Embed each concrete class in its leaf and type geometry arguments as Geo

example_types_io_test.go

@@ -37,6 +37,20 @@ func ExampleTGeomPointFromHexEWKB() {
 	// POINT(1 1)@2024-12-06 00:00:00+00 <nil>
 }
 
+func Example_sequenceAtGeometry() {
+	// A sequence carries the methods of its leaf, and a geometry argument is
+	// a *Geo: TGeomPointSeq reaches TPoint.AtGeom through TGeomPoint, whose
+	// restriction MEOS answers as a sequence set. It reads the value as
+	// #ExampleTGeomPointFromText does.
+	temp, _ := types.TGeomPointFromText("[Point(0 0)@2024-12-06, Point(2 0)@2024-12-08]")
+	seq := types.TGeomPointSeqFromPointer(temp.Pointer())
+	box, _ := types.GeometryFromText("Polygon((0 -1,1 -1,1 1,0 1,0 -1))", 0)
+	at, err := seq.AtGeom(&box.Geo)
+	fmt.Println(types.TGeomPointFromPointer(at.Pointer()), err)
+	// Output:
+	// {[POINT(0 0)@2024-12-06 00:00:00+00, POINT(1 0)@2024-12-07 00:00:00+00]} <nil>
+}
+
 func Example_cbufferString() {
 	cbuffer, _ := types.CbufferFromText("Cbuffer(Point(1 1),0.5)")
 	fmt.Println(cbuffer)

tools/objectgen.py

@@ -101,6 +101,11 @@ def zero(go_type: str) -> str:
     return "0"
 
 
+# The suffix a concrete class takes for each template subtype, as MEOS.NET's
+# tools/objectgen.py names them.
+SUBTYPE_SUFFIX = {"TInstant": "Inst", "TSequence": "Seq", "TSequenceSet": "SeqSet"}
+
+
 class Model:
     """The class hierarchy the catalog defines, indexed for emission."""
 
@@ -129,6 +134,16 @@ def _build(self) -> None:
             if cls:
                 self.parent[cls] = "Temporal"
 
+        # A concrete class is `<leaf><suffix>` and embeds its leaf, so it
+        # carries the leaf's family surface (TGeomPointSeq the methods of
+        # TGeomPoint), as #_build of MEOS.NET's tools/objectgen.py makes the
+        # leaf its base.
+        for leaf in [n for n, v in self.om["lattice"].items()
+                     if isinstance(v, dict) and v.get("kind") == "leaf"]:
+            for suffix in SUBTYPE_SUFFIX.values():
+                if leaf + suffix in self.om["classes"]:
+                    self.parent[leaf + suffix] = leaf
+
         for family in [k for k in self.om["companions"] if not k.startswith("_")]:
             for name, node in self.om["companions"][family]["nodes"].items():
                 if name.startswith("_"):