eithers-utils.js

const r = require('ramda')

const lefts = r.reduce(
  (memo, either) => {
    let extract
    either.bimap(x => extract = x, r.identity)
    return extract ? r.append(extract, memo) : memo
  },
  []
)

const rights = r.reduce(
  (memo, either) => {
    let extract
    either.bimap(r.identity, x => extract = x)
    return extract ? r.append(extract, memo) : memo
  },
  []
)