import { nat } from "./primitives.js";
export declare function freeze<V>(x: V): V;
export declare function notImplemented(): never;
export declare function privateConstructor(name: string): never;
export declare function internalError(msg?: string): never;
export declare function force<V>(value: V | undefined | null): V;
export declare function isUnicodeLetter(c: string): boolean;
export declare function isDigit(c: string): boolean;
export declare function isUnicodeDigit(c: string): boolean;
export declare function isUnicodePunctuation(c: string): boolean;
export declare function isUnicodeDelimiterOpen(c: string): boolean;
export declare function isUnicodeDelimiterClose(c: string): boolean;
export declare function isUnicodeMathSymbol(c: string): boolean;
export declare function isUnicodeSpace(c: string): boolean;
export declare function groupBy<E, G>(groupOf: (elem: E) => G, elems: Iterable<E>): [G, E[]][];
export type Printer = (line: string) => void;
export declare function timeIt<R>(label: string, op: () => R, print?: Printer): R;
export declare function assertTrue(condition: boolean, message?: string): asserts condition is true;
export declare function assertFalse(condition: boolean, message?: string): asserts condition is false;
export declare function assertNever(value: never, message?: string): never;
export declare function assertIsDefined<T>(value: T, message?: string): asserts value is NonNullable<T>;
export type NotUndefined<T> = T extends undefined ? never : T;
export type Defined = Exclude<any, undefined>;
export declare function hexString(code: nat, minLength?: nat): string;