Concurrency

QIO data structure provide various operators that can help manage concurrency.

.and()

Serial execution of effects can be performed through the and operator for eg:

import {QIO} from '@qio/core'
const putStrLn = QIO.encase(console.log)

const foo = putStrLn('foo')
const bar = putStrLn('bar')

export const main = (): QIO<void, never, unknown> => {
  return foo.and(bar)
}

.chain()

Sometimes its necessary to consume the response of the previous result to produce the effect. This can be done using the chain operator:

export const main = (): QIO<void, never, unknown> => {
  return getStrLn('Enter name:').chain(name =>
    putStrLn('Welcome to the world of fp ' + name)
  )
}

.par()

Similar to the and operator, the par operator helps run the two effects in parallel. For eg.:

import {QIO} from '@qio/core'

const foo = QIO.timeout('foo', 1000)
const bar = QIO.timeout('bar', 1500)

const fooBar = foo.par(bar)

The program fooBar completes in 1500ms because both are executed in parallel.

.race()

Race allows two QIO instances to run in parallel and respond with the the one that completes/fails first. The one that is pending automatically gets cancelled.

import {QIO} from '@qio/core'

const foo = QIO.timeout('foo', 1000)
const bar = QIO.timeout('bar', 1500)

const fooBar = foo.race(bar)