fp-ts-io_fantasy

usingIoTS.js

import { IO } from 'fp-ts/lib/IO'
import * as io from 'fp-ts/lib/IO'
import * as array from 'fp-ts/lib/Array'
import { sequence } from 'fp-ts/lib/Traversable'

const add = (classes: string) => (sel: HTMLElement): IO<HTMLElement> => {
  return new IO(() => {
    sel.classList.add(classes)
    return sel
  })
}

const addClass = (classes: string) => (selectors: Array<HTMLElement>): IO<Array<HTMLElement>> => {
  // ios :: Array<IO<HTMLElement>>
  const ios = selectors.map(add(classes))
  // ret :: IO<Array<HTMLElement>>
  const ret = sequence(io, array)(ios)

  return ret
}
export default addClass