@vates/compose

Compose functions from left to right

Install

Installation of the npm package:

> npm install --save @vates/compose

Usage

import { compose } from '@vates/compose'

const add2 = x => x + 2
const mul3 = x => x * 3

// const f = x => mul3(add2(x))
const f = compose(add2, mul3)

console.log(f(5))
// → 21

The call context (this) of the composed function is forwarded to all functions.

The first function is called with all arguments of the composed function:

const add = (x, y) => x + y
const mul3 = x => x * 3

// const f = (x, y) => mul3(add(x, y))
const f = compose(add, mul3)

console.log(f(4, 5))
// → 27

Functions may also be passed in an array:

const f = compose([add2, mul3])

Options can be passed as first parameter:

const f = compose(
  {
    // compose async functions
    async: true,

    // compose from right to left
    right: true,
  },
  [add2, mul3]
)

Functions can receive extra parameters:

const isIn = (value, min, max) => min <= value && value <= max

// Only compatible when `fns` is passed as an array!
const f = compose([
  [add, 2],
  [isIn, 3, 10],
])

console.log(f(1))
// → true

Note: if the first function is defined with extra parameters, it will only receive the first value passed to the composed function, instead of all the parameters.

Contributions

Contributions are very welcomed, either on the documentation or on the code.

You may:

• report any issue you've encountered;
• fork and create a pull request.

License

ISC © Vates SAS