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- "use strict";
- var __extends = (this && this.__extends) || function (d, b) {
- for (var p in b) if (b.hasOwnProperty(p)) d[p] = b[p];
- function __() { this.constructor = d; }
- d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
- };
- var Subscriber_1 = require('../Subscriber');
- var tryCatch_1 = require('../util/tryCatch');
- var errorObject_1 = require('../util/errorObject');
- /* tslint:enable:max-line-length */
- /**
- * Returns an Observable that emits all items emitted by the source Observable that are distinct by comparison from the previous item.
- *
- * If a comparator function is provided, then it will be called for each item to test for whether or not that value should be emitted.
- *
- * If a comparator function is not provided, an equality check is used by default.
- *
- * @example <caption>A simple example with numbers</caption>
- * Observable.of(1, 1, 2, 2, 2, 1, 1, 2, 3, 3, 4)
- * .distinctUntilChanged()
- * .subscribe(x => console.log(x)); // 1, 2, 1, 2, 3, 4
- *
- * @example <caption>An example using a compare function</caption>
- * interface Person {
- * age: number,
- * name: string
- * }
- *
- * Observable.of<Person>(
- * { age: 4, name: 'Foo'},
- * { age: 7, name: 'Bar'},
- * { age: 5, name: 'Foo'})
- * { age: 6, name: 'Foo'})
- * .distinctUntilChanged((p: Person, q: Person) => p.name === q.name)
- * .subscribe(x => console.log(x));
- *
- * // displays:
- * // { age: 4, name: 'Foo' }
- * // { age: 7, name: 'Bar' }
- * // { age: 5, name: 'Foo' }
- *
- * @see {@link distinct}
- * @see {@link distinctUntilKeyChanged}
- *
- * @param {function} [compare] Optional comparison function called to test if an item is distinct from the previous item in the source.
- * @return {Observable} An Observable that emits items from the source Observable with distinct values.
- * @method distinctUntilChanged
- * @owner Observable
- */
- function distinctUntilChanged(compare, keySelector) {
- return function (source) { return source.lift(new DistinctUntilChangedOperator(compare, keySelector)); };
- }
- exports.distinctUntilChanged = distinctUntilChanged;
- var DistinctUntilChangedOperator = (function () {
- function DistinctUntilChangedOperator(compare, keySelector) {
- this.compare = compare;
- this.keySelector = keySelector;
- }
- DistinctUntilChangedOperator.prototype.call = function (subscriber, source) {
- return source.subscribe(new DistinctUntilChangedSubscriber(subscriber, this.compare, this.keySelector));
- };
- return DistinctUntilChangedOperator;
- }());
- /**
- * We need this JSDoc comment for affecting ESDoc.
- * @ignore
- * @extends {Ignored}
- */
- var DistinctUntilChangedSubscriber = (function (_super) {
- __extends(DistinctUntilChangedSubscriber, _super);
- function DistinctUntilChangedSubscriber(destination, compare, keySelector) {
- _super.call(this, destination);
- this.keySelector = keySelector;
- this.hasKey = false;
- if (typeof compare === 'function') {
- this.compare = compare;
- }
- }
- DistinctUntilChangedSubscriber.prototype.compare = function (x, y) {
- return x === y;
- };
- DistinctUntilChangedSubscriber.prototype._next = function (value) {
- var keySelector = this.keySelector;
- var key = value;
- if (keySelector) {
- key = tryCatch_1.tryCatch(this.keySelector)(value);
- if (key === errorObject_1.errorObject) {
- return this.destination.error(errorObject_1.errorObject.e);
- }
- }
- var result = false;
- if (this.hasKey) {
- result = tryCatch_1.tryCatch(this.compare)(this.key, key);
- if (result === errorObject_1.errorObject) {
- return this.destination.error(errorObject_1.errorObject.e);
- }
- }
- else {
- this.hasKey = true;
- }
- if (Boolean(result) === false) {
- this.key = key;
- this.destination.next(value);
- }
- };
- return DistinctUntilChangedSubscriber;
- }(Subscriber_1.Subscriber));
- //# sourceMappingURL=distinctUntilChanged.js.map
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