export declare function isSpace(char: string): boolean;
export declare function isAlpha(char: string): boolean;
export declare function preprocessInput(input: string): string;
export declare type opaque = {} | void;
export declare type Option<T> = T | null;
export declare type Maybe<T> = Option<T> | undefined | void;
export declare function unwrap<T>(maybe: Maybe<T>, msg?: string): T;
export declare function or<T, U>(maybe: Maybe<T>, otherwise: U): T | U;