58 lines
1.5 KiB
JavaScript
58 lines
1.5 KiB
JavaScript
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import { Subscriber } from '../Subscriber';
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export function scan(accumulator, seed) {
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let hasSeed = false;
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if (arguments.length >= 2) {
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hasSeed = true;
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}
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return function scanOperatorFunction(source) {
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return source.lift(new ScanOperator(accumulator, seed, hasSeed));
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};
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}
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class ScanOperator {
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constructor(accumulator, seed, hasSeed = false) {
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this.accumulator = accumulator;
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this.seed = seed;
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this.hasSeed = hasSeed;
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}
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call(subscriber, source) {
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return source.subscribe(new ScanSubscriber(subscriber, this.accumulator, this.seed, this.hasSeed));
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}
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}
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class ScanSubscriber extends Subscriber {
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constructor(destination, accumulator, _seed, hasSeed) {
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super(destination);
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this.accumulator = accumulator;
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this._seed = _seed;
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this.hasSeed = hasSeed;
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this.index = 0;
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}
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get seed() {
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return this._seed;
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}
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set seed(value) {
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this.hasSeed = true;
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this._seed = value;
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}
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_next(value) {
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if (!this.hasSeed) {
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this.seed = value;
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this.destination.next(value);
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}
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else {
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return this._tryNext(value);
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}
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}
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_tryNext(value) {
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const index = this.index++;
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let result;
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try {
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result = this.accumulator(this.seed, value, index);
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}
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catch (err) {
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this.destination.error(err);
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}
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this.seed = result;
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this.destination.next(result);
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}
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}
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//# sourceMappingURL=scan.js.map
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