123456789101112131415161718192021222324252627282930313233343536373839 |
- import { findIndex as higherOrder } from '../operators/findIndex';
- /**
- * Emits only the index of the first value emitted by the source Observable that
- * meets some condition.
- *
- * <span class="informal">It's like {@link find}, but emits the index of the
- * found value, not the value itself.</span>
- *
- * <img src="./img/findIndex.png" width="100%">
- *
- * `findIndex` searches for the first item in the source Observable that matches
- * the specified condition embodied by the `predicate`, and returns the
- * (zero-based) index of the first occurrence in the source. Unlike
- * {@link first}, the `predicate` is required in `findIndex`, and does not emit
- * an error if a valid value is not found.
- *
- * @example <caption>Emit the index of first click that happens on a DIV element</caption>
- * var clicks = Rx.Observable.fromEvent(document, 'click');
- * var result = clicks.findIndex(ev => ev.target.tagName === 'DIV');
- * result.subscribe(x => console.log(x));
- *
- * @see {@link filter}
- * @see {@link find}
- * @see {@link first}
- * @see {@link take}
- *
- * @param {function(value: T, index: number, source: Observable<T>): boolean} predicate
- * A function called with each item to test for condition matching.
- * @param {any} [thisArg] An optional argument to determine the value of `this`
- * in the `predicate` function.
- * @return {Observable} An Observable of the index of the first item that
- * matches the condition.
- * @method find
- * @owner Observable
- */
- export function findIndex(predicate, thisArg) {
- return higherOrder(predicate, thisArg)(this);
- }
- //# sourceMappingURL=findIndex.js.map
|