Trait Graph

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pub trait Graph {
    type Triple<'x>: Triple
       where Self: 'x;
    type Error: Error + Send + Sync + 'static;

Show 14 methods    // Required method
    fn triples(
        &self,
    ) -> impl Iterator<Item = GResult<Self, Self::Triple<'_>>> + '_;

    // Provided methods
    fn triples_matching<'s, S, P, O>(
        &'s self,
        sm: S,
        pm: P,
        om: O,
    ) -> impl Iterator<Item = GResult<Self, Self::Triple<'s>>> + 's
       where S: TermMatcher + 's,
             P: TermMatcher + 's,
             O: TermMatcher + 's { ... }
    fn contains<TS, TP, TO>(&self, s: TS, p: TP, o: TO) -> GResult<Self, bool>
       where TS: Term,
             TP: Term,
             TO: Term { ... }
    fn subjects(
        &self,
    ) -> impl Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_ { ... }
    fn predicates(
        &self,
    ) -> impl Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_ { ... }
    fn objects(
        &self,
    ) -> impl Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_ { ... }
    fn iris(&self) -> impl Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_ { ... }
    fn blank_nodes(
        &self,
    ) -> impl Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_ { ... }
    fn literals(
        &self,
    ) -> impl Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_ { ... }
    fn quoted_triples<'s>(
        &'s self,
    ) -> Box<dyn Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_>
       where GTerm<'s, Self>: Clone { ... }
    fn variables(
        &self,
    ) -> impl Iterator<Item = GResult<Self, GTerm<'_, Self>>> + '_ { ... }
    fn as_dataset(&self) -> GraphAsDataset<&Self> { ... }
    fn as_dataset_mut(&mut self) -> GraphAsDataset<&mut Self> { ... }
    fn into_dataset(self) -> GraphAsDataset<Self>
       where Self: Sized { ... }
}

Expand description

Generic trait for RDF graphs.

For convenience, this trait is implemented by standard collections of triples.

NB: the semantics of this trait allows a graph to contain duplicate triples; see also SetGraph.

Required Associated Types§

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type Triple<'x>: Triple where Self: 'x

Determine the type of Triples that the methods of this graph will yield.

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type Error: Error + Send + Sync + 'static

The error type that this graph may raise.

Required Methods§

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fn triples(&self) -> impl Iterator<Item = GResult<Self, Self::Triple<'_>>> + '_

An iterator visiting all triples of this graph in arbitrary order.

This iterator is fallible: its items are Results, an error may occur at any time during the iteration.

§Examples

The result of this method is an iterator, so it can be used in a for loop:

for t in graph.triples() {
    let t = t?; // rethrow error if any
    // do something with t
}

Another way is to use the specific methods provided by TripleSource, for example:

graph.triples().for_each_triple(|t| {
    // do something with t
})?; // rethrow error if any

Provided Methods§

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fn triples_matching<'s, S, P, O>( &'s self, sm: S, pm: P, om: O, ) -> impl Iterator<Item = GResult<Self, Self::Triple<'s>>> + 's
where S: TermMatcher + 's, P: TermMatcher + 's, O: TermMatcher + 's,

An iterator visiting all triples matching the given subject, predicate and object. See crate::term::matcher.

§Usage

Typical implementations of TermMatcher include arrays/slices of Terms, closure accepting a SimpleTerm, or the special matcher Any.

let s = Namespace::new("http://schema.org/")?;
let city = s.get("City")?;
let country = s.get("Country")?;

for t in graph.triples_matching(Any, [&rdf::type_], [city, country]) {
    println!("{:?} was found", t?.s());
}

Here is another example using a closure as a TermMatcher.

for t in graph.triples_matching(
    Any,
    [&rdfs::label],
    |t: SimpleTerm| t.lexical_form().map(|v| v.contains("needle")).unwrap_or(false),
) {
    println!("{:?} was found", t?.s());
}

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fn contains<TS, TP, TO>(&self, s: TS, p: TP, o: TO) -> GResult<Self, bool>
where TS: Term, TP: Term, TO: Term,

Return true if this graph contains the given triple.

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