koncorde/lib/transform/canonical.d.ts

Supersonic reverse matching engine

import { JSONObject } from '../types/JSONObject';
/**
 * Converts filters in canonical form
 *
 * @constructor
 * @param {Object} config
 */
export declare class Canonical {
    config: JSONObject;
    constructor(config: any);
    /**
     * Entry point of the normalizer: takes a filter in, and reduces it
     * into a simplified version
     *
     * Result format:
     *  [
     *    [{condition: {...}, not: <boolean>}, {condition: {...}, not: <boolean>}, ...],
     *    [{condition: {...}, not: <boolean>}, {condition: {...}, not: <boolean>}, ...],
     *    ...
     *  ]
     *
     * Explanation:
     *  Each array entry contains an array of conditions. Each one of these conditions are linked
     *  using a AND operand.
     *  Array entries are linked together with OR operands.
     *
     * @param filters
     * @return {Array} resolving to a simplified filters array
     * @throws if espresso is unable to normalize the provided filters
     */
    convert(filters: JSONObject): JSONObject[][];
    /**
     * Transforms an array of conditions into the format expected by the store
     * @param {Object[]} conds
     * @private
     */
    _andOr(conds: JSONObject[]): JSONObject[];
    /**
     * Custom _.cloneDeep equivalent, which keeps the _isLeaf non-enumerable
     * property of the filters
     * @param {Array|Object} filters
     * @returns {Array|Object}
     * @private
     */
    _cloneFilters(filters: any): JSONObject[] | JSONObject;
    /**
     * Extracts the conditions from a filter set
     *
     * @param {Object} filters
     * @param {Array} [conditions]
     * @return {Array}
     */
    _extractConditions(filters: JSONObject, conditions?: JSONObject[]): JSONObject[];
    /**
     * Returns the number of conditions as reworked by _extractConditions
     *
     * @param {Array} conditions
     * @return {Number
     */
    _countConditions(conditions: JSONObject[]): number;
    /**
     * Given some standardized filters, returns the DNF form in espresso format
     * @param filters
     * @param conditions
     * @returns {String[]}
     * @private
     */
    _normalize(filters: JSONObject, conditions: JSONObject[]): string[];
    /**
     * Negates an array of filters in the format expected by the storage
     * @param conds
     * @private
     */
    _notAndOr(conds: JSONObject[]): JSONObject[];
    _removeImpossiblePredicates(ors: JSONObject[][]): JSONObject[][];
}