Compose-Function

Installation | Usage | Related | License

_{logo by Justin Mezzell}

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

Installation

npm install compose-function

Usage

Basic usage

import compose from 'compose-function';
 
const composition = compose(sqr, add2); // sqr(add2(x))
 
composition(2) // => 16
 
compose(sqr, inc)(2); // => 9
compose(inc, sqr)(2); // => 5

with curry

import compose from 'compose-function';
import { curry, _ } from 'curry-this';
 
 
const add = (x, y) => x + y;
 
// add(6, sqr(add(2, x)))
compose(
  add::curry(6),
  sqr,
  add::curry(2),
);
 
// map(filter(list, even), sqr)
compose(
  map::curry(_, sqr),
  filter::curry(_, even),
)([1,2,3,4,5,6,7,8]) // => [4, 16, 36, 64]

`::` huh?

If you’re wondering what the :: thing means, you’d better read this excellent overview by @jussi-kalliokoski or have a look at the function bind syntax proposal. Or checkout the curry-this docs.