54 lines
No EOL
1.6 KiB
JavaScript
54 lines
No EOL
1.6 KiB
JavaScript
import { Subscriber } from '../Subscriber';
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export function distinctUntilChanged(compare, keySelector) {
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return (source) => source.lift(new DistinctUntilChangedOperator(compare, keySelector));
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}
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class DistinctUntilChangedOperator {
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constructor(compare, keySelector) {
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this.compare = compare;
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this.keySelector = keySelector;
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}
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call(subscriber, source) {
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return source.subscribe(new DistinctUntilChangedSubscriber(subscriber, this.compare, this.keySelector));
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}
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}
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class DistinctUntilChangedSubscriber extends Subscriber {
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constructor(destination, compare, keySelector) {
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super(destination);
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this.keySelector = keySelector;
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this.hasKey = false;
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if (typeof compare === 'function') {
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this.compare = compare;
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}
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}
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compare(x, y) {
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return x === y;
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}
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_next(value) {
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let key;
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try {
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const { keySelector } = this;
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key = keySelector ? keySelector(value) : value;
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}
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catch (err) {
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return this.destination.error(err);
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}
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let result = false;
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if (this.hasKey) {
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try {
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const { compare } = this;
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result = compare(this.key, key);
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}
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catch (err) {
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return this.destination.error(err);
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}
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}
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else {
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this.hasKey = true;
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}
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if (!result) {
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this.key = key;
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this.destination.next(value);
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}
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}
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}
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//# sourceMappingURL=distinctUntilChanged.js.map
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