[OSM-talk] Re: [OSM-dev] API 0.3 - Map call

Immanuel Scholz immanuel.scholz at gmx.de
Wed Mar 15 09:26:49 GMT 2006


We should remove the dev at openstreetmap.org. It seems easier to just
discuss everything in one list.

> Or even better as:
> <name>Maple Road</name>
> Namespaces should also be possible to allow extensions, for example:
> <opm:difficulty>blue</opm:difficulty>

Yes, this is done this way in other GIS systems. But OSM differs from
other systems that the keys are mostly not predefined but user strings,
which can contain any unicode crap.

We already had this discussion in the development list before. It turns
out that it is just not good to have user strings within the structure
(e.g. tag names).

It is NOT the idea of OSM to predefine an ontology and then force the
users to use this. That is the way which <insert here your favourite other
GIS system> goes.

>>       <tag k="scenery" >To the <i>north</i> you can see...</tag>

I don't like it very much. It makes parsers much more difficult to write
with little gain of human readibility (which is little important anyway).

The problem when parsing is, that with this, the plain list-structure of
the xml-data is lost. SAX-Parsers have to keep more internal state to
recognize in which hierarchy they currently are. Having a static hierarchy
is an advantage.

Think of something like this:

<tag k="foo"><tag k="bar">I am mean</tag></tag>

(This would be legal and interpreted as key="foo" value="<tag k="bar">I am

While speaking of readibility. Please change k to key and v to value in
API 0.4.

Ciao, Imi.

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