On Fri, 18 Apr 2008, Andy Allan wrote:
> Ah, I see the problem. You are taking a tag away from it's context,
> and then complaining that the tag has no context on its own. Only part
> of your argument is based around conflicts, but the rest seems to be
> context.
Yes, it's a bit of both - I think these are two separate problems with the
flat name space.
> How do I tell that name="The Duke's Head" refers to the name of a pub?
> I don't feel the need for amenity:pub:name= and highway:primary:name=
> in order to solve this issue. Instead, I examine the context of the
> original tag, and find that it is the name of a pub.
Actually, I would prefer to see everything namespaced, such as
amenity:pub:name or pub:name. But clearly that isn't going to happen any
time soon.
In my ideal world, the editors would allow the user to attach a
hiararchical tree of tags to an object, which would do a wonderful job of
identifying the exact context of each tag. :)
> This is where
> people run into problems on the wiki - you can't explain the meaning
> of the tag "capacity" in its own right, but you can in the context of
> car parks, bike parking, football stadiums and ski lifts.
The wiki problem would, of course, be fixed if all tags were prefixed with
the appropriate name space :)
> But this is still not an argument
> for namespaces, when we have other options (yes, relations) available
But relations are even more complex for people to understand and use than
namespaces (which seems to be one of the primary arguments against
namespaces)...
> So in summary, I think the "need" for namespaces is driven purely by
> people who want to view a tag in isolation yet still want to have
> context, when what they should do is not remove the context in the
> first place.
Part of the problem is that you need prior knowledge as to where the
context comes from. OSM treats all tags as equals, but in reality they
aren't - for example, a "highway=motorway" tag immediately defines the
context for all the other tags as being something to do with motorways.
"amenity=pub" defines the context for all the other tags as being
something to do with pubs. But "name=Station Road" or "ref=M4" doesn't
really change the context. Without having prior knowledge about which
tags are defining the context, and which are just providing data, it is
sometimes quite ambiguous where the context comes from. On the other
hand, a clear namespace such as "highway:motorway:ref=M4" makes it
immediately clear what the context is. This makes it easier to do
something like look up a tag in the wiki, to work out what it means.
- Steve
xmpp:[EMAIL PROTECTED] sip:[EMAIL PROTECTED] http://www.nexusuk.org/
Servatis a periculum, servatis a maleficum - Whisper, Evanescence
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