[OSM-dev] Moving to stricter multipolygon parsing

[Peter Wendorff]

IMHO, and that's what most bothers me at the old interpretation of
multipolygons, any tag that belongs to a closed way should be valid for
that closed way.
We don't inherit names from streets to bus route relations - why should
we do so for names of polygons to multipolygons?

Therefore my interpretation is, and IMHO it's the most intuitive
interpretation, that the multipolygon relation describes "it's own"
geometry, by referring to other objects (!) geometries, where these
other objects may be features on their own or not.
That means: Tags that are used on an outer closed way of a multipolygon
relation should hold for the area enclosed by that way.
Tags that are used on  an outer non-closed way of a multipolygon
relation should hold for that way, which is not closed and doesn't get
more closed by other ways somehow related to it by a multipolygon.

For inner member ways it's basically the same.

This should IMHO not be dependent on any kind of tags (besides the
area=yes for closed ways where the closedness is not clearly implied by
other tags).

regards
Peter

Am 13.06.2014 16:10, schrieb Martin Koppenhoefer:
> 2014-06-13 1:25 GMT+02:00 Paul Norman <penorman at mac.com>:
> 
>> I think we need to move to a more strict parsing of MPs, accepting only
>> new-style MPs and old-style MPs where all outers have identical
>> non-deleted[2]
>> tags and the relation itself has no non-deleted tags.
>>
> 
> 
> +1
> 
> There is really only one usecase where I abuse the fuzziness of the old
> style: urban squares. While you often can't walk on all of their surface
> (e.g. there might be a fountain, a sculpture, buildings, green, etc. to
> exclude from highway pedestrian) the name will usually be for all of it.
> Adding only a name also doesn't solve it, because then it is not clear
> which kind of name it is (typology). This isn't really solved with old
> style MPs neither, of course, but at least this is less obvious and might
> be interpreted correctly by a human ;-)
> 
> 
> 
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