import { SafeUint } from 'ts-data-forge';
import { type KeepInitialValueOperator } from '../types/index.mjs';
/**
 * Transforms each value emitted by the source using a mapping function that also receives the emission index.
 *
 * @template A - The type of values from the source
 * @template B - The type of mapped values
 * @param mapFn - A function that maps each value (receives value and index)
 * @returns An operator that maps values with index
 *
 * @example
 * ```ts
 * //  Timeline:
 * //
 * //  num$      "A"      "B"      "C"
 * //  indexed$  "0: A"   "1: B"   "2: C"
 * //
 * //  Explanation:
 * //  - mapWithIndex transforms each value along with its index
 * //  - Index starts at 0 and increments with each emission
 *
 * const num$ = source<string>();
 *
 * const indexed$ = num$.pipe(map((x, i) => `${i}: ${x}`));
 *
 * const valueHistory: string[] = [];
 *
 * indexed$.subscribe((s) => {
 *   valueHistory.push(s);
 * });
 *
 * num$.next('A'); // 0: A
 *
 * num$.next('B'); // 1: B
 *
 * num$.next('C'); // 2: C
 *
 * assert.deepStrictEqual(valueHistory, ['0: A', '1: B', '2: C']);
 * ```
 */
export declare const map: <A, B>(mapFn: (x: A, index: SafeUint | -1) => B) => KeepInitialValueOperator<A, B>;
//# sourceMappingURL=map.d.mts.map