@tpluscode/sparql-builder/lib/expressions/values.js

Simple JS library to build SPARQL queries

import { sparql } from '@tpluscode/rdf-string';
import RDF from '@rdfjs/data-model';
function toSingleLine(line, value) {
    return sparql `${line} ${value}`;
}
export function VALUES(...values) {
    if (values.length === 0) {
        return '';
    }
    const variables = [...new Set(values.map(Object.keys).flat())].map(RDF.variable);
    const vectors = values.reduce((previous, current) => {
        const vector = variables.map((variable) => {
            const value = current[variable.value];
            if (value === null || typeof value === 'undefined') {
                return 'UNDEF';
            }
            if (typeof value === 'string') {
                return RDF.literal(value);
            }
            return value;
        });
        return sparql `${previous}\n(${vector.reduce(toSingleLine, sparql ``)} )`;
    }, sparql ``);
    return sparql `VALUES (${variables.reduce(toSingleLine, sparql ``)} )
{${vectors}
}`;
}