import { Vector } from "@fncts/base/collection/immutable/Vector";
import type { IndexSignature, TemplateLiteral } from "./AST";
export declare function memoize<A, B>(f: (a: A) => B): (a: A) => B;
export declare function ownKeys(o: object | undefined): Vector<PropertyKey>;
export declare function getTemplateLiteralRegex(ast: TemplateLiteral): RegExp;
export declare function getKeysForIndexSignature(input: {
    readonly [x: PropertyKey]: unknown;
}, parameter: IndexSignature["parameter"]): Vector<string> | Vector<symbol>;
export declare function formatUnknown(u: unknown): string;