On Sun, Jun 13, 2010 at 6:05 AM, Steve Harris <steve@plugin.org.uk> wrote:

On 2010-06-13, at 00:20, fons@kokkinizita.net wrote:

> On Sun, Jun 13, 2010 at 12:09:12AM +0100, Steve Harris wrote:
>
>> On 2010-06-13, at 00:00, fons@kokkinizita.net wrote:
>>
>>> Half of the URLs quoted above refer to inexistent pages.
>>
>> That's bad karma, but not essential.
>>
>>> What is the purpose of 'http://' in that case ?
>>
>> They're just symbols.
>
> OK, let me rephrase the question: why are such ambiguous
> or misleading 'symbols' being used ?

Well, their hardly ambiguous. I would imagine that misleading-ness is somewhat dependent on your context.

If you don't feel comfortable with dereferencable symbols you could use schemes such as URN (http://en.wikipedia.org/wiki/Uniform_Resource_Name) which cannot be resolved, but it's missing some of the potential advantage.

http://www.w3.org/Addressing/

There are times when having the namespace be dereferencable is an advantage. If someone discovers a LV2 turtle file in the wild, but has no idea what LV2 is (this has happened) they can paste a URI into their web browser and discover more about it. I guess it's little different to googling the fingerprint of a binary data file you find, but it's much more reliable.

The remaining advantage is really just namespacing, but using an existing globally deployed, cheap, and well understood allocation scheme - the DNS system and HTTP paths.

I would like to add that as a beginner to LV2 plugins, I found the use of urls to be *extremely* confusing. In every other context that I have encountered a string beginning with "http://", it has been a direct reference to a web page or document existing at that URL. The implication with attaching "http://" is that the URL is synonymous with the file hosted there. However, in this case, the URL is not actually a resource locator, but a resource identifier. It was quite a shock when I found out that I identified plugins by a URL which didn't even have to exist, and when it did exist, it wasn't actually the plugin, but a website with autogenerated documentation. It is also confusing how both extensions and plugins use URLs.

If your goal is to have documentation easily accessible, then a line <docurl=http://blah> would serve the purpose just as well. The way it's currently set up, you have no idea if the URL is dereferenceable, or even supposed to be dereferenceable.

It probably would be a lot less confusing if URLs were used with a special prefix, like "lv2://blarg", because then it would be at least a bit more evident that the URLs are not supposed to be dereferenced by a web browser. This also would make things a lot nicer for plugin creators who don't own a website, because it is very confusing to choose a URL to something that you know you will never own, and especially confusing to create a URL that is just "bogus".

Anyway, I'm not saying you should change it, because it obviously works fine enough, and doesn't actually do anything harmful to the actual archetecture. I'm just saying that Fons is not alone in finding the URL naming scheme confusing. I'm sure it is confusing to most new lv2 users.

Jeremy