Expand description
§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.
The entry points of this library are the two QueryResultsParser
and QueryResultsSerializer
structs.
Usage example converting a JSON result file into a TSV result file:
use sparesults::{QueryResultsFormat, QueryResultsParser, ReaderQueryResultsParserOutput, QueryResultsSerializer};
use std::io::Result;
fn convert_json_to_tsv(json_file: &[u8]) -> Result<Vec<u8>> {
let json_parser = QueryResultsParser::from_format(QueryResultsFormat::Json);
let tsv_serializer = QueryResultsSerializer::from_format(QueryResultsFormat::Tsv);
// We start to read the JSON file and see which kind of results it is
match json_parser.for_reader(json_file)? {
ReaderQueryResultsParserOutput::Boolean(value) => {
// it's a boolean result, we copy it in TSV to the output buffer
tsv_serializer.serialize_boolean_to_writer(Vec::new(), value)
},
ReaderQueryResultsParserOutput::Solutions(solutions_reader) => {
// 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 solutions_serializer = tsv_serializer.serialize_solutions_to_writer(Vec::new(), solutions_reader.variables().to_vec())?;
for solution in solutions_reader {
solutions_serializer.serialize(&solution?)?;
}
solutions_serializer.finish()
}
}
}
// Let's test with a boolean
assert_eq!(
convert_json_to_tsv(b"{\"boolean\":true}".as_slice()).unwrap(),
b"true"
);
// And with a set of solutions
assert_eq!(
convert_json_to_tsv(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.
Re-exports§
pub use crate::solution::QuerySolution;
Modules§
- solution
- Definition of
QuerySolution
structure and associated utility constructions.
Structs§
- Query
Results Parser - Parsers for SPARQL query results serialization formats.
- Query
Results Serializer - A serializer for SPARQL query results serialization formats.
- Query
Results Syntax Error - An error in the syntax of the parsed file.
- Reader
Solutions Parser - A streaming parser of a set of
QuerySolution
solutions. - Slice
Solutions Parser - A streaming parser of a set of
QuerySolution
solutions. - Text
Position - A position in a text i.e. a
line
number starting from 0, acolumn
number starting from 0 (in number of code points) and a global fileoffset
starting from 0 (in number of bytes). - Writer
Solutions Serializer - Allows writing query results into a
Write
implementation.
Enums§
- Query
Results Format - SPARQL query results serialization formats.
- Query
Results Parse Error - Error returned during SPARQL result formats format parsing.
- Reader
Query Results Parser Output - The reader for a given read of a results file.
- Slice
Query Results Parser Output - The reader for a given read of a results file.