import { Maybe } from 'monet';
/**
 * Gets the value of the map at the specified key.
 * @param key - the key to get
 * @returns a Some of the value if it exists, a None otherwise
 * ```typescript
 * pipe(
 *   new Map([
 *     ['a', 1],
 *     ['b', 2]
 *   ]),
 *   Maps.get('b') // -> Some(2)
 * );
 *
 * pipe(
 *   new Map([
 *     ['a', 1],
 *     ['b', 2]
 *   ]),
 *   Maps.get('c') // -> None
 * );
 * ```
 */
export declare function get<K, V>(key: K): (map: Map<K, V>) => Maybe<V>;
/**
 * Gets the size of the map.
 * @returns the size of the map
 * ```typescript
 * pipe(
 *   new Map([
 *     ['a', 1],
 *     ['b', 2]
 *   ]),
 *   Maps.size() // -> 2
 * );
 * ```
 */
export declare const size: <K, V>(noArg?: undefined) => (map: Map<K, V>) => number;
/**
 * Gets the keys of the map.
 * @returns the an array of the keys of the map
 * ```typescript
 * pipe(
 *   new Map([
 *     ['a', 1],
 *     ['b', 2]
 *   ]),
 *   Maps.keys() // -> ['a','b']
 * );
 * ```
 */
export declare function keys<K, V>(noArg?: never): (map: Map<K, V>) => K[];
/**
 * Gets the values of the map.
 * @returns the an array of the values of the map
 * ```typescript
 * pipe(
 *   new Map([
 *     ['a', 1],
 *     ['b', 2]
 *   ]),
 *   Maps.values() // -> [1,2]
 * );
 * ```
 */
export declare function values<K, V>(noArg?: never): (map: Map<K, V>) => V[];
/**
 * Gets the entries of the map.
 * @returns the an array of the entries of the map
 * ```typescript
 * pipe(
 *   new Map([
 *     ['a', 1],
 *     ['b', 2]
 *   ]),
 *   Maps.entries() // -> [['a',1],['b',2]]
 * );
 * ```
 */
export declare function entries<K, V>(noArg?: never): (map: Map<K, V>) => [K, V][];
/**
 * Checks whether the map contains a given key.
 * @returns true if the map contains the key
 * ```typescript
 * pipe(
 *   new Map([ [ 'a', 1 ] ]),
 *   Maps.has('b') // -> false
 * );
 * ```
 */
export declare const has: <K, V>(key: K) => (map: Map<K, V>) => boolean;
/**
 * Executes a function for each key/value pair in a map.
 * @param fn - the function to execute for each pair
 * ```typescript
 * pipe(
 *   new Map([
 *     ['a', 1],
 *     ['b', 2]
 *   ]),
 *   Maps.forEach((val, key) => console.log(key + val)) // logs: a1, b2
 * );
 * ```
 */
export declare const forEach: <K, V>(fn: (val: V, key: K, map: Map<K, V>) => void) => (set: Map<K, V>) => void;