import { Stream } from 'xstream';
import { InternalInstances, ItemKeyFn, ItemScopeFn, ItemFactoryFn } from './types';
/**
 * An object representing all instances in a collection of components. Has the
 * methods pickCombine and pickMerge to get the combined sinks of all instances.
 */
export declare class Instances<Si> {
    private _instances$;
    constructor(instances$: Stream<InternalInstances<Si>>);
    /**
     * Like `merge` in xstream, this operator blends multiple streams together, but
     * picks those streams from a collection of component instances.
     *
     * Use the `selector` string to pick a stream from the sinks object of each
     * component instance, then pickMerge will merge all those picked streams.
     *
     * @param {String} selector a name of a channel in a sinks object belonging to
     * each component in the collection of components.
     * @return {Function} an operator to be used with xstream's `compose` method.
     */
    pickMerge(selector: string): Stream<any>;
    /**
     * Like `combine` in xstream, this operator combines multiple streams together,
     * but picks those streams from a collection of component instances.
     *
     * Use the `selector` string to pick a stream from the sinks object of each
     * component instance, then pickCombine will combine all those picked streams.
     *
     * @param {String} selector a name of a channel in a sinks object belonging to
     * each component in the collection of components.
     * @return {Function} an operator to be used with xstream's `compose` method.
     */
    pickCombine(selector: string): Stream<Array<any>>;
}
interface BaseOptions<S, So, Si> {
    /**
     * A function that describes how to collect all the sinks from all item
     * instances. The instances argument is an object with two methods: pickMerge
     * and pickCombine. These behave like xstream "merge" and "combine" operators,
     * but are applied to the dynamic collection of all item instances.
     *
     * This function should return an object of sinks. This is what the collection
     * component will output as its sinks.
     */
    collectSinks(instances: Instances<Si>): any;
    /**
     * Specify, from the state object for each item in the collection, a key for
     * that item. This avoids bugs when the collection grows or shrinks, as well
     * as helps determine the isolation scope for each item, when specifying the
     * `itemScope` option. This function also takes the index number (from the
     * corresponding entry in the state array) as the second argument.
     *
     * Example:
     *
     * ```js
     * itemKey: (itemState, index) => itemState.key
     * ```
     */
    itemKey?: ItemKeyFn<S>;
    /**
     * Specify each item's isolation scope, given the item's key.
     *
     * Pass a function which describes how to create the isolation scopes for each
     * item component, given that item component's unique key. The unique key for
     * each item was defined by the `itemKey` option.
     */
    itemScope?: ItemScopeFn;
    /**
     * Choose the channel name where the StateSource exists. Typically this is
     * 'state', but you can customize it if your app is using another name. It is
     * used for referencing the correct source used for describing
     * growing/shrinking of the collection of items.
     */
    channel?: string;
}
interface HomogenousOptions<S, So, Si> extends BaseOptions<S, So, Si> {
    /**
     * The Cycle.js component for each item in this collection. Should be just a
     * function from sources to sinks.
     */
    item(so: So): Si;
    itemFactory?: never;
}
interface HeterogenousOptions<S, So, Si> extends BaseOptions<S, So, Si> {
    item?: never;
    /**
     * A factory function such that given the item's state object, returns
     * the Cycle.js component for that item in this collection.
     */
    itemFactory: ItemFactoryFn<S, So, Si>;
}
export declare type CollectionOptions<S, So, Si> = HomogenousOptions<S, So, Si> | HeterogenousOptions<S, So, Si>;
export declare function makeCollection<S, So = any, Si = any>(opts: CollectionOptions<S, So, Si>): (sources: any) => any;
export {};