/**
 * q-Gram Similarity
 * src/metric/QGram.ts
 *
 * @see https://en.wikipedia.org/wiki/Q-gram
 *
 * Q-gram similarity is a string-matching algorithm that compares two strings by
 * breaking them into substrings (q-grams) of length Q. The similarity is computed
 * as the size of the intersection of q-gram sets divided by the size of the larger
 * set.
 *
 * This metric is widely used in approximate string matching, information retrieval,
 * and computational linguistics.
 *
 * @module Metric
 * @name QGramSimilarity
 * @author Paul Köhler (komed3)
 * @license MIT
 */
import type { MetricCompute, MetricInput, MetricOptions } from '../utils/Types';
import { Metric } from './Metric';
export interface QGramRaw {
    intersection: number;
    size: number;
}
/**
 * QGramSimilarity class extends the Metric class to implement the q-Gram similarity algorithm.
 */
export declare class QGramSimilarity extends Metric<QGramRaw> {
    /**
     * Constructor for the QGramSimilarity class.
     *
     * Initializes the q-Gram similarity metric with two input strings or
     * arrays of strings and optional options.
     *
     * Metric is symmetrical.
     *
     * @param {MetricInput} a - First input string or array of strings
     * @param {MetricInput} b - Second input string or array of strings
     * @param {MetricOptions} [opt] - Options for the metric computation
     */
    constructor(a: MetricInput, b: MetricInput, opt?: MetricOptions);
    /**
     * Converts a string into a set of q-grams (substrings of length q).
     *
     * @param {string} str - The input string
     * @param {number} q - The length of each q-gram
     * @return {Set< string >} - Set of q-grams
     */
    private _qGrams;
    /**
     * Calculates the q-Gram similarity between two strings.
     *
     * @param {string} a - First string
     * @param {string} b - Second string
     * @return {MetricCompute< QGramRaw >} - Object containing the similarity result and raw values
     */
    protected compute(a: string, b: string): MetricCompute<QGramRaw>;
}