--- /dev/null
+/** PURE_IMPORTS_START tslib,_Subscriber PURE_IMPORTS_END */
+import * as tslib_1 from "tslib";
+import { Subscriber } from '../Subscriber';
+export function scan(accumulator, seed) {
+ var hasSeed = false;
+ if (arguments.length >= 2) {
+ hasSeed = true;
+ }
+ return function scanOperatorFunction(source) {
+ return source.lift(new ScanOperator(accumulator, seed, hasSeed));
+ };
+}
+var ScanOperator = /*@__PURE__*/ (function () {
+ function ScanOperator(accumulator, seed, hasSeed) {
+ if (hasSeed === void 0) {
+ hasSeed = false;
+ }
+ this.accumulator = accumulator;
+ this.seed = seed;
+ this.hasSeed = hasSeed;
+ }
+ ScanOperator.prototype.call = function (subscriber, source) {
+ return source.subscribe(new ScanSubscriber(subscriber, this.accumulator, this.seed, this.hasSeed));
+ };
+ return ScanOperator;
+}());
+var ScanSubscriber = /*@__PURE__*/ (function (_super) {
+ tslib_1.__extends(ScanSubscriber, _super);
+ function ScanSubscriber(destination, accumulator, _seed, hasSeed) {
+ var _this = _super.call(this, destination) || this;
+ _this.accumulator = accumulator;
+ _this._seed = _seed;
+ _this.hasSeed = hasSeed;
+ _this.index = 0;
+ return _this;
+ }
+ Object.defineProperty(ScanSubscriber.prototype, "seed", {
+ get: function () {
+ return this._seed;
+ },
+ set: function (value) {
+ this.hasSeed = true;
+ this._seed = value;
+ },
+ enumerable: true,
+ configurable: true
+ });
+ ScanSubscriber.prototype._next = function (value) {
+ if (!this.hasSeed) {
+ this.seed = value;
+ this.destination.next(value);
+ }
+ else {
+ return this._tryNext(value);
+ }
+ };
+ ScanSubscriber.prototype._tryNext = function (value) {
+ var index = this.index++;
+ var result;
+ try {
+ result = this.accumulator(this.seed, value, index);
+ }
+ catch (err) {
+ this.destination.error(err);
+ }
+ this.seed = result;
+ this.destination.next(result);
+ };
+ return ScanSubscriber;
+}(Subscriber));
+//# sourceMappingURL=scan.js.map