Trait Dataset

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pub trait Dataset {
    type Quad<'x>: Quad
       where Self: 'x;
    type Error: Error + 'static;

Show 17 methods    // Required method
    fn quads(&self) -> DQuadSource<'_, Self>;

    // Provided methods
    fn quads_matching<'s, S, P, O, G>(
        &'s self,
        sm: S,
        pm: P,
        om: O,
        gm: G,
    ) -> DQuadSource<'s, Self>
       where S: TermMatcher + 's,
             P: TermMatcher + 's,
             O: TermMatcher + 's,
             G: GraphNameMatcher + 's { ... }
    fn contains<TS, TP, TO, TG>(
        &self,
        s: TS,
        p: TP,
        o: TO,
        g: GraphName<TG>,
    ) -> DResult<Self, bool>
       where TS: Term,
             TP: Term,
             TO: Term,
             TG: Term { ... }
    fn subjects(&self) -> DTermSource<'_, Self> { ... }
    fn predicates(&self) -> DTermSource<'_, Self> { ... }
    fn objects(&self) -> DTermSource<'_, Self> { ... }
    fn graph_names(&self) -> DTermSource<'_, Self> { ... }
    fn iris(&self) -> DTermSource<'_, Self> { ... }
    fn blank_nodes(&self) -> DTermSource<'_, Self> { ... }
    fn literals(&self) -> DTermSource<'_, Self> { ... }
    fn quoted_triples<'s>(&'s self) -> DTermSource<'s, Self>
       where DTerm<'s, Self>: Clone { ... }
    fn variables(&self) -> DTermSource<'_, Self> { ... }
    fn graph<T>(&self, graph_name: GraphName<T>) -> DatasetGraph<&Self, T>
       where T: for<'x> Term<BorrowTerm<'x> = DTerm<'x, Self>> + 'static { ... }
    fn graph_mut<T>(
        &mut self,
        graph_name: GraphName<T>,
    ) -> DatasetGraph<&mut Self, T>
       where T: for<'x> Term<BorrowTerm<'x> = DTerm<'x, Self>> + 'static { ... }
    fn partial_union_graph<M>(&self, selector: M) -> PartialUnionGraph<&Self, M>
       where M: GraphNameMatcher + Copy { ... }
    fn union_graph(&self) -> UnionGraph<&Self> { ... }
    fn into_union_graph(self) -> UnionGraph<Self>
       where Self: Sized { ... }
}

Expand description

Generic trait for RDF datasets.

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

NB: the semantics of this trait allows a dataset to contain duplicate quads; see also SetDataset.

Required Associated Types§

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

Determine the type of Quads that the methods of this dataset will yield.

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type Error: Error + 'static

The error type that this dataset may raise.

Required Methods§

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fn quads(&self) -> DQuadSource<'_, Self>

An iterator visiting all quads of this dataset 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 q in dataset.quads() {
    let q = q?; // rethrow error if any
    // do something with q
}

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

dataset.quads().for_each_quad(|q| {
    // do something with q
})?; // rethrow error if any

Provided Methods§

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fn quads_matching<'s, S, P, O, G>( &'s self, sm: S, pm: P, om: O, gm: G, ) -> DQuadSource<'s, Self>
where S: TermMatcher + 's, P: TermMatcher + 's, O: TermMatcher + 's, G: GraphNameMatcher + 's,

An iterator visiting all quads 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 q in dataset.quads_matching(Any, [&rdf::type_], [city, country], Any) {
    println!("{:?} was found", q?.s());
}

Here is another example using a closure as a TermMatcher.

use sophia_api::term::matcher::Any;

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

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

Return true if this dataset contains the given quad.

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