Tobias Knerr wrote:
>/ Malcolm Herring wrote:
/>>/ My other wish is that disjunct outers be dis-allowed. Where multiple
/>>/ complete areas need to be associated, then this is the proper use of
/>>/ relations.
/
+1
>/ Why? How would you draw an administrative district with an exclave?
/
A relation for the administrative area with two area elements to
represent the territory, plus possibly a member for the capital and
whatever other members mappers come up with.
As we have relations for representing the relationship between elements,
I believe that we should design the area data type as a polygon (with
holes), not as a multipolygon. After all, it would be odd to have a
relationship between multiple areas as the one special case that works
without relations, while every other combination of elements uses relations.
So... a park with two parts separated by a railway? A city with exclave
(not administrative boundary, but place multipolygon now)? I live in
such city now, and I have that kind of park nearby. One can come up with
more examples, where multiple outer rings are needed.
Why should we restrict ourselves (adding extra tests to API by the way),
just to have to circumvent this restriction later with relations? Why
cannot administrative boundary relations be redefined to having an
entire area as a member, instead of working as a crippled multipolygon
for areas that were meant to replace multipolygon relations?
My opinion is that there is no much difference in having multiple versus
one outer rings: the processing is still the same, but there would be
less checks. And without a good reason to do that, I'm against
restricting areas to simple polygons with a single outer ring.
IZ
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