[geos-devel] WKT EMPTY

Artem Pavlenko artem at pavlenko.uklinux.net
Wed Apr 20 04:23:46 EDT 2005


Martin Davis wrote:

>Can't resist adding my 2c worth...
>
>To my mind, it's pretty clear that the intent of the syntax spec is that
>words in all UPPERCASE are intended to be literals in the WKT language.
>In this case, the representation of an empty Point is
>
>POINT EMPTY
>  
>
OK, but then POINTEMPTY is a valid expression as well.
Surely, it wasn't author intention?

>This interpretation also has the advantage of being unambiguous and
>explicit.  If the representation was POINT only, there are two
>interpretations:
>
>- an empty Point
>- an incorrect Point representation, with the actual coordinate missing
>  
>
Well, how about:

Point with coordinate missing == empty POINT
Always treat a 'POINT' as an empty one.  
  

>I guess the spec authors may have the final word, but until they weigh
>in I'd vote for sticking with POINT EMPTY.
>  
>
Who are the spec authors anyway?  Adam Gawne-Cain was involved in 
designing WKT/WKB when I used work at cadcorp. Is he the author?

I vote for POINT, LINESTRING, POLYGON etc.
It looks nicer!

Regards

Artem Pavlenko




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