it-pipe

Utility to "pipe" async iterables together

Based on this definition of streaming iterables https://gist.github.com/alanshaw/591dc7dd54e4f99338a347ef568d6ee9.

Almost identical to the pipeline function from the streaming-iterables module except that it supports duplex streams and will automatically wrap a "source" as the first param in a function.

Install

npm i it-pipe

Usage

import { pipe } from 'it-pipe'

const result = await pipe(
  // A source is just an iterable, this is shorthand for () => [1, 2, 3]
  [1, 2, 3],
  // A transform takes a source, and returns a source.
  // This transform doubles each value asynchronously.
  function transform (source) {
    return (async function * () { // A generator is async iterable
      for await (const val of source) yield val * 2
    })()
  },
  // A sink, it takes a source and consumes it, optionally returning a value.
  // This sink buffers up all the values from the source and returns them.
  async function collect (source) {
    const vals = []
    for await (const val of source) {
      vals.push(val)
    }
    return vals
  }
)

console.log(result) // 2,4,6

API

pipe(firstFn, ...fns)

Calls firstFn and then every function in fns with the result of the previous function. The final return is the result of the last function in fns.

Note:

• firstFn may be a Function or an Iterable
• firstFn or any of fns may be a duplex object (an object with a sink and source).

Contribute

Feel free to dive in! Open an issue or submit PRs.

License

MIT © Alan Shaw