{
  "name": "extrude",
  "type": "function",
  "description": "Returns an extruded version of the input (Multi-)Curve or (Multi-)Linestring geometry with an extension specified by x and y.",
  "arguments": [
    {"arg":"geom","description":"a polygon geometry"},
    {"arg":"x","description":"x extension, numeric value"},
    {"arg":"y","description":"y extension, numeric value"}
  ],
  "examples": [
    {
      "expression":"extrude(geom_from_wkt('LineString(1 2, 3 2, 4 3)'), 1, 2)",
      "returns":"Polygon ((1 2, 3 2, 4 3, 5 5, 4 4, 2 4, 1 2))"
    },
    {
      "expression":"extrude(geom_from_wkt('MultiLineString((1 2, 3 2), (4 3, 8 3)'), 1, 2)",
      "returns":"MultiPolygon (((1 2, 3 2, 4 4, 2 4, 1 2)),((4 3, 8 3, 9 5, 5 5, 4 3)))"
    }
  ]
}