'use strict';
exports.__esModule = true;
exports['default'] = concatMap;
var _mergeMapSupport = require('./mergeMap-support');
/**
* Maps values from the source observable into new Observables, then merges them in a serialized fashion,
* waiting for each one to complete before merging the next.
*
* __Warning:__ if incoming values arrive endlessly and faster than the observables they're being mapped
* to can complete, it will result in memory issues as created observables amass in an unbounded buffer
* waiting for their turn to be subscribed to.
*
* @param {function} project a function to map incoming values into Observables to be concatenated. accepts
* the `value` and the `index` as arguments.
* @param {function} [projectResult] an optional result selector that is applied to values before they're
* merged into the returned observable. The arguments passed to this function are:
* - `outerValue`: the value that came from the source
* - `innerValue`: the value that came from the projected Observable
* - `outerIndex`: the "index" of the value that came from the source
* - `innerIndex`: the "index" of the value from the projected Observable
* @returns {Observable} an observable of values merged from the projected Observables as they were subscribed to,
* one at a time. Optionally, these values may have been projected from a passed `projectResult` argument.
*/
function concatMap(project, projectResult) {
return this.lift(new _mergeMapSupport.MergeMapOperator(project, projectResult, 1));
}
module.exports = exports['default']; |