import type { TransformFn } from '../../internal/function.js';
import { type Result } from '../core/result.js';
/**
 *  Maps a `Result<T, E>` to `Result<T, F>` by applying a _transformer_ function `mapFn<E, F>`
 *  to an contained `Err(E)` value, leaving an `Ok(T)` value untouched.
 *
 *  This function can be used to pass through a successful result while handling an error.
 */
export declare function mapErrForResult<T, E, F>(input: Result<T, E>, transformer: TransformFn<E, F>): Result<T, F>;