[geos-devel] GEOS Exceptions

Artem Pavlenko artem at pavlenko.uklinux.net
Tue Apr 19 06:39:19 EDT 2005


Hi strk,
I've coded a couple of tests:

data =  usa counties WKT 84Mb  3140 MULTIPOLYGONS (created like shp -> 
postgis -> wkt)
 
1.  GEOS  WKT  reader
     real    0m24.642s
     user    0m24.374s
     sys     0m0.235s

2. Mapnik WKT Reader
    real    0m15.651s
    user    0m15.215s
    sys     0m0.223s

It is not completely fair test, but shows that boost::spirit is fit the job.
Also new approach requires boost::spirit headers ( no libs ) and you get 
increase in compile time.
But, it is more elegant then 'StringTokenizer', easier to maintain (you 
can add more grammar later) and can be optimized even more.

What do you reckon? I can send you my test files?
How is GEOS development process organised?

Also, I've noticed that GEOS  using incorrect WKT grammar IMHO  e.g
POINT(EMPTY)????

OpenGIS Simple Features Specification rev1.1 EBNF:

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

According to ISO/IEC 14977 'EMPTY' means literally empty as far as I 
understand,
and valid WKT for point geometry: POINT  or POINT (x y)
The same applies to the rest.

Have you looked into that? Am i missing something?

Cheers!

Artem

 





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