utils.ts

export function uuidv4() {
  return "xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx".replace(/[xy]/g, function(c) {
    const r = (Math.random() * 16) | 0,
      v = c == "x" ? r : (r & 0x3) | 0x8;
    return v.toString(16);
  });
}

export function lazy<T>(value: T) {
  return () => value;
}

export function effects<V>(...fns: Consumer<V>[]) {
  return (v: V) => fns.forEach(f => f(v));
}

export function debounce<F extends AnyFunction>(fn: F, timeout: number): F {
  let timer = 0;
  const debounced =  (...args: any[]) => {
    window.clearTimeout(timer);
    timer = window.setTimeout(fn, timeout, ...args);
  };
  return debounced as F;
}

export function assert<E>(expr: E, message = "assertion failed") {
  if (!expr) throw new Error(message);
}

export function isTodo(todo: Maybe<TodoNote>): todo is TodoNote {
  return todo.type !== "Nil";
}

export { compose } from "redux";