list exist then that "otherwise," that switch
> statement, is not satisfied and the logic simply flows down to the next
> bullet item, a test for @typeof. One does not generally test for the
> presence of all possibilities within a switch statement before executing
> said switch statement. The switch statement itself does that testing for
> you.
>
> Now, I confess that I was also confused by this sentence at first (as can be
> seen by my highlighted question in the lower-right corner of the second
> table in
> http://lists.w3.org/Archives/Public/public-rdfa-wg/2012Apr/att-0013/RDFa_Sub
> ject-Object_Variables_Determination.pdf, posted previously).  However, upon
> one more reading of the sentence I have decided that it makes perfect sense,
> as is.
>
>
> If you were to make this change here - essentially accepting the notion that
> one should test for all conditions of a switch statement BEFORE actually
> executing said switch statement - then consistency would dictate that you
> also change many other steps within Section 7.5. For instance:
>
> Step 5.1 says, "... then new subject is set to the resource obtained from
> the first match from the following rule:" without specifying all the
> possible conditions within that same sentence. Nor does it specify what to
> do when none of the conditions are met. However, earlier in the spec it says
> that [new subject] is set to null. So an astute reader knows that if none of
> the conditions are met then nothing is done and [new subject] remains set to
> null.
>
> Later, Step 5.1 also says, "If @typeof is present then typed resource is set
> to the resource obtained from the first match from the following rules:" and
> then proceeds to list the exact same list of attributes - which concerned
> Alex Milowski in Step 11 - to check for in the subsequent bullet items. Now,
> in this situation, you also list an additional "otherwise" which creates a
> new bNode if none of the previous conditions are met. However, this also
> falls well within the standard paradigm of a switch or case statement in
> programming.
>
> There are many other examples. Sometimes no conditions are met and the logic
> "falls through" to the next step in the procedure and sometimes a default is
> listed as the last condition in the switch statement. In fact, within the
> specification, sometimes you "pre-test" for the switch conditions and
> sometimes you don't. But, again, there is never really a need for this
> "pre-test." However, to go through the entire specification and fix it so
> that all the processing steps are worded consistently would require many,
> many changes - whether we switched to using the pre-test in all such
> circumstances or whether we removed the pre-test from all the steps that
> currently include it. A large part of this procedure is composed of switch
> statements nested within switch statements. To insert a "pre-test" before
> each and every one of these would add considerable unnecessary bulk to the
> specification.
>
>
> CONCLUSION:
> Therefore, I highly-recommend that you DO NOT change the wording of this
> sentence.
>
>
>
> Grant S. Robertson
> www.demml.org
> www.ideationizing.com
>
>
>> -----Original Message-----
>> From: RDF Web Applications Working Group Issue Tracker
>> [mailto:sysbot+tracker@w3.org]
>> Sent: Monday, April 23, 2012 1:33 AM
>> To: public-rdfa-wg@w3.org
>> Subject: ISSUE-134 (processing step clarification): Section
>> 7.5, Step 11 Ambiguity in RDFa Core 1.1 [RDFa Core, Lite, and
>> XTHML+RDFa CR comments]
>>
>> ISSUE-134 (processing step clarification): Section 7.5, Step
>> 11 Ambiguity in RDFa Core 1.1 [RDFa Core, Lite, and
>> XTHML+RDFa CR comments]
>>
>> http://www.w3.org/2010/02/rdfa/track/issues/134
>>
>> Raised by: Ivan Herman
>> On product: RDFa Core, Lite, and XTHML+RDFa CR comments
>>
>> Raised on behalf of Alex Milowski, see his mail:
>>
>> http://www.w3.org/mid/CABp3FNJ9FWvWiBwYJp0ybEDuEC4430OuyrnTOmD
>> =UkQUzmLD6A@mail.gmail.com
>>
>> The request is to modify one of the clauses in the processing
>> step descriptions as follows:
>>
>> "if the @rel, @rev, and @content attributes are not present
>> and one of @resource, @href, or @src are present, as a
>> resource obtained from one of the following:"
>>
>>
>>
>
>



-- 
--Alex Milowski
"The excellence of grammar as a guide is proportional to the paucity of the
inflexions, i.e. to the degree of analysis effected by the language
considered."

Bertrand Russell in a footnote of Principles of Mathematics
Received on Wednesday, 25 April 2012 14:10:31 GMT

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