Struct rio_turtle::NTriplesParser

pub struct NTriplesParser<R: BufRead> { /* fields omitted */ }

A N-Triples and N-Triples-star streaming parser.

It implements the TriplesParser trait.

Its memory consumption is linear in the size of the longest line of the file. It does not do any allocation during parsing except buffer resizing if a line significantly longer than the previous is encountered.

Count the number of people using the TriplesParser API:

use rio_turtle::{NTriplesParser, TurtleError};
use rio_api::parser::TriplesParser;
use rio_api::model::NamedNode;

let file = b"<http://example.com/foo> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/Person> .
<http://example.com/foo> <http://schema.org/name> \"Foo\" .
<http://example.com/bar> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <http://schema.org/Person> .
<http://example.com/bar> <http://schema.org/name> \"Bar\" .";

let rdf_type = NamedNode { iri: "http://www.w3.org/1999/02/22-rdf-syntax-ns#type" };
let schema_person = NamedNode { iri: "http://schema.org/Person" };
let mut count = 0;
NTriplesParser::new(file.as_ref()).parse_all(&mut |t| {
    if t.predicate == rdf_type && t.object == schema_person.into() {
        count += 1;
    }
    Ok(()) as Result<(), TurtleError>
})?;
assert_eq!(2, count);

Implementations

impl<R: BufRead> NTriplesParser<R>

pub fn new(reader: R) -> Self

Trait Implementations

impl<B: BufRead> TripleSource for NTriplesParser<B>

type Error = <NTriplesParser<B> as TriplesParser>::Error

The type of errors produced by this source.

type Triple = ScopedRioSourceTriple

Determine the type of Triples that this triple source yields. (see streaming_mode)

fn try_for_some_triple<F, EF>(
    &mut self,
    f: &mut F
) -> StreamResult<bool, Self::Error, EF> where
    F: FnMut(StreamedTriple<'_, Self::Triple>) -> Result<(), EF>,
    EF: Error, 

Call f for at least one triple from this triple source, if any.

fn try_for_each_triple<F, E>(
    &mut self,
    f: F
) -> Result<(), StreamError<Self::Error, E>> where
    F: FnMut(StreamedTriple<'_, Self::Triple>) -> Result<(), E>,
    E: Error, 

Call f for all triples from this triple source.

fn for_some_triple<F>(&mut self, f: &mut F) -> Result<bool, Self::Error> where
    F: FnMut(StreamedTriple<'_, Self::Triple>), 

Call f for at least one triple from this triple source, if any.

fn for_each_triple<F>(&mut self, f: F) -> Result<(), Self::Error> where
    F: FnMut(StreamedTriple<'_, Self::Triple>), 

Call f for all triples from this triple source.

fn filter_triples<F>(self, filter: F) -> FilterSource<Self, F> where
    F: FnMut(&StreamedTriple<'_, Self::Triple>) -> bool, 

Creates a triple source which uses a closure to determine if a triple should be yielded.

fn filter_map_triples<F, T>(self, filter_map: F) -> FilterMapSource<Self, F> where
    F: FnMut(StreamedTriple<'_, Self::Triple>) -> Option<T>, 

Creates a triple source that both filters and maps.

fn map_triples<F, T>(self, map: F) -> MapSource<Self, F> where
    F: FnMut(StreamedTriple<'_, Self::Triple>) -> T, 

Takes a closure and creates triple source which yield the result of that closure for each triple.

fn size_hint_triples(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the triple source.

fn collect_triples<G>(
    self
) -> Result<G, StreamError<Self::Error, <G as Graph>::Error>> where
    G: CollectibleGraph, 

Collect these triples into a new graph.

fn add_to_graph<G>(
    self,
    graph: &mut G
) -> Result<usize, StreamError<Self::Error, <G as MutableGraph>::MutationError>> where
    G: MutableGraph, 

Insert all triples from this source into the given MutableGraph.

impl<R: BufRead> TriplesParser for NTriplesParser<R>

type Error = TurtleError

fn parse_step<E: From<TurtleError>>(
    &mut self,
    on_triple: &mut impl FnMut(Triple<'_>) -> Result<(), E>
) -> Result<(), E>

Parses a small chunk of the file and calls on_triple each time a new triple is read. (A “small chunk” could be a line for an N-Triples parser.)

fn is_end(&self) -> bool

Returns true if the file has been completely consumed by the parser.

fn parse_all<E>(
    &mut self,
    on_triple: &mut impl FnMut(Triple<'_>) -> Result<(), E>
) -> Result<(), E> where
    E: From<Self::Error>, 

Parses the complete file and calls on_triple each time a new triple is read.

fn into_iter<T, E, F>(
    self,
    convert_triple: F
) -> TriplesParserIterator<T, E, F, Self> where
    E: From<Self::Error>,
    F: FnMut(Triple<'_>) -> Result<T, E>, 

Converts the parser into a Result<T, E> iterator.