compose-function

What is compose-function?

The compose-function npm package provides utility functions for function composition, allowing you to combine multiple functions into a single function. This is particularly useful in functional programming paradigms where you want to create complex operations by combining simpler ones.

What are compose-function's main functionalities?

compose

The `compose` function allows you to combine multiple functions into a single function. In this example, `addThenMultiply` first adds 1 to the input and then multiplies the result by 2.

const compose = require('compose-function');

const add = x => x + 1;
const multiply = x => x * 2;

const addThenMultiply = compose(multiply, add);
console.log(addThenMultiply(5)); // Output: 12

pipe

The `pipe` function is similar to `compose` but applies functions from left to right. In this example, `multiplyThenAdd` first multiplies the input by 2 and then adds 1.

const { pipe } = require('compose-function');

const add = x => x + 1;
const multiply = x => x * 2;

const multiplyThenAdd = pipe(add, multiply);
console.log(multiplyThenAdd(5)); // Output: 11

Other packages similar to compose-function

lodash

Lodash is a popular utility library that provides a wide range of functions for common programming tasks, including function composition. The `_.flow` and `_.flowRight` methods in Lodash offer similar functionality to `compose` and `pipe` in compose-function.

ramda

Ramda is a functional programming library for JavaScript that emphasizes immutability and side-effect-free functions. It provides `R.compose` and `R.pipe` functions, which are similar to the compose-function package but come with additional functional programming utilities.

redux

Redux is a state management library for JavaScript applications. It includes a `compose` function that is often used to apply multiple middleware functions in a Redux store. While its primary focus is state management, its `compose` function can be used similarly to the compose-function package.

README

Compose-Function

Compose a new function from smaller functions f(g(x))

Installation

npm install compose-function

Usage

Basic usage

var compose = require('compose-function');

var composition = compose(sqr, add2); // sqr(add2(x))

composition(2) // => 16

compose(sqr, inc)(2); // => 9
compose(inc, sqr)(2); // => 5

Sweetjs

var composition = sqr ... add2; // sqr(add2(x))

composition(2) // => 16

$ sjs -m compose-function/macro yourfile.js

with curry

var compose = require('compose-function');
var curry = require('chickencurry');

function add(x, y) {
  return x + y;
}

// add(6, sqr(add(2, x)))
compose(
  curry(add, 6),
  sqr,
  curry(add, 2)
);
// or with the sweetjs macro
var myFunc = curry(add, 6) ...
             sqr ...
             curry(add, 2)

// map(filter(list, even), sqr)
compose(
  curry(map, curry.__, sqr),
  curry(filter, curry.__, even)
)([1,2,3,4,5,6,7,8]) // => [4, 16, 36, 64]