30 lines
No EOL
1.1 KiB
JavaScript
30 lines
No EOL
1.1 KiB
JavaScript
import { EmptyError } from '../util/EmptyError';
|
|
import { SequenceError } from '../util/SequenceError';
|
|
import { NotFoundError } from '../util/NotFoundError';
|
|
import { operate } from '../util/lift';
|
|
import { createOperatorSubscriber } from './OperatorSubscriber';
|
|
export function single(predicate) {
|
|
return operate((source, subscriber) => {
|
|
let hasValue = false;
|
|
let singleValue;
|
|
let seenValue = false;
|
|
let index = 0;
|
|
source.subscribe(createOperatorSubscriber(subscriber, (value) => {
|
|
seenValue = true;
|
|
if (!predicate || predicate(value, index++, source)) {
|
|
hasValue && subscriber.error(new SequenceError('Too many matching values'));
|
|
hasValue = true;
|
|
singleValue = value;
|
|
}
|
|
}, () => {
|
|
if (hasValue) {
|
|
subscriber.next(singleValue);
|
|
subscriber.complete();
|
|
}
|
|
else {
|
|
subscriber.error(seenValue ? new NotFoundError('No matching values') : new EmptyError());
|
|
}
|
|
}));
|
|
});
|
|
}
|
|
//# sourceMappingURL=single.js.map
|