funcom

Functional composition helpers.

Install

yarn add funcom

API

compose

Sequential composition of functions invoked in reverse order. Passes return value of the previous function as an argument to the next one.

import { compose } from 'funcom'

const add4 = (a: number) => a + 4
const mult2 = (a: number) => a * 2

const composed = compose(mult2, add4)

console.log(
  composed(2)
)
// (2 + 4) * 2 => 12

composeAsync

import { composeAsync } from 'funcom'

const add4Async= (arg: number) => Promise.resolve(arg + 40)
const mult2 = (a: number) => a * 2

const composed = composeAsync(mult2, add4Async)

console.log(
  await composed(2)
)
// (2 + 4) * 2 => 12

pipe

Sequential composition of functions invoked in direct order. Passes return value of the previous function as an argument to the next one.

import { pipe } from 'funcom'

const add4 = (a: number) => a + 4
const mult2 = (a: number) => a * 2

const piped = pipe(mult2, add4)

console.log(
  piped(2)
)
// (2 * 2) + 4 => 8

pipeAsync

import { pipeAsync } from 'funcom'

const mult2Async = (a: number) => Promise.resolve(a * 2)
const add4 = (a: number) => a + 4

const piped = pipeAsync(mult2Async, add4)

console.log(
  await piped(2)
)
// (2 * 2) + 4 => 8

all

Composition of multiple functions invoked with same initial value. Returns an array of results.

import { all } from 'funcom'

const mult2 = (a: number) => a * 2
const add4 = (a: number) => a + 4
const toString = (a: number) => `${a}`

const piped = all(mult2, add4, toString)

console.log(
  piped(2)
)
// [8, 6, '2']

allAsync

import { allAsync } from 'funcom'

const mult2 = (a: number) => a * 2
const add4 = (a: number) => a + 4
const toStringAsync = (a: number) => Promise.resolve(`${a}`)

const piped = allAsync(mult2Async, add4, toStringAsync)

console.log(
  await piped(2)
)
// [8, 6, '2']