import type { EntryCallback, ReduceEntryCallback } from '../../types';
/**
 * Iterable view over key-value entries.
 * @template K - Key type.
 * @template V - Value type.
 * @remarks Time O(1), Space O(1)
 */
export declare abstract class IterableEntryBase<K = any, V = any> {
    /**
     * Total number of entries.
     * @returns Entry count.
     * @remarks Time O(1), Space O(1)
     */
    abstract get size(): number;
    /**
     * Default iterator yielding `[key, value]` entries.
     * @returns Iterator of `[K, V]`.
     * @remarks Time O(n) to iterate, Space O(1)
     */
    [Symbol.iterator](...args: unknown[]): IterableIterator<[K, V]>;
    /**
     * Iterate over `[key, value]` pairs (may yield `undefined` values).
     * @returns Iterator of `[K, V | undefined]`.
     * @remarks Time O(n), Space O(1)
     */
    entries(): IterableIterator<[K, V | undefined]>;
    /**
     * Iterate over keys only.
     * @returns Iterator of keys.
     * @remarks Time O(n), Space O(1)
     */
    keys(): IterableIterator<K>;
    /**
     * Iterate over values only.
     * @returns Iterator of values.
     * @remarks Time O(n), Space O(1)
     */
    values(): IterableIterator<V>;
    /**
     * Test whether all entries satisfy the predicate.
     * @param predicate - `(key, value, index, self) => boolean`.
     * @param thisArg - Optional `this` for callback.
     * @returns `true` if all pass; otherwise `false`.
     * @remarks Time O(n), Space O(1)
     */
    every(predicate: EntryCallback<K, V, boolean>, thisArg?: unknown): boolean;
    /**
     * Test whether any entry satisfies the predicate.
     * @param predicate - `(key, value, index, self) => boolean`.
     * @param thisArg - Optional `this` for callback.
     * @returns `true` if any passes; otherwise `false`.
     * @remarks Time O(n), Space O(1)
     */
    some(predicate: EntryCallback<K, V, boolean>, thisArg?: unknown): boolean;
    /**
     * Visit each entry, left-to-right.
     * @param callbackfn - `(key, value, index, self) => void`.
     * @param thisArg - Optional `this` for callback.
     * @remarks Time O(n), Space O(1)
     */
    forEach(callbackfn: EntryCallback<K, V, void>, thisArg?: unknown): void;
    /**
     * Find the first entry that matches a predicate.
     * @param callbackfn - `(key, value, index, self) => boolean`.
     * @param thisArg - Optional `this` for callback.
     * @returns Matching `[key, value]` or `undefined`.
     * @remarks Time O(n), Space O(1)
     */
    find(callbackfn: EntryCallback<K, V, boolean>, thisArg?: unknown): [K, V] | undefined;
    /**
     * Whether the given key exists.
     * @param key - Key to test.
     * @returns `true` if found; otherwise `false`.
     * @remarks Time O(n) generic, Space O(1)
     */
    has(key: K): boolean;
    /**
     * Whether there exists an entry with the given value.
     * @param value - Value to test.
     * @returns `true` if found; otherwise `false`.
     * @remarks Time O(n), Space O(1)
     */
    hasValue(value: V): boolean;
    /**
     * Get the value under a key.
     * @param key - Key to look up.
     * @returns Value or `undefined`.
     * @remarks Time O(n) generic, Space O(1)
     */
    get(key: K): V | undefined;
    /**
     * Reduce entries into a single accumulator.
     * @param callbackfn - `(acc, value, key, index, self) => acc`.
     * @param initialValue - Initial accumulator.
     * @returns Final accumulator.
     * @remarks Time O(n), Space O(1)
     */
    reduce<U>(callbackfn: ReduceEntryCallback<K, V, U>, initialValue: U): U;
    /**
     * Converts data structure to `[key, value]` pairs.
     * @returns Array of entries.
     * @remarks Time O(n), Space O(n)
     */
    toArray(): [K, V][];
    /**
     * Visualize the iterable as an array of `[key, value]` pairs (or a custom string).
     * @returns Array of entries (default) or a string.
     * @remarks Time O(n), Space O(n)
     */
    toVisual(): [K, V][] | string;
    /**
     * Print a human-friendly representation to the console.
     * @remarks Time O(n), Space O(n)
     */
    print(): void;
    /**
     * Whether there are no entries.
     * @returns `true` if empty; `false` otherwise.
     * @remarks Time O(1) typical, Space O(1)
     */
    abstract isEmpty(): boolean;
    /**
     * Remove all entries.
     * @remarks Time O(n) typical, Space O(1)
     */
    abstract clear(): void;
    /**
     * Deep clone preserving the concrete subtype.
     * @returns A new instance of the same concrete class (`this` type).
     * @remarks Time O(n) typical, Space O(n)
     */
    abstract clone(): this;
    /**
     * Map entries using an implementation-specific strategy.
     * @remarks Time O(n), Space O(n)
     */
    abstract map(...args: unknown[]): unknown;
    /**
     * Filter entries and return the same-species structure.
     * @returns A new instance of the same concrete class (`this` type).
     * @remarks Time O(n), Space O(n)
     */
    abstract filter(...args: unknown[]): this;
    /**
     * Underlying iterator for the default iteration protocol.
     * @returns Iterator of `[K, V]`.
     * @remarks Time O(n), Space O(1)
     */
    protected abstract _getIterator(...args: unknown[]): IterableIterator<[K, V]>;
}