Struct QueryResultsParser

Source

pub struct QueryResultsParser { /* private fields */ }

Expand description

Parsers for SPARQL query results serialization formats.

It currently supports the following formats:

Example in JSON (the API is the same for XML and TSV):

use sparesults::{QueryResultsFormat, QueryResultsParser, ReaderQueryResultsParserOutput};
use oxrdf::{Literal, Variable};

let json_parser = QueryResultsParser::from_format(QueryResultsFormat::Json);
// boolean
if let ReaderQueryResultsParserOutput::Boolean(v) = json_parser.clone().for_reader(br#"{"boolean":true}"#.as_slice())? {
    assert_eq!(v, true);
}
// solutions
if let ReaderQueryResultsParserOutput::Solutions(solutions) = json_parser.for_reader(br#"{"head":{"vars":["foo","bar"]},"results":{"bindings":[{"foo":{"type":"literal","value":"test"}}]}}"#.as_slice())? {
    assert_eq!(solutions.variables(), &[Variable::new("foo")?, Variable::new("bar")?]);
    for solution in solutions {
        assert_eq!(solution?.iter().collect::<Vec<_>>(), vec![(&Variable::new("foo")?, &Literal::from("test").into())]);
    }
}

Implementations§

Source §

impl QueryResultsParser

Source

pub fn from_format(format: QueryResultsFormat) -> Self

Builds a parser for the given format.

Source

pub fn for_reader<R: Read>( self, reader: R, ) -> Result<ReaderQueryResultsParserOutput<R>, QueryResultsParseError>

Reads a result file from a Read implementation.

Reads are automatically buffered.

Example in XML (the API is the same for JSON and TSV):

use sparesults::{QueryResultsFormat, QueryResultsParser, ReaderQueryResultsParserOutput};
use oxrdf::{Literal, Variable};

let xml_parser = QueryResultsParser::from_format(QueryResultsFormat::Xml);

// boolean
if let ReaderQueryResultsParserOutput::Boolean(v) = xml_parser.clone().for_reader(br#"<sparql xmlns="http://www.w3.org/2005/sparql-results#"><head/><boolean>true</boolean></sparql>"#.as_slice())? {
    assert_eq!(v, true);
}

// solutions
if let ReaderQueryResultsParserOutput::Solutions(solutions) = xml_parser.for_reader(br#"<sparql xmlns="http://www.w3.org/2005/sparql-results#"><head><variable name="foo"/><variable name="bar"/></head><results><result><binding name="foo"><literal>test</literal></binding></result></results></sparql>"#.as_slice())? {
    assert_eq!(solutions.variables(), &[Variable::new("foo")?, Variable::new("bar")?]);
    for solution in solutions {
        assert_eq!(solution?.iter().collect::<Vec<_>>(), vec![(&Variable::new("foo")?, &Literal::from("test").into())]);
    }
}

Source

pub fn read_results<R: Read>( &self, reader: R, ) -> Result<ReaderQueryResultsParserOutput<R>, QueryResultsParseError>

👎Deprecated since 0.4.0: use for_read

Source

pub fn for_slice( self, slice: &[u8], ) -> Result<SliceQueryResultsParserOutput<'_>, QueryResultsSyntaxError>

Reads a result file from a Read implementation.

Reads are automatically buffered.

Example in XML (the API is the same for JSON and TSV):

use sparesults::{QueryResultsFormat, QueryResultsParser, SliceQueryResultsParserOutput};
use oxrdf::{Literal, Variable};

let xml_parser = QueryResultsParser::from_format(QueryResultsFormat::Xml);

// boolean
if let SliceQueryResultsParserOutput::Boolean(v) = xml_parser.clone().for_slice(br#"<sparql xmlns="http://www.w3.org/2005/sparql-results#"><head/><boolean>true</boolean></sparql>"#)? {
    assert_eq!(v, true);
}

// solutions
if let SliceQueryResultsParserOutput::Solutions(solutions) = xml_parser.for_slice(br#"<sparql xmlns="http://www.w3.org/2005/sparql-results#"><head><variable name="foo"/><variable name="bar"/></head><results><result><binding name="foo"><literal>test</literal></binding></result></results></sparql>"#)? {
    assert_eq!(solutions.variables(), &[Variable::new("foo")?, Variable::new("bar")?]);
    for solution in solutions {
        assert_eq!(solution?.iter().collect::<Vec<_>>(), vec![(&Variable::new("foo")?, &Literal::from("test").into())]);
    }
}