Re: Comments on Last-Call Working Draft of RDF 1.1 Concepts and Abstract Syntax

On 10/19/2013 11:40 PM, Sandro Hawke wrote:
>
> Pat Hayes <phayes@ihmc.us> wrote:
>> My 2c on these comments added inline.
>>
>> On Oct 19, 2013, at 4:46 PM, Michael Schneider wrote:
>>
>>> Dear Working Group!
>>>
>>> This is my review of the Last-Call Working Draft of the "RDF 1.1
>> Concepts and Abstract Syntax" specification.
>> [...]
>> * § 5.1: Several of the XML datatypes listed seem to be incompatible
>> with the definition of a "lexical-to-value mapping" in the beginning of
>> §5. According to the definition, "each member of the lexical space is
>> paired with exactly one value, and is a lexical representation of that
>> value. However, for example the lexical forms of the datatype
>> "xsd:time" do not uniquely denote a single time value, but denote an
>> infinite number of recurrent time values, one per day (for a fixed time
>> zone). Further, for the datatype "xsd:date", it is not clear whether a
>> lexical form denotes a single point on the timeline (e.g. the starting
>> point of a day), or rather a whole interval of values (the whole day).
>> Variants of these problems exist for several of the other listed
>> time-related datatypes.
>>
>> This is all very arguable. The text is however correct in describing
>> what RDF assumes about datatypes. This has some consequences for how
>> the XML datatypes must be interpreted. The value space of xsd:time is
>> the 24-hour daily clock, not timepoints on an infinite timeline. The
>> value space for xsd:date is either points or intervals (if you care,
>> ask the XMLSchema authors), but either way the value is required to be
>> unique for a given lexical form. Variants of these comments apply to
>> the other time-related datatypes.
>>
>> I propose that we make no changes in response to this comment. The
>> statement is accurate, and to get into this much detail is
>> inappropriate in Concepts.
>>
> I agree with you, but I know Michael has thought about this a lot.    I'd be more comfortable if we first asked him if there's a material reason we can't just think about it as you suggest here, Pat.    Given our current urgency, I think it would be best to ask asap.   I guess I'll take a crack at it in the morning (us/eastern) if you don't get to it first or say why we shouldn't.
>
> I might try to look up whether xsd is 1-1 (between values and canonical lex rep) first.
>
>       - Sandro
>
>
xsd:date values are intervals, so even though a single date contains lots of 
time points, it is a good a single value as any other.  I strongly suggest 
making no change here.

peter

Received on Sunday, 20 October 2013 21:39:36 UTC