import type { Result } from '../../libs/standard-result';
/**
 * A read-only lens (no `set` function) that returns an Either, with a string error message.
 * It returns an Either.Left if the lens had an error getting to the data within the given
 * structure, and an Either.Right with the value if it succeeded.
 */
export interface ResultViewLens<S, A> {
    get: (data: S) => Result<A, string>;
}
/**
 * An either view lens with no path in it
 *
 * @return
 */
export declare const id: <S>() => ResultViewLens<S, S>;
/**
 * A lens for a single path
 *
 * @param key
 * @return
 */
export declare const prop: <S, K extends keyof S>(key: K) => ResultViewLens<S, S[K]>;
/**
 * Combines two lenses to get one lens
 *
 * @param lens
 * @return
 */
export declare const composeLens: <S, A, B>(lens: ResultViewLens<A, B>) => (originalLens: ResultViewLens<S, A>) => ResultViewLens<S, B>;
export declare const fromPath: <S = any, A = any>(...path: readonly string[]) => ResultViewLens<S, A>;