val rings : t -> LineString.t arrayrings t returns the linear rings contained in t (a Polygon object)
val exterior_ring : t -> LineString.texterior_ring t returns the first linear ring contained in t (a Polygon object). This ring bounds the surface
val interior_rings : t -> LineString.t arrayIf t (a Polygon object) contains more than 1 linear ring, interior_rings t returns the rest of the linear rings apart from the first. These rings (if present), bound the holes.
val v : LineString.t array -> tCreate a polygon object from an array of close line strings (note no checking is down here to ensure the loops are indeed closed.)
val to_positions : t -> Position.t array arrayConvert directly to the positions that make up the lines.
val of_positions : Position.t array array -> tConvert directly from positions to lines