ENVELOPE() in CQL

[cportele]

The definition of ENVELOPE in the CQL BNF is

envelopeText = leftParen westBoundLon comma eastBoundLon comma northBoundLat comma southBoundLat [comma minElev comma maxElev] rightParen;

This is a pretty weird sequence with a convention that I haven't seen yet: west, east, north, south, low, high (low/high optional). I checked CSW and it is the same there.

@pvretano @aaime: Is this really what has been implemented in the existing CQL implementations?

I would have expected west, south, low, east, north, high (same as bbox). Or at least west, east, south, north, low, high.

[pvretano]

@cportele I picked it up from trom CSW but I would not be opposed to aligning it with bbox since it would be consistent across APIs and encodings.

[aaime]

@cportele in GeoTools we don't have a BNF but a javacc grammar, here it is, with specific reference to the ENVELOPE support:

https://github.com/geotools/geotools/blob/74c043ac69918ac4d7c3a6498f287fc66d223a97/modules/library/cql/src/main/jjtree/ECQLGrammar.jjt#L1272

TBH I have never used ENVELOPE before, to do bounding box intersection tests we have a dedicated BBOX operator.

[cportele]

@aaime - I see, the grammar has also west/east/north/south, but the test at

https://github.com/geotools/geotools/blob/master/modules/library/cql/src/test/java/org/geotools/filter/text/cql2/CQLLiteralTest.java#L155

seems to imply west, east, south, north and the text in

https://docs.geoserver.org/latest/en/user/filter/ecql_reference.html

also states ENVELOPE ( x1 x2 y1 y2 ).

I see the BBOX() predicate in your ECQL, but I don't think that is in CQL.

[cportele]

2020-07-20: Change to west, south, [low], east, north, [high], consistent with bbox in Features Part 1.