export type tillFn          = (dones: boolean[]) => boolean;
export type reduceFn<T, U>  = (acc: U, v: T, i: number, x: Iterable<T>) => U;
export type calledFn<T>     = (v: T, i: number, x: Iterable<T>) => void;
export type testFn<T>       = (v: T, i: number, x: Iterable<T>) => boolean;
export type mapFn<T, U>     = (v: T, i: number, x: Iterable<T>) => U;
export type combineFn<T>    = (a: T, b: T) => T;
export type compareFn<T>    = (a: T, b: T) => number;
export type getFn<T>        = () => T;
export type Entries<T>      = Iterable<[number, T]>;
export type Lists<T>        = [Iterable<number>, Iterable<T>];