promise-stream

A stream interface for representing data flows with support for promises. Good for representing a value that can be recomputed. API inspired by flyd.

Installation

$ npm install @f/promise-stream

Usage

import stream from '@f/promise-stream'

var s = stream(delay(10, 1))

co(function * () {
  yield stream.wait(s) // 1
  yield stream.wait(s) // 1
  s(delay(10, 2))
  yield stream.wait(s) // 2
})

var in1 = stream(1)
var in2 = stream(1)

var add = stream.combine(function (arg1, arg2) {
  return arg1 + arg2
}, [in1, in2])

co(function * () {
  yield stream.wait(add) // 2
  yield stream.wait(add) // 2
  in1(delay(10, 2))
  yield stream.wait(add) // 3
})

function delay (d, last) {
  return new Promise(function (resolve) {
    setTimeout(function () {
      resolve(last)
    }, d)
  })
}

API

stream(initial)

• initial - initial value for stream

Returns: function for pushing vals on to the stream

stream.wait(s)

• s - stream wait on

Returns: Returns val of steam after all pending promises have been resolved.

stream.on(fn, s)

• fn - listen for updates to stream s
• s - stream instance

stream.map(fn, s)

• fn - mapping function on values in stream s
• s - stream instance

Returns: a new stream

stream.combine(fn, deps)

• fn - mapping function over values in streams deps
• deps - streams that fn depends on

Returns: a new stream

License

MIT