[LV2] #name as identifier

Thomas Brand tom at trellis.ch
Sun Sep 25 07:21:21 PDT 2016

On Sun, September 25, 2016 01:12, David Robillard wrote:
> On Mon, 2016-09-19 at 23:27 +0200, Robin Gareus wrote:
>> On 09/19/2016 11:21 PM, Thomas Brand wrote:
>>> Hi,
>>> after a discussion on whether it can be useful to query properties by
>>>  name, i wondered about the authors' view on the following rephrasing
>>>  proposal of the LV2 specification for name
>>> http://lv2plug.in/ns/lv2core/#name :
>>> (additional text is enclosed like _new text_)
>>> A display name for labeling in a user interface. Unlike lv2:symbol
>>> this is unrestricted and may be translated. The lv2:name _is not
>>> necessarily unique in the scope of the plugin definition and
>>> therefore_ MUST NOT be used as a _unique_ identifier. This property is
>>> required for Ports, but MUST NOT be used by the host for _unique_ port
>>> identification. The plugin author may change the values of this
>>> property without changing the Plugin URI.
>> The proposed wording suggests that it may be OK to use name as
>> non-unique identifier. IMHO it only adds confusion to the previously well
>> written spec.
> Agreed.
> Labels (which is what this property should really be called) are not
> identifiers, regardless of adjective.  They aren't non-unique ones, they
> aren't unique ones, they aren't strong ones, they aren't weak ones, they
> aren't stable ones in any scope whatsoever no matter how narrow, etc.
> Using a label as an identifier in any way whatsoever is wrong, period.
> Any code that does so can and will break, and any such situation is, by
> definition, the fault of whoever wrote that broken code.
> This is true in general, though serializing/saving references to
> plugins/etc by name/label/etc is especially egregious.  Never, ever, ever
> do this, ever.
> There are numerous examples in the LAD world (and in general) of systems
> giving themselves serious long-term problems by confusing these things and
> not providing strong rules about canonical identifiers and the
> restrictions thereof.  LV2 very deliberately does not make this mistake,
> and is explicitly clear about what is, and what is not, an identifier.
> rdfs:label and lv2:name are very much not.
> --
> dr

.. and i was thinking it's a problem of definition of "identifier" but
obviously it sits deeper.


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