twittable-promise

README.md

Promise library in 137 chars

Execute in series and wait for result

// [() -> P a, a -> P b, ..., y -> P z] -> P z
P.ser([ ... ])

Execute in parallel and wait for result

// [() -> P (), ...] -> P ()
P.par([ ... ])

ex.js

const P = require('./P.js')

const delay = ms => new Promise(ok => setTimeout(ok, ms))
const log = x => () => console.log(x) 

P.ser([
  () => delay(2000).then(log('1')),
  () => delay(1500).then(log('2')),
  () => delay(1000).then(log('3'))
])
.then(() => P.par([
  () => delay(2000).then(log('3')),
  () => delay(1500).then(log('2')),
  () => delay(1000).then(log('1'))
]))
.then(() => console.log('done'))

P.js

e=exports
e.ser=x=>x.reduce((p,q)=>p?p.then(z=>q(z)):q(),0)
e.par=x=>new Promise((k,r)=>{N=x.length;x.map(p=>p().then(_=>--N?_:k(),r))})