| /** PURE_IMPORTS_START tslib,_Subscriber,_util_EmptyError PURE_IMPORTS_END */ | 
| import * as tslib_1 from "tslib"; | 
| import { Subscriber } from '../Subscriber'; | 
| import { EmptyError } from '../util/EmptyError'; | 
| export function single(predicate) { | 
|     return function (source) { return source.lift(new SingleOperator(predicate, source)); }; | 
| } | 
| var SingleOperator = /*@__PURE__*/ (function () { | 
|     function SingleOperator(predicate, source) { | 
|         this.predicate = predicate; | 
|         this.source = source; | 
|     } | 
|     SingleOperator.prototype.call = function (subscriber, source) { | 
|         return source.subscribe(new SingleSubscriber(subscriber, this.predicate, this.source)); | 
|     }; | 
|     return SingleOperator; | 
| }()); | 
| var SingleSubscriber = /*@__PURE__*/ (function (_super) { | 
|     tslib_1.__extends(SingleSubscriber, _super); | 
|     function SingleSubscriber(destination, predicate, source) { | 
|         var _this = _super.call(this, destination) || this; | 
|         _this.predicate = predicate; | 
|         _this.source = source; | 
|         _this.seenValue = false; | 
|         _this.index = 0; | 
|         return _this; | 
|     } | 
|     SingleSubscriber.prototype.applySingleValue = function (value) { | 
|         if (this.seenValue) { | 
|             this.destination.error('Sequence contains more than one element'); | 
|         } | 
|         else { | 
|             this.seenValue = true; | 
|             this.singleValue = value; | 
|         } | 
|     }; | 
|     SingleSubscriber.prototype._next = function (value) { | 
|         var index = this.index++; | 
|         if (this.predicate) { | 
|             this.tryNext(value, index); | 
|         } | 
|         else { | 
|             this.applySingleValue(value); | 
|         } | 
|     }; | 
|     SingleSubscriber.prototype.tryNext = function (value, index) { | 
|         try { | 
|             if (this.predicate(value, index, this.source)) { | 
|                 this.applySingleValue(value); | 
|             } | 
|         } | 
|         catch (err) { | 
|             this.destination.error(err); | 
|         } | 
|     }; | 
|     SingleSubscriber.prototype._complete = function () { | 
|         var destination = this.destination; | 
|         if (this.index > 0) { | 
|             destination.next(this.seenValue ? this.singleValue : undefined); | 
|             destination.complete(); | 
|         } | 
|         else { | 
|             destination.error(new EmptyError); | 
|         } | 
|     }; | 
|     return SingleSubscriber; | 
| }(Subscriber)); | 
| //# sourceMappingURL=single.js.map |