+++ /dev/null
-import { Subscriber } from '../Subscriber';
-import { EmptyError } from '../util/EmptyError';
-export function single(predicate) {
- return (source) => source.lift(new SingleOperator(predicate, source));
-}
-class SingleOperator {
- constructor(predicate, source) {
- this.predicate = predicate;
- this.source = source;
- }
- call(subscriber, source) {
- return source.subscribe(new SingleSubscriber(subscriber, this.predicate, this.source));
- }
-}
-class SingleSubscriber extends Subscriber {
- constructor(destination, predicate, source) {
- super(destination);
- this.predicate = predicate;
- this.source = source;
- this.seenValue = false;
- this.index = 0;
- }
- applySingleValue(value) {
- if (this.seenValue) {
- this.destination.error('Sequence contains more than one element');
- }
- else {
- this.seenValue = true;
- this.singleValue = value;
- }
- }
- _next(value) {
- const index = this.index++;
- if (this.predicate) {
- this.tryNext(value, index);
- }
- else {
- this.applySingleValue(value);
- }
- }
- tryNext(value, index) {
- try {
- if (this.predicate(value, index, this.source)) {
- this.applySingleValue(value);
- }
- }
- catch (err) {
- this.destination.error(err);
- }
- }
- _complete() {
- const destination = this.destination;
- if (this.index > 0) {
- destination.next(this.seenValue ? this.singleValue : undefined);
- destination.complete();
- }
- else {
- destination.error(new EmptyError);
- }
- }
-}
-//# sourceMappingURL=single.js.map
\ No newline at end of file