FP Box - functional lodash style tools written in ES6

fpbox.js

// jshint esnext: true

const curry = (f) => (...a) => (a.length < f.length) ? curry(f.bind(this, ...a)) : f(...a)

const clone = (obj) => Object.assign({}, obj)

const chain = (...fs) => (a) => fs.reduce((o, f) => f(o), a)

const isEmpty = curry((a) => !a || a === null || a === '' || Object.values(a).length === 0)

const isString = curry((a) => (typeof a === 'string'))

const isNumber = (x) => !isNaN(Number(x))

const isArray = curry((a) => Array.isArray(a))

const range = curry((size) => Array(size).fill(undefined).map((x, i) => i))

const keys = curry((o) => Object.keys(o))

const values = curry((o) => Object.values(o))

const fromPairs = (arr) => arr.reduce((o, el) => { o[el[0]] = el[1]; return o }, {})

const mapValues = curry((fn, a) => Object.keys(a).reduce((o, k) => { o[k] = fn(a[k], k); return o }, {}))

const pickBy = curry((fn, a) => Object.keys(a).reduce((o, k) => { if (fn(a[k], k)) o[k] = a[k]; return o }, {}))

const reduce = curry((fn, k, a) => a.length ? a.reduce(fn, k) : Object.keys(a).reduce((o, i) => fn(o, a[i], i), k))

const filter = curry((fn, args) => args.length ? args.filter(fn) : pickBy(fn, args))

const map = curry((fn, args) => args.length ? args.map(fn) : mapValues(fn, args))

const fromPath = curry((path) => path.replace('[', '.').replace(']', '').split('.'))

const get = curry((p, a) => (isArray(p) ? p : fromPath(p)).reduce((acc, o) => acc ? acc[o] : acc, a))

const set = curry((p, value, obj) => {
  const path = isArray(p) ? p : fromPath(p)
  const next = obj[path[0]] || (isNumber(path[1]) ? [] : {})
  obj[path[0]] = path.length > 1 ? set(path.slice(1), value, next) : value
  return obj
})


console.log(
//   fromPath('the.many[0].ways'),
  chain(
    set('the.many[5].ways', 'YO'),
    get(['the', 'many', 5, 'ways'])

//     get('the.many[5].ways')
  )({})
)


// Example
// const addAll = curry((a, b) => a + b)
// const square = curry((n) => n * n)

// const a = chain(
//   addAll(2),
//   square
// )(2)
// console.log(a)

// const output = chain(
//   map((x, i) => i),
//   filter(x => x % 2)
// )(range(100))
// console.log(output)

// const obj = { a: 'foo', b: 'bar' }
// const arr = [ 'foo', 'bar' ]

// console.log(
//   map(x => x + '-', obj),
//   map(x => x + '-', arr)
// );

// console.log(
//   chain(
//     range,
//     map((x) => ['_' + x + '_', 100 + x]),
//     fromPairs,
//     map((x, i) => i + 'what'),
//     filter((x, i) => i !== '_5_'),
//     reduce((acc, x, k) => acc + k, '')
//   )(10)
// )
// console.log(isEmpty([0]))