@vectara/vectara-ui/lib/utils/citations/applyCitationOrder.js

Vectara's design system, codified as a React and Sass component library

export const applyCitationOrder = (searchResults, unorderedSummary) => {
    const orderedSearchResults = [];
    const citations = unorderedSummary.match(/\[\d+\]/g) || [];
    const addedCitations = new Set();
    for (let i = 0; i < citations.length; i++) {
        const citation = citations[i];
        // Ignore citations that have already been added.
        if (addedCitations.has(citation))
            continue;
        // Extract index from [INDEX] format.
        const citationIndex = Number(citation.slice(1, citation.length - 1)) - 1;
        // Ignore citations that are out of range of the search results.
        if (citationIndex < 0 || citationIndex >= searchResults.length)
            continue;
        orderedSearchResults.push(searchResults[citationIndex]);
        addedCitations.add(citation);
    }
    return orderedSearchResults;
};