RDF Terms

This package contains utility functions for handling RDFJS terms of quads/triples.

Usage

The following examples assume the following imports:

import { DataFactory } from "rdf-data-factory";
import * as RdfTerms from "rdf-terms";

const factory = new DataFactory();

Constants

// Prints [ 'subject', 'predicate', 'object', 'graph' ]
console.log(RdfTerms.QUAD_TERM_NAMES);

// Prints [ 'subject', 'predicate', 'object' ]
console.log(RdfTerms.TRIPLE_TERM_NAMES);

// Prints [ 'NamedNode', 'BlankNode', 'Literal', 'Variable', 'DefaultGraph', 'Quad' ]
console.log(RdfTerms.TERM_TYPES);

Get quad terms

Get all terms from a quad.

A second optional parameter can be set to true to ignore graph terms in the default graph.

// Outputs: [ namedNode('http://example.org/s'), namedNode('http://example.org/p'), literal('abc'), namedNode('http://example.org/g') ]
RdfTerms.getTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
));

// Outputs: [ namedNode('http://example.org/s'), namedNode('http://example.org/p'), literal('abc'), defaultGraph() ]
RdfTerms.getTerms(factory.triple(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
));

// Outputs: [ namedNode('http://example.org/s'), namedNode('http://example.org/p'), literal('abc') ]
RdfTerms.getTerms(factory.triple(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
), true);

Get quad nested terms

Get all nested terms from a quad. This means that if a quad's term is a nested term, instead of returning that quad, all nested terms will be included, recursively.

A second optional parameter can be set to true to ignore graph terms in the default graph.

// Outputs: [ namedNode('http://example.org/s'), namedNode('http://example.org/p'), literal('abc'), namedNode('http://example.org/g') ]
RdfTerms.getTerms(factory.quad(
  factory.quad(
    namedNode('http://example.org/a'),
    namedNode('http://example.org/b'),
    namedNode('http://example.org/c'),
    namedNode('http://example.org/d'),
  ),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
));

// Outputs: [ namedNode('http://example.org/a'), namedNode('http://example.org/b'), namedNode('http://example.org/c'), namedNode('http://example.org/d'), namedNode('http://example.org/s'), namedNode('http://example.org/p'), literal('abc'), defaultGraph() ]

Get named quad terms

Get all terms from a quad labelled with the quad term name.

This is the reverse operation from collectNamedTerms.

// Outputs: [ { subject: namedNode('http://example.org/s') }, { predicate: namedNode('http://example.org/p') }, { object: literal('abc') }, { graph: namedNode('http://example.org/g') } ]
RdfTerms.getNamedTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
));

Collect named quad terms

Create a quad from a an array of named quad terms.

This is the reverse operation from getNamedTerms.

An second optional callback method can be provided to fill in missing terms

// Outputs: quad(namedNode('http://example.org/s'), namedNode('http://example.org/p'), literal('abc'), namedNode('http://example.org/g'))
RdfTerms.collectNamedTerms([
  { subject: factory.namedNode('http://example.org/s') },
  { predicate: factory.namedNode('http://example.org/p') },
  { object: factory.literal('abc') },
  { graph: factory.namedNode('http://example.org/g') },
]);

// Outputs: quad(namedNode('http://example.org/s'), namedNode('http://example.org/newNode'), literal('abc'), namedNode('http://example.org/g'))
RdfTerms.collectNamedTerms([
  { subject: factory.namedNode('http://example.org/s') },
  // Missing predicate
  { object: factory.literal('abc') },
  { graph: factory.namedNode('http://example.org/g') },
], (termName) => factory.namedNode('http://example.org/newNode'));

An third optional argument can be passed to set a custom data factory

RdfTerms.collectNamedTerms([
  { subject: factory.namedNode('http://example.org/s') },
  { predicate: factory.namedNode('http://example.org/p') },
  { object: factory.literal('abc') },
  { graph: factory.namedNode('http://example.org/g') },
], null, myDataFactory);

Iterate over quad terms

Invokes a callback for each term in the quad.

// Outputs:
// subject: http://example.org/s
// predicate: http://example.org/p
// object: abc
// graph: http://example.org/g
RdfTerms.forEachTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), (value, key) => console.log(key + ': ' + value.value));

Iterate over nested quad terms

Invokes a callback for each term in the quad, while recursing into quoted triples.

// Outputs:
// [subject]: http://example.org/s
// [predicate]: http://example.org/p
// [object, subject]: http://example.org/s1
// [object, predicate]: http://example.org/p1
// [object, object]: abc
// [graph]: http://example.org/g
RdfTerms.forEachTermsNested(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    literal('abc'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => console.log(keys + ': ' + value.value));

Filter quad terms

Returns all quad terms that return true for a given filter.

// Output: [namedNode('http://example.org/p')]
RdfTerms.filterTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), (value, key) => key === 'predicate');

Filter nested quad terms

Returns all quad terms that return true for a given filter, while recursing into quoted triples.

// Output: [namedNode('http://example.org/p'), namedNode('http://example.org/p1')]
RdfTerms.filterTermsNested(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    literal('abc'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => keys[keys.length - 1] === 'predicate');

Filter quad term names

Returns all quad term names that return true for a given filter.

// Output: ['predicate']
RdfTerms.filterQuadTermNames(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), (value, key) => value.equals(namedNode('http://example.org/p')));

Filter nested quad term names

Returns all quad term names that return true for a given filter, while recursing into quoted triples.

// Output: [ ['predicate'], ['object', 'predicate'] ]
RdfTerms.filterQuadTermNamesNested(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    literal('abc'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => value.equals(namedNode('http://example.org/p')));

Map quad terms

Map all quad terms to form a new quad.

// Output: quad(namedNode('http://subject'), namedNode('http://predicate'), namedNode('http://object'), namedNode('http://graph'))
RdfTerms.mapTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), (value, key) => namedNode('http://' + key));

An second optional argument can be passed to set a custom data factory

// Output: quad(namedNode('http://subject'), namedNode('http://predicate'), namedNode('http://object'), namedNode('http://graph'))
RdfTerms.mapTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
),
  (value, key) => namedNode('http://' + key),
  myDataFactory);

Map nested quad terms

Map all quad terms to form a new quad, while recursing into quoted triples.

// Output: quad(
//   namedNode('http://subject'),
//   namedNode('http://predicate'),
//   quad(namedNode('http://object-subject'), namedNode('http://object-predicate'), namedNode('http://object-object'), namedNode('http://object-graph')),
//   namedNode('http://graph'),
// )
RdfTerms.mapTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    literal('abc'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => namedNode('http://' + keys.join('-')));

Reduce quad terms

Reduce the quad terms to a single value.

// Output: "START: http://example.org/s, http://example.org/p, abc, http://example.org/g"
RdfTerms.reduceTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), (previous, value, key) => previous + ', ' + value.value, 'START: ');

Reduce nested quad terms

Reduce the quad terms to a single value, while recursing into quoted triples.

// Output: "START: http://example.org/s, http://example.org/p, http://example.org/s1, http://example.org/p1, abc, abc, http://example.org/g"
RdfTerms.reduceTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    literal('abc'),
  ),
  namedNode('http://example.org/g'),
), (previous, value, key) => previous + ', ' + value.value, 'START: ');

Every quad terms

Determines whether all terms satisfy the specified test.

// Output: false
RdfTerms.everyTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), (value, key) => value.termType === 'NamedNode');

// Output: true
RdfTerms.everyTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  namedNode('http://example.org/o'),
  namedNode('http://example.org/g'),
), (value, key) => value.termType === 'NamedNode');

Every quoted quad terms

Determines whether all terms satisfy the specified test, while recursing into quoted triples.

// Output: false
RdfTerms.everyTermsNested(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    literal('abc'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => value.termType === 'NamedNode');

// Output: true
RdfTerms.everyTermsNested(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    namedNode('http://example.org/o1'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => value.termType === 'NamedNode');

Some quad terms

Determines whether at least one term satisfies the specified test.

// Output: true
RdfTerms.someTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), (value, key) => value.termType === 'NamedNode');

// Output: true
RdfTerms.someTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  namedNode('http://example.org/o'),
  namedNode('http://example.org/g'),
), (value, key) => value.termType === 'NamedNode');

// Output: false
RdfTerms.someTerms(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  namedNode('http://example.org/o'),
  namedNode('http://example.org/g'),
), (value, key) => value.termType === 'Variable');

Some nested quad terms

Determines whether at least one term satisfies the specified test, while recursing into quoted triples.

// Output: true
RdfTerms.someTermsNested(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    literal('abc'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => value.termType === 'Literal');

// Output: false
RdfTerms.someTermsNested(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    namedNode('http://example.org/o1'),
  ),
  namedNode('http://example.org/g'),
), (value, keys) => value.termType === 'Literal');

Get value in nested path

Get the nested value inside a quoted triple by the given path of quad keys.

// Output: literal('abc')
RdfTerms.getValueNestedPath(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  factory.quad(
    namedNode('http://example.org/s1'),
    namedNode('http://example.org/p1'),
    factory.quad(
      namedNode('http://example.org/s1'),
      namedNode('http://example.org/p1'),
      literal('abc'),
    ),
  ),
  namedNode('http://example.org/g'),
), [ 'object', 'object', 'object' ]);

Match term

Determines if the given term matches with the given term.

// Output: true
RdfTerms.matchTerm(
  namedNode('http://example.org/s'),
  undefined,
);

// Output: true
RdfTerms.matchTerm(
  namedNode('http://example.org/s'),
  variable('v'),
);

// Output: true
RdfTerms.matchTerm(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/s'),
);

// Output: true
RdfTerms.matchTerm(
  factory.quad(
    namedNode('http://example.org/s'),
    namedNode('http://example.org/p'),
    literal('abc'),
    namedNode('http://example.org/g'),
  ),
  factory.quad(
    namedNode('http://example.org/s'),
    namedNode('http://example.org/p'),
    variable('o'),
    namedNode('http://example.org/g'),
  ),
);

Match pattern

Determines if the given quad matches with the given quad terms.

// Output: true
RdfTerms.matchPattern(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
),
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
);

// Output: true
RdfTerms.matchPattern(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
),
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
);

// Output: true
RdfTerms.matchPattern(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
),
  namedNode('http://example.org/s'),
  variable('someVariableP'),
  literal('abc'),
);

// Output: true
RdfTerms.matchPattern(factory.quad(
  factory.quad(
    namedNode('http://example.org/a'),
    namedNode('http://example.org/b'),
    namedNode('http://example.org/c'),
    namedNode('http://example.org/d'),
  ),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
),
  factory.quad(
    namedNode('http://example.org/a'),
    variable('someVariableP'),
    namedNode('http://example.org/c'),
    namedNode('http://example.org/d'),
  ),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
);


// Output: false
RdfTerms.matchPattern(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
),
  namedNode('http://example.org/s'),
  variable('someVariableP'),
  literal('abcdef'),
);

Match pattern complete

Determines if the given quad matches with the given quad pattern (A quad that contains zero or more variables).

// Output: true
RdfTerms.matchPatternComplete(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
));

// Output: true
RdfTerms.matchPatternComplete(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  variable('varA'),
  literal('abc'),
  variable('varB'),
));

// Output: false
RdfTerms.matchPatternComplete(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  variable('varA'),
  literal('abcdef'),
  variable('varB'),
));

Match pattern, taking into account variable mappings

Determines if the given quad matches with the given quad pattern (A quad that contains zero or more variables), by taking into account the mappings of the variables. If the same variable occurs multiple times in the pattern, then the corresponding terms in the quad must be equal.

// Output: true
RdfTerms.matchPatternMappings(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
));

// Output: true
RdfTerms.matchPatternComplete(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/X'),
  literal('abc'),
  namedNode('http://example.org/X'),
), factory.quad(
  namedNode('http://example.org/s'),
  variable('varA'),
  literal('abc'),
  variable('varA'),
));

// Output: false
RdfTerms.matchPatternComplete(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/X1'),
  literal('abc'),
  namedNode('http://example.org/X2'),
), factory.quad(
  namedNode('http://example.org/s'),
  variable('varA'),
  literal('abc'),
  variable('varA'),
));

There are also the following optional parameters

• skipVarMapping - Don't add variables in the quad to the mapping
• returnMappings - Return the mappings if it is a valid match

// Output: {}
RdfTerms.matchPatternMappings(factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), { returnMappings: true });

// Output: { s: namedNode('http://example.org/s') }
RdfTerms.matchPatternMappings(factory.quad(
  variable('s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
), { returnMappings: true });

// Output: { s: namedNode('http://example.org/s'), p: variable('o') }
RdfTerms.matchPatternMappings(factory.quad(
  variable('s'),
  namedNode('http://example.org/p'),
  variable('p'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  variable('o'),
  namedNode('http://example.org/g'),
), { returnMappings: true });

// Output: { s: namedNode('http://example.org/s') }
RdfTerms.matchPatternMappings(factory.quad(
  variable('s'),
  namedNode('http://example.org/p'),
  variable('p'),
  namedNode('http://example.org/g'),
), factory.quad(
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  variable('o'),
  namedNode('http://example.org/g'),
), { returnMappings: true, skipVarMapping: true });


const quadVariables = factory.quad(variable('s'), variable('p'), variable('o'), variable('g'));

// Output: False
RdfTerms.matchPatternMappings(
  factory.quad(quadVariables, variable('p'), variable('f'), variable('g')),
  factory.quad(quadVariables, variable('p'), variable('o'), variable('g')),
)

// Output: True
RdfTerms.matchPatternMappings(
  factory.quad(quadVariables, variable('p'), variable('f'), variable('g')),
  factory.quad(quadVariables, variable('p'), variable('o'), variable('g')),
  { skipVarMapping: true }
)

Unique terms

Create an array of unique terms from the given array.

// Output: [namedNode('http://example.org/s')]
RdfTerms.uniqTerms([
  namedNode('http://example.org/s'),
  namedNode('http://example.org/s'),
]);

Get terms of type

Find all terms of the given type in the given array.

// Output: [namedNode('http://example.org/s'), namedNode('http://example.org/p'), namedNode('http://example.org/g')]
RdfTerms.getTermsOfType([
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
], 'NamedNode');

The functions getNamedNodes, getBlankNodes, getLiterals, getVariables, getDefaultGraphs are convenience variants of this function, which do not require the term type string as parameter, and perform appropriate casting in TypeScript.

// Output: [namedNode('http://example.org/s'), namedNode('http://example.org/p'), namedNode('http://example.org/g')]
RdfTerms.getNamedNodes([
  namedNode('http://example.org/s'),
  namedNode('http://example.org/p'),
  literal('abc'),
  namedNode('http://example.org/g'),
]);

License

This software is written by Ruben Taelman.

This code is released under the MIT license.