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Re: Are literal language tags compared in lowercase?

From: Andy Seaborne <andy@apache.org>
Date: Thu, 12 Jan 2017 21:34:39 +0000
To: public-rdf-comments@w3.org
Message-ID: <d6592acc-0910-6284-1072-bd9e554620e2@apache.org>
By wanting to reflect what implementations RDF 1.1 ended up with "MAY be 
converted to lower case".  That weakens the position from RDF 1.0.

"Hello"@en and "Hello"@EN are the same value, and MAY be the same term. 
Term-equals is character-by-character on the lexical representations of 
language tags which MAY be converted to lower case.

	Andy

On 12/01/17 17:08, Eric Prud'hommeaux wrote:
> * Ivan Herman <ivan@w3.org> [2017-01-12 17:49+0100]
>>
>>> On 12 Jan 2017, at 17:44, Richard Cyganiak <richard@cyganiak.de> wrote:
>>>
>>>
>>>> On 12 Jan 2017, at 15:55, Stian Soiland-Reyes <soiland-reyes@cs.manchester.ac.uk> wrote:
>>>>
>>>> On Wed, 11 Jan 2017 19:00:47 +0000, Richard Cyganiak <richard@cyganiak.de> wrote:
>>>>> Hi Stian,
>>>>>
>>>>> An answer cannot be determined with 100% certainty from the text.
>>>>>
>>>>> What is clear:
>>>>>
>>>>> - "Hello"@en and "Hello"@EN have the same value
>>>>> - One MAY normalise "Hello"@EN to "Hello"@en
>>>>> - In RDF 2004, "Hello"@en and "Hello"@EN were clearly equal
>>>>>
>>>>> RDF 2004 forced the language tag to be lower-cased in the abstract syntax. Implementations of RDF 2004 often did not do that, but retained the case when storing or transforming RDF, while still treating @en and @EN as equal. My recollection is that we wanted to change the language of the spec to make this behaviour legal. Unfortunately it seems the language came out less clear than it should be. I do not think that there was any intention to make @en and @EN not equal.
>>>>
>>>> OK, so "Hello"@en and "Hello"@EN are the same value ("Value Equal"), but they are NOT (in RDF 1.1) "Term Equal”?
>>>
>>> That’s not what I said.
>>>
>>> In RDF 2004, "Hello"@en and "Hello"@EN were the same term (that is, they are equal).
>>>
>>> I don’t recall an intention to change that behaviour in RDF 1.1. So, as best as I can recall, the intention was that these two terms should still be the same term (that is, equal) in RDF 1.1.
>>>
>>
>>
>> That is certainly how I remember.
>
> A not uncommon implementation of this is to normalize to the first capitolization:
>
>   <Bob> <feeling> "ungry"@en-FR .
>   <Sue> <feeling> "ungry"@en-fr .
>
> SELECT ?who ?how { ?who <feeling> ?how }
>
>   | <Bob> | "ungry"@en-FR |
>   | <Sue> | "ungry"@en-FR |
>
>
>> Ivan
>>
>>
>>> Richard
>>>
>>>
>>>
>>>
>>>>
>>>> That would at least be along the same lines as "1"^^xsd:integer and "01"^^xsd:integer.
>>>>
>>>> --
>>>> Stian Soiland-Reyes
>>>>
>>>
>>>
>>
>>
>> ----
>> Ivan Herman, W3C
>> Digital Publishing Technical Lead
>> Home: http://www.w3.org/People/Ivan/
>> mobile: +31-641044153
>> ORCID ID: http://orcid.org/0000-0003-0782-2704
>>
>>
>>
>>
>
>
>
Received on Thursday, 12 January 2017 21:35:14 UTC

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