javascript - 将 Fluture Future 转换为民间故事结果

Question

我有以下示例代码来获取 uuid:

const Result = require('folktale/result')
const Future = require('fluture')

Future.prototype.flatMap = Future.prototype.chain

const fetch = Future.encaseP(require('node-fetch'))
const message = err => `ERROR: ${err.message}`

function getUuid () {
  return fetch('https://httpbin.org/uuid')
}

const future = getUuid()
  .map(response => {
    const responseJson = response.json.bind(response)
    const getResponseBody = Future.encaseP(responseJson)
    return getResponseBody()
  })
  .map(obj => obj.uuid)

const result = future.fold(Result.Error, Result.Ok).fork(x => x, x => x)
console.log(result) // [Function: Sequence$cancel]
result.map(
  x => {
    return message(x)
  },
  x => {
    console.log(x)
    return x
  }
)

结果不是可映射类型，当我调用 result.map 时抛出错误:

TypeError: result.map is not a function

Answer 1

fork 执行 future 并期望您处理在 fork 参数中提供的回调中的结果，更重要的是返回 cancel 函数，不是 next Future，正如您所期望的那样，我在其结果上应用了 .map。

将代码更改为:

const cancelToken = future
    .fold(Result.Error, Result.Ok)
    // if you wanna map result, do it here:
    // .map(...)
    .fork( // fork consumes the fluture and ends execution chain
        ok => message(x), 
        err => { console.log(err); }
    );
// call cancelToken() if you want to cancel it