@passion_pi/fp

宗旨

打造一个简单、函数式、易错误处理的异步函数库

原则

1. 高阶函数,或者有返回值的非高阶函数,返回结果均为Promise<[Error | null, Awaited<ReturnType<typeof fn>>]>
2. 无返回值函数,则返回void(视情况返回Promise<void>)
3. 单一性原则,即一个函数只做一件事
   • 减少泛型使用「泛型应使用在较为通用的集合中」

Doc

either

interface Either {
  <A extends unknown[], R>(fn: (...args: A) => R): <X = R>(
    ...args: A
  ) => Promise<[Error | null, Awaited<X>]>;
}

description

对传入的异步函数进行自动错误捕获

产生错误 => Promise<[Error, null]>

正常运行 => Promise<[null, Awaited<ReturnType<typeof fn>>]>

默认返回签名 => Promise<[Error | null, Awaited<ReturnType<typeof fn>>]>

example

import { either } from "@passion_pi/fp";

const isErr = either(() => Promise.reject("err"));
const isOk = either(() => Promise.resolve({ data: "ok" }));

var [err, data] = await isErr();
// err => Error('err'); data => never

var [err, data] = await isOk();
// err => null; data => { data: "ok" }

defer

export declare const defer: <T = unknown, E = unknown>() => {
  resolve: (data?: T | PromiseLike<T> | undefined) => void;
  reject: (msg?: E | undefined) => void;
  pending: Promise<T>;
};

description