[geos-devel] GEOS Exceptions

strk at refractions.net strk at refractions.net
Tue Apr 19 09:41:53 EDT 2005

On Tue, Apr 19, 2005 at 02:33:16PM +0100, Artem Pavlenko wrote:
> Hi Frank
> I think EMPTY means literaly empty
> have a look at http://www.cl.cam.ac.uk/%7Emgk25/iso-14977.pdf

Actually, reading the grammar in OGC SFS 1.1 it doesn't look as
EMPTY has a special meaning:

<Point Tagged Text> :=
           POINT <Point Text>

<Point Text> := EMPTY | ( <Point> )

<Point> := <x> <y>

<x> := double precision literal
<y> := double precision literal

Things with special meaning are wrapped in <> brackets or lowercase
so that would be a <Empty> or 'empty sequence'.
EMPTY looks like POINT, which is verbatim.


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