import { MapDiff, ListDiff, ScalarDiff } from '@aws-cdk/service-spec-types';
export declare function diffByKey<A, B>(a: A[], b: A[], keyFn: (x: A) => string, updatedDiff: (a: A, b: A) => B | undefined): MapDiff<A, B>;
export declare function diffMap<A, B>(a: Record<string, A>, b: Record<string, A>, updatedDiff: (a: A, b: A) => B | undefined): MapDiff<A, B>;
/**
 * Diff a list by quadratically comparing all elements
 */
export declare function diffList<A, B>(as: A[], bs: A[], eq: Eq<A>, updatedDiff: (a: A, b: A) => B | undefined): ListDiff<A, B>;
export declare function diffList<A, B>(as: A[], bs: A[], eq: Eq<A>): ListDiff<A, void>;
export declare function tripleEq<A>(a: A, b: A): boolean;
export declare function jsonEq<A>(a: A, b: A): boolean;
export declare function diffScalar<A extends object, K extends keyof A>(a: A, b: A, k: K, defaultValue?: A[K]): A[K] extends string | number | boolean | undefined ? ScalarDiff<NonNullable<A[K]>> | undefined : void;
export declare function diffField<A extends object, K extends keyof A>(a: A, b: A, k: K, eq: Eq<A[K]>, defaultValue?: A[K]): ScalarDiff<NonNullable<A[K]>> | undefined;
/**
 * Return the object if it has any defined fields, otherwise undefined
 */
export declare function collapseUndefined<A extends object>(x: A): A | undefined;
export declare function collapseEmptyDiff<A extends ListDiff<any, any> | MapDiff<any, any>>(x: A): A | undefined;
export type Eq<A> = (x: A, y: A) => boolean;
export type AllFieldsGiven<A extends object> = {
    [k in keyof Required<A>]: A[k];
};