import type * as RDF from '@rdfjs/types';
import type { IItemScope } from './IItemScope';
import type { IVocabRegistry } from './IVocabRegistry';
/**
 * A collection of utility functions.
 */
export declare class Util {
    static readonly RDF = "http://www.w3.org/1999/02/22-rdf-syntax-ns#";
    static readonly XSD = "http://www.w3.org/2001/XMLSchema#";
    static readonly RDFA = "http://www.w3.org/ns/rdfa#";
    private static readonly IRI_REGEX;
    readonly dataFactory: RDF.DataFactory;
    baseIRI: string;
    constructor(dataFactory?: RDF.DataFactory, baseIRI?: string);
    /**
     * Check if the given IRI is valid.
     * @param {string} iri A potential IRI.
     * @return {boolean} If the given IRI is valid.
     */
    static isValidIri(iri: string): boolean;
    /**
     * Create vocab terms for the given terms attribute.
     *
     * Relative IRIs will be based on the active vocab or baseIRI if `allowRelativeIris` is true.
     *
     * @param {string} terms An attribute value.
     * @param {IItemScope} itemScope The active item scope.
     * @param {boolean} allowRelativeIris If relative IRIs are allowed.
     * @return {Term[]} The IRI terms.
     */
    createVocabIris(terms: string, itemScope: IItemScope, allowRelativeIris: boolean): RDF.NamedNode[];
    /**
     * Get the predicates for which the given itemprop value should cause vocabulary expansion.
     * @param terms An attribute value.
     * @param itemScope The active item scope.
     * @param vocabRegistry The active vocabulary registry.
     */
    getVocabularyExpansionType(terms: string, itemScope: IItemScope, vocabRegistry: IVocabRegistry): RDF.NamedNode[];
    /**
     * Create a named node for the given term, which can be relative to the document base.
     * @param {string} iri A term string.
     * @return {Term} An RDF term, or undefined if invalid.
     */
    createSubject(iri: string): RDF.NamedNode | undefined;
    /**
     * Create a new literal node.
     * @param {string} literal The literal value.
     * @param {IActiveTag} activeTag The current active tag.
     * @return {Literal} A new literal node.
     */
    createLiteral(literal: string, activeTag: IItemScope): RDF.Literal;
    /**
     * Determine the vocab IRI from a given type IRI.
     * @link https://w3c.github.io/microdata-rdf/#property-uri-generation
     * @param typeIri A type IRI.
     * @param vocabRegistry The active vocabulary registry.
     */
    deriveVocab(typeIri: string, vocabRegistry: IVocabRegistry): string;
}