[OSM-talk] No_comments=yes

Jochen Topf jochen at remote.org
Wed Feb 7 08:20:20 GMT 2007


On Wed, Feb 07, 2007 at 12:35:39AM +0000, Ben Robbins wrote:
> right.  I'm just being blunt.  I'm not anoyed particually, cause if knowbody 
> listens I'm quite content just making up my own rulesheet that works.
> 
> >>Bridge=yes and Tunnel=yes and all the other=yes.   Why are they keys not
> >>values?  Its not primary=yes, hamlet=yes, or parking=yes.  They have all
> >>been sorted into cleanly orgransied catagories.  I can understand why the
> >>_=yes excists, becuase somethings that seem alike will be needed together.
> >>(e.g. layers)  I think the method of putting yes/true after somethign is
> >>very messy though.
> 
> >Isn't messy when you consider some of the alternatives. Now we could 
> >happily
> >have something like something=bridge or something=tunnel instead, with the
> >minor problem that for the life of me I can't think up a generic enough 
> >word
> >for the key. You're completely screwed if you get a bridge which is also a
> >tunnel, but that doesn't happen very often. But it's specialised enough 
> >that
> >frankly it doesn't matter if there's a bridge=yes tag. What's a very bad
> >idea is degenerating the scheme to something like highway=primarybridge,
> >highway=footbridge -- it's a multiplicative expansion in the possible tag
> >values with no gain in expressiveness -- it just makes it hard to do
> >anything with programmatically.
> 
> Well the alternative is features=bridge, or structure=bridge.  Yes it could 
> be said it would be a problem if it is a bridge and a tunnel, but I think 
> examples where 2 things are in the same spot could be found for anything 
> somewhere in the world.  I think in those situations they can be tackled 
> seperatly because in 99.9% of all situations this wouldn't happen.   
> Highway=footbridge doesn't make sence because the highway would go over a 
> bridge.  The bridge in itself is not a highway.  This point also stands for 
> other highway tags that already exsists.

While in general I am all for having tag keys and value be created in
some logical way, sometimes it makes more sense to be just practical.
And words like "feature" and "structure" seem to be much too broad for
any kind of classification. They can apply to almost anything, so using
them here for bridges and tunnels doesn't really get us anywhere.

Here is a different suggestion going the other way: We could use the bridge
and tunnel keys for actually naming the bridge/tunnel. It is quite
common for bridges or tunnels to have names. Those names are distinct
from the names of the road which goes over the bridge or through the
tunnel. Currently there is no way to keep those apart. So I suggest
having

  bridge=Waterloo Bridge

or

  tunnel=Gotthardt Tunnel

This has the advantage of beeing backwards compatible. bridge/tunnel=yes
just gets the new meaning of "name unknown or non-existent".

Jochen
-- 
Jochen Topf  jochen at remote.org  http://www.remote.org/jochen/  +49-721-388298





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