Sparesults

Sparesults is a set of parsers and serializers for SPARQL query results formats.

It supports SPARQL Query Results XML Format (Second Edition), SPARQL 1.1 Query Results JSON Format and SPARQL 1.1 Query Results CSV and TSV Formats.

Support for SPARQL-star is also available behind the rdf-star feature.

This crate is intended to be a building piece for SPARQL client and server implementations in Rust like Oxigraph.

Usage example converting a JSON result file into a TSV result file:

```rust use sparesults::{QueryResultsFormat, QueryResultsParser, QueryResultsReader, QueryResultsSerializer}; use std::io::Result;

fn convertjsontotsv(jsonfile: &[u8]) -> Result> { let jsonparser = QueryResultsParser::fromformat(QueryResultsFormat::Json); let tsvserializer = QueryResultsSerializer::fromformat(QueryResultsFormat::Tsv); // We start to read the JSON file and see which kind of results it is match jsonparser.readresults(jsonfile)? { QueryResultsReader::Boolean(value) => { // it's a boolean result, we copy it in TSV to the output buffer tsvserializer.writebooleanresult(Vec::new(), value) }, QueryResultsReader::Solutions(solutionsreader) => { // it's a set of solutions, we create a writer and we write to it while reading in streaming from the JSON file let mut solutionswriter = tsvserializer.solutionswriter(Vec::new(), solutionsreader.variables().tovec())?; for solution in solutionsreader { solutionswriter.write(&solution?)?; } solutions_writer.finish() } } }

// Let's test with a boolean asserteq!( convertjsontotsv(b"{\"boolean\":true}".as_slice()).unwrap(), b"true" );

// And with a set of solutions asserteq!( convertjsontotsv(b"{\"head\":{\"vars\":[\"foo\",\"bar\"]},\"results\":{\"bindings\":[{\"foo\":{\"type\":\"literal\",\"value\":\"test\"}}]}}".as_slice()).unwrap(), b"?foo\t?bar\n\"test\"\t\n" ); ```

License

This project is licensed under either of

• Apache License, Version 2.0, (LICENSE-APACHE or <http://www.apache.org/licenses/LICENSE-2.0>)
• MIT license (LICENSE-MIT or <http://opensource.org/licenses/MIT>)

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Oxigraph by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.