/**
 * Transformers change and combine streams, similar to operators.
 * urx comes with two combinators - [[combineLatest]] and [[merge]], and one convenience filter - [[duc]].
 *
 * @packageDocumentation
 */
import { Emitter } from './actions';
import { Comparator } from './pipe';
/**
 * Merges one or more emitters from the same type into a new Emitter which emits values from any of the source emitters.
 * ```ts
 * const foo = stream<number>()
 * const bar = stream<number>()
 *
 * subscribe(merge(foo, bar), (value) => console.log(value)) // 42, 43
 *
 * publish(foo, 42)
 * publish(bar, 43)
 * ```
 */
export declare function merge<T>(...sources: Emitter<T>[]): Emitter<T>;
/**
 * A convenience wrapper that emits only the distinct values from the passed Emitter. Wraps [[pipe]] and [[distinctUntilChanged]].
 *
 * ```ts
 * const foo = stream<number>()
 *
 * // this line...
 * const a = duc(foo)
 *
 * // is equivalent to this
 * const b = pipe(distinctUntilChanged(foo))
 * ```
 *
 * @param source The source emitter.
 * @param comparator optional custom comparison function for the two values.
 *
 * @typeParam T the type of the value emitted by the source.
 *
 * @returns the resulting emitter.
 */
export declare function duc<T>(source: Emitter<T>, comparator?: Comparator<T>): Emitter<T>;
/**
 * Creates an emitter with the latest values from all passed emitters as an array.
 *
 * `combineLatest` acts as a Depot. Using it on stateless streams persists the last emitted value of each [[Emitter]].
 * Provided that all emitters have emitted at least once, subscribing to the resulting emitter will immediately receive their combined latest values.
 *
 * ```ts
 * const foo = stream<number>()
 * const bar = stream<number>()
 *
 * subscribe(combineLatest(foo, bar), ([foo, bar]) => console.log({ foo, bar }))
 *
 * publish(foo, 42)
 * publish(bar, 43) // { foo: 42, bar: 43 }
 * publish(foo, 44) // { foo: 44, bar: 43 }
 * publish(bar, 45) // { foo: 44, bar: 45 }
 * ```
 */
export declare function combineLatest<O1, O2>(...emitters: [Emitter<O1>, Emitter<O2>]): Emitter<[O1, O2]>;
export declare function combineLatest<O1, O2, O3>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>]): Emitter<[O1, O2, O3]>;
export declare function combineLatest<O1, O2, O3, O4>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>]): Emitter<[O1, O2, O3, O4]>;
export declare function combineLatest<O1, O2, O3>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>]): Emitter<[O1, O2, O3]>;
export declare function combineLatest<O1, O2, O3, O4, O5>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>, Emitter<O5>]): Emitter<[O1, O2, O3, O4, O5]>;
export declare function combineLatest<O1, O2, O3, O4, O5, O6>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>, Emitter<O5>, Emitter<O6>]): Emitter<[O1, O2, O3, O4, O5, O6]>;
export declare function combineLatest<O1, O2, O3, O4, O5, O6, O7>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>, Emitter<O5>, Emitter<O6>, Emitter<O7>]): Emitter<[O1, O2, O3, O4, O5, O6, O7]>;
export declare function combineLatest<O1, O2, O3, O4, O5, O6, O7, O8>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>, Emitter<O5>, Emitter<O6>, Emitter<O7>, Emitter<O8>]): Emitter<[O1, O2, O3, O4, O5, O6, O7, O8]>;
export declare function combineLatest<O1, O2, O3, O4, O5, O6, O7, O8, O9>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>, Emitter<O5>, Emitter<O6>, Emitter<O7>, Emitter<O8>, Emitter<O9>]): Emitter<[O1, O2, O3, O4, O5, O6, O7, O8, O9]>;
export declare function combineLatest<O1, O2, O3, O4, O5, O6, O7, O8, O9, O10>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>, Emitter<O5>, Emitter<O6>, Emitter<O7>, Emitter<O8>, Emitter<O9>, Emitter<O10>]): Emitter<[O1, O2, O3, O4, O5, O6, O7, O8, O9, O10]>;
export declare function combineLatest<O1, O2, O3, O4, O5, O6, O7, O8, O9, O10, O11>(...emitters: [Emitter<O1>, Emitter<O2>, Emitter<O3>, Emitter<O4>, Emitter<O5>, Emitter<O6>, Emitter<O7>, Emitter<O8>, Emitter<O9>, Emitter<O10>, Emitter<O11>]): Emitter<[O1, O2, O3, O4, O5, O6, O7, O8, O9, O10, O11]>;