How to use parallel() of Highland.js in stream programming to achieve parallelisation?

Question

I am trying to achieve parallelization of streams in nodejs, Following code terminates on adding parallel method in the pipeline.

let x = [1,2,3,4,5] highland(x) .map(t => t*2) .parallel(2) .each(t => console.log(t)) .done(()=> console.log('DONE'))

ERROR :

Uncaught Error: Expected Stream, got number

What is the correct way of achieving parallelization by using highlandjs ?

Answer 1

map creates a single stream, but parallel expects a stream of streams.

See examples, the second one shows parallel in action. You could try modifying that t=>t*2 function to provide its result in a one-element stream:

t=>highland([x*2])

but this is just an idea from the top of my head, I can not try it.