geosparql

sparq-geosparql

sparq-geo is the OPT-IN GeoSPARQL 1.0/1.1 core for the sparq engine: it parses geo:wktLiteral and geo:gmlLiteral (the GML Simple-Features geometry profile) lexical forms, evaluates the geof: spatial functions, packages those functions as a sparq_engine::FunctionRegistry so they run inside real SPARQL FILTER/BIND/SELECT, and builds an R-tree GeoIndex over a sparq_core::Graph for distance/nearest/intersection queries. It is a separate crate so the core engine and the wasm build carry zero geometry code — you engage spatial support only by depending on sparq-geo.

Quickstart

Cargo.toml:

[dependencies]
sparq-geo    = { path = "../sparq-geo" }   # default features include `engine`
sparq-core   = { path = "../sparq-core" }
sparq-engine = { path = "../sparq-engine" }
geo-types    = "0.7"                        # only if you use GeoIndex (Point<f64>)

Run geof: functions inside a SPARQL query:

use sparq_core::Graph;
use sparq_engine::query_with_functions;
use sparq_geo::geof_registry;

let g = Graph::load_str(r#"
    @prefix geo: <http://www.opengis.net/ont/geosparql#> .
    <http://ex/london> <http://ex/loc> "POINT(-0.1278 51.5074)"^^geo:wktLiteral .
    <http://ex/paris>  <http://ex/loc> "POINT(2.3522 48.8566)"^^geo:wktLiteral .
"#, "turtle").unwrap();

let reg = geof_registry();               // 45 functions; clone-cheap, Send + Sync
let r = query_with_functions(&g,
    "PREFIX geof: <http://www.opengis.net/def/function/geosparql/>
     PREFIX uom:  <http://www.opengis.net/def/uom/OGC/1.0/>
     SELECT ?a ?b WHERE {
       ?a <http://ex/loc> ?ga . ?b <http://ex/loc> ?gb .
       FILTER(STR(?a) < STR(?b) && geof:distance(?ga, ?gb, uom:kilometre) < 400)
     }", &reg).unwrap();
assert_eq!(r.len(), 1);                   // London–Paris ≈ 343.6 km

POINT / WKT coordinates are longitude latitude (CRS84, the GeoSPARQL default). A leading <CRS-IRI> before the WKT selects a CRS; EPSG:4326 literals are LAT/LONG and are axis-swapped to internal long/lat on parse and back on output.