/**
 * Deep Merge Utility
 * src/utils/DeepMerge.ts
 *
 * This module provides the utility class `DeepMerge` for deep merging objects and
 * manipulating nested properties using path strings. It allows you to get, set,
 * check, and delete values at deeply nested paths within an object, as well as
 * merge two objects together while preserving their structure.
 *
 * It supports dot and bracket notation (e.g. `a.b[0].c`) as well as escaped keys.
 *
 * @module Utils
 * @name DeepMerge
 * @author Paul Köhler
 * @license MIT
 */
/**
 * DeepMerge class provides static methods for deep merging objects and
 * manipulating nested properties using path strings.
 */
export declare class DeepMerge {
    /** Regular expression to match bracket notation in paths */
    private static readonly BRACKET_PATTERN;
    /** Path cache for efficient parsing */
    private static readonly PATH_CACHE;
    /**
     * Walk through an object using an array of keys and return
     * whether the path exists and its value.
     *
     * @param {any} obj - The object to walk through
     * @param {( string | number )[]} keys - An array of keys representing the path to walk
     * @returns {{ exists: false } | { exists: true, value: any }} -
     *      An object indicating whether the path exists and its value if it does
     */
    private static walk;
    /**
     * Parse a path string into an array of keys.
     *
     * @param {string} p - The path string, e.g. `a.b.c` or `a[0].b`
     * @returns {( string | number )[]} - An array of keys, e.g. `['a', 'b', 'c']` or `['a', 0, 'b']`
     */
    static parse(p: string): (string | number)[];
    /**
     * Check if a path exists in an object.
     *
     * @template T - The type of the object to get the value from
     * @param {T} t - The object to check
     * @param {string} path - The path string, e.g. `a.b.c`
     * @returns {boolean} - True if the path exists, otherwise false
     */
    static has<T extends Record<string, any>>(t: T, path: string): boolean;
    /**
     * Deeply get a value from an object by a path string.
     *
     * @template T - The type of the object to get the value from
     * @template R - The return type of the value
     * @param {T} t - The object to get the value from
     * @param {string} path - The path string, e.g. `a.b.c`
     * @param {any} fb - The default value to return if the path does not exist
     * @returns {R | undefined} - The value at the specified path, otherwise the default value
     */
    static get<T extends Record<string, any>, R = any>(t: T, path: string, fb?: R): R | undefined;
    /**
     * Deeply set a value in an object by a path string.
     *
     * @template T - The type of the object to get the value from
     * @param {T} t - The object to set the value in
     * @param {string} path - The path string, e.g. `a.b.c`
     * @param {any} value - The value to set at the specified path
     * @returns {T} - The modified object with the value set at the specified path
     * @throws {CmpStrUsageError} - If the path is invalid or if a non-object value is encountered along the path
     */
    static set<T extends Record<string, any>>(t: T, path: string, value: any): T;
    /**
     * Delete a value at a specified path in an object.
     *
     * @template T - The type of the object to get the value from
     * @param {T} t - The object to delete the value from
     * @param {string} path - The path string, e.g. `a.b.c`
     * @param {boolean} [preserveEmpty=false] - Whether to preserve empty objects/arrays
     * @returns {T} - The modified object with the value deleted at the specified path
     */
    static rmv<T extends Record<string, any>>(t: T, path: string, preserveEmpty?: boolean): T;
    /**
     * Deeply merge two objects, where the second object overrides the first.
     *
     * @template T - The type of the object to get the value from
     * @param {T} t - The target object to merge into
     * @param {T} o - The source object to merge from
     * @param {boolean} [mergeUndefined=false] - Whether to merge undefined values
     * @returns {T} - The merged object
     */
    static merge<T extends Record<string, any>>(t?: T | undefined, o?: T | undefined, mergeUndefined?: boolean): T;
}