可获取

fetchable 是一个用于在 Typescript 和 JavaScript 中明确处理错误和加载的库.

安装

> npm install @attio/fetchable

概念

初级国家

有三个原始的状态 fetchable。 。 。 .

++ 完成( E)

A 类 Complete<V> 是一个简单的 JavaScript 对象,它代表任何种类的完整数据.

import {complete} from "@attio/fetchable"

const completeNumber = complete(1) // Returns a Complete<1>

console.log(completeNumber.value) // 1
console.log(completeNumber.state) // "complete"

QQ 错误

一个 Errored<E> 是另一个代表出错的 JavaScript 对象 .

import {errored} from "@attio/fetchable"

const erroredThing = errored("Oops") // Returns an Errored<"Oops">

console.log(erroredThing.error) // "Oops"
console.log(erroredThing.state) // "errored"

待定

A 类 Pending 是另一个 JavaScript 对象,它代表着一个进程正在进行中.

import {pending} from "@attio/fetchable"

const pendingThing = pending() // Returns a Pending

console.log(pendingThing.state) // "pending"

上级州

当我们开始把三个原始国家混为一谈时,乐趣就来了.

结果: 完成或出错

A 类 Result<V, E> 对象是 Complete<V> 或一个 Errored<E>它代表着 可能成功或失败的进程的结果.

import {isComplete} from "@attio/fetchable"

const result = doSynchronousThingWhichMightError() // Returns Result<number, "Oops">

if (isComplete(result)) {
    console.log(result.value) // number
} else {
    console.log(result.error) // "Oops"
}

可装入: 完成或待发

A 类 Loadable<V> 对象是 Complete<V> 或一个 Pending它代表着 同步进程的结果不能失败.

import {isComplete} from "@attio/fetchable"

const loadable = getStatusOfLongRunningProcess() // Returns Loadable<number>

if (isComplete(loadable)) {
    console.log(loadable.value) // number
}

可获取: 完成或待发或出错

A 类 Fetchable<V, E> 对象是 Complete<V>, (中文(简体) ), Errored<E> 或者说 Pending。 代表一个可能失败的同步进程的结果.

Fetchable 最常见于声明前端代码 我们不想暴露承诺.

import {isComplete, isErrored} from "@attio/fetchable"

const fetchable = getStatusOfLongRunningProcessWhichMightFail() // Returns Fetchable<number, "Oops">

if (isComplete(fetchable)) {
    console.log(fetchable.value) // number
} else if (isErrored(fetchable)) {
    console.log(fetchable.error) // "Oops"
}

同步结果

一个 AsyncResult<V, E> 是一个承诺 Result<V, E>。 。 。 . Complete<V>, (中文(简体) ), Errored<E> 或者说 Pending。 。 。 . 它常常出现在我们利用承诺进行同步进程的强制性守则中.

import {isComplete, isErrored} from "@attio/fetchable"

const asyncResult = runAsyncProcessWhichMightFail() // Returns AsyncResult<number, "Oops">

asyncResult.then(result => {
    if (isComplete(result)) {
        console.log(result.value) // number
    } else if (isErrored(result)) {
        console.log(result.error) // "Oops"
    }
})

转换

fetchable 为与这些物体合作提供功能性设施,无须明确检查 他们处于什么状态.

地图

import {map} from "@attio/fetchable"

const fetchable = getStatusOfLongRunningProcessWhichMightFail() // Returns Fetchable<number, "Oops">

// Increments the fetchable if it's complete. 
// Returns Fetchable<number, "Oops">
const incrementedFetchable = map(fetchable, (number) => number + 1)

绑定

import {map} from "@attio/fetchable"

const fetchable = getStatusOfLongRunningProcessWhichMightFail() // Returns Fetchable<number, "Oops">

// Increments the fetchable if it's complete and not zero.
// Returns Fetchable<number, "Oops" | "Unexpected zero">
const incrementedFetchable = bind(fetchable, (number) =>
    number === 0 ? errored("Unexpected zero") : complete(number + 1)
)

组合

阵列

import {combine} from "@attio/fetchable"

const fetchable1 = getStatusOfLongRunningProcessWhichMightFail() // Returns Fetchable<number, "Oops">
const fetchable2 = doSynchronousThingWhichMightError() // Returns Result<string, "Eek">

// If both fetchables are complete then their values will be returned in a complete array.
// Returns Fetchable<[number, string], "Oops" | "Eek">
const combinedFetchable = combine([fetchable1, fetchable2])

对象

import {combine} from "@attio/fetchable"

const fetchableA = getStatusOfLongRunningProcessWhichMightFail() // Returns Fetchable<number, "Oops">
const fetchableB = doSynchronousThingWhichMightError() // Returns Result<string, "Eek">

// If both fetchables are complete then their values will be returned in a new object.
// Returns Fetchable<{a: number, b: string}, "Oops" | "Eek">
const combinedFetchable = combine({a: fetchable1, b: fetchable2})

组合 Async

喜欢 Promise.all 页:1 AsyncResult编号 需要多个 AsyncResult当他们都决定 解决 Complete或当一个人与 Errored。 。 。 .

阵列

import {combineAsync} from "@attio/fetchable"

const asyncResult1 = runAsyncProcessWhichMightFail() // Returns AsyncResult<number, "Oops">
const asyncResult2 = runAnotherAsyncProcessWhichMightFail() // Returns AsyncResult<string, "Eek">

// Returns Result<[number, string], "Oops" | "Eek">
const combinedResult = await combineAsync([asyncResult1, asyncResult2])

对象

import {combine} from "@attio/fetchable"

const asyncResultA = runAsyncProcessWhichMightFail() // Returns AsyncResult<number, "Oops">
const asyncResultB = runAnotherAsyncProcessWhichMightFail() // Returns AsyncResult<string, "Eek">

// If both fetchables are complete then their values will be returned in a new object.
// Returns Result<{a: number, b: string}, "Oops" | "Eek">
const combinedResult = await combineAsync({a: asyncResultA, b: asyncResultB})