import { Accum } from "../_interfaces";
import { Observable } from "../Observable";
import { Property } from "../Property";
/**
 * Scans `EventStream` or `Property` with given seed value and accumulator
 * function, resulting to a `Property`. The seed value is used as an initial
 * value for the result property.
 *
 * @param seed Seed value to use for the accumulation
 * @param acc Accumulator function `(state, value) => state`
 * @param observable Source observable
 *
 * @example
 *
 * F.pipe(F.fromArray(["!", "!"]),
 *  F.scan("Hello Francis", (state, value) => state + value),
 *  F.log("Greeting:"))
 * // logs: "Hello Francis", "Hello Francis!", "Hello Francis!!", <end>
 *
 * @stateful
 * @public
 */
export declare const scan: CurriedScan;
export interface CurriedScan {
    <StateType, ValueType>(seed: StateType, acc: Accum<StateType, ValueType>, observable: Observable<ValueType>): Property<StateType>;
    <StateType>(seed: StateType): <ValueType>(acc: Accum<StateType, ValueType>, observable: Observable<ValueType>) => Property<StateType>;
    <StateType, ValueType>(seed: StateType, acc: Accum<StateType, ValueType>): (observable: Observable<ValueType>) => Property<StateType>;
    <StateType>(seed: StateType): <ValueType>(acc: Accum<StateType, ValueType>) => (observable: Observable<ValueType>) => Property<StateType>;
}