export type Predicate<T> = {
    (value: T): boolean;
    displayName?: string;
};
export type RuleFn<T> = (value: T) => string | null;
export type RuleTuple<T> = [Predicate<T>, string];
export type RuleBuilder<T> = (predicate: Predicate<T>, errorMessage?: string) => RuleFn<T>;