[postgis-devel] multisurface definition in bnf-wkt.txt

[Mateusz Łoskot]

Hi,

The bnf-wkt.txt [1], with last commit saying "Document ISO WKT/WKB (#1451)"
specifies:

<multisurface text representation> ::=
    MULTISURFACE [ <z m> ] <multisurface text> |
    <multipolygon text representation> |
    <polyhedralsurface text representation> |
    <tin text representation>

whereas the ISO/IEC 13249-3 (Date: 2009-01-16) specifies:

<multisurface text representation> ::=
     MULTISURFACE [ <z m> ] <multisurface text>
   | <multipolygon text representation>

<multisurface text> ::=
     <empty set>
   | <left paren> <surface text>
      { <comma> <surface text> }... <right paren>

<surface text> ::=
     CURVEPOLYGON <curvepolygon text body>
   | <polygon text body>


Why bnf-wkt.txt adds polyhedralsurface and tin to
multisurface text representation?
Is that PostGIS-specific behaviour?

[1] https://github.com/postgis/postgis/blob/svn-trunk/doc/bnf-wkt.txt

Best regards,
--
Mateusz  Łoskot, http://mateusz.loskot.net