| import { Operator } from '../Operator'; |
| import { Subscriber } from '../Subscriber'; |
| import { OperatorFunction } from '../types'; |
| /** |
| * Applies a given `project` function to each value emitted by the source |
| * Observable, and emits the resulting values as an Observable. |
| * |
| * <span class="informal">Like [Array.prototype.map()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/map), |
| * it passes each source value through a transformation function to get |
| * corresponding output values.</span> |
| * |
| * ![](map.png) |
| * |
| * Similar to the well known `Array.prototype.map` function, this operator |
| * applies a projection to each value and emits that projection in the output |
| * Observable. |
| * |
| * ## Example |
| * Map every click to the clientX position of that click |
| * ```ts |
| * import { fromEvent } from 'rxjs'; |
| * import { map } from 'rxjs/operators'; |
| * |
| * const clicks = fromEvent(document, 'click'); |
| * const positions = clicks.pipe(map(ev => ev.clientX)); |
| * positions.subscribe(x => console.log(x)); |
| * ``` |
| * |
| * @see {@link mapTo} |
| * @see {@link pluck} |
| * |
| * @param {function(value: T, index: number): R} project The function to apply |
| * to each `value` emitted by the source Observable. The `index` parameter is |
| * the number `i` for the i-th emission that has happened since the |
| * subscription, starting from the number `0`. |
| * @param {any} [thisArg] An optional argument to define what `this` is in the |
| * `project` function. |
| * @return {Observable<R>} An Observable that emits the values from the source |
| * Observable transformed by the given `project` function. |
| * @method map |
| * @owner Observable |
| */ |
| export declare function map<T, R>(project: (value: T, index: number) => R, thisArg?: any): OperatorFunction<T, R>; |
| export declare class MapOperator<T, R> implements Operator<T, R> { |
| private project; |
| private thisArg; |
| constructor(project: (value: T, index: number) => R, thisArg: any); |
| call(subscriber: Subscriber<R>, source: any): any; |
| } |