RDF Terms


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

Usage

The following examples assume the following imports:
``javascript
import { DataFactory } from "rdf-data-factory";
import * as RdfTerms from "rdf-terms";

const factory = new DataFactory();
`

$3

`javascript
// 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);
`

$3

Get all terms from a quad.

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

`javascript
// 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);
`

$3

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._

`javascript
// 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() ]
`

$3

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

This is the reverse operation from collectNamedTerms.

`javascript
// 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'),
));
`

$3

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_

`javascript
// 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_

`javascript
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);
`

$3

Invokes a callback for each term in the quad.

`javascript
// 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));
`

$3

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

`javascript
// 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));
`

$3

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

`javascript
// 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');
`

$3

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

`javascript
// 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');
`

$3

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

`javascript
// 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')));
`

$3

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

`javascript
// 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')));
`

$3

Map all quad terms to form a new quad.

`javascript
// 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_

`javascript
// 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);
`

$3

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

`javascript
// 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('-')));
`

$3

Reduce the quad terms to a single value.

`javascript
// 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: ');
`

$3

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

`javascript
// 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: ');
`

$3

Determines whether all terms satisfy the specified test.

`javascript
// 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');
`

$3

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

`javascript
// 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');
`

$3

Determines whether at least one term satisfies the specified test.

`javascript
// 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');
`

$3

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

`javascript
// 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');
`

$3

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

`javascript
// 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' ]);
`

$3

Determines if the given term matches with the given term.

`javascript
// 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'),
),
);
`

$3

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

`javascript
// 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'),
);
`

$3

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

`javascript
// 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'),
));
`

$3

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.

`javascript
// 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

`javascript
// 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 }
)
`

$3

Create an array of unique terms from the given array.

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

$3

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

`javascript
// 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._

`javascript
// 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.