24 lines
457 B
JavaScript
24 lines
457 B
JavaScript
|
import arityN from 'arity-n';
|
||
|
|
|
||
|
|
|
||
|
|
let compose2 = (f, g) => (...args) => f(g(...args));
|
||
|
|
|
||
|
|
export default function compose(...functions) {
|
||
|
|
|
||
|
|
const funcs = functions.filter(fn => typeof fn === 'function');
|
||
|
|
|
||
|
|
let lastIdx = funcs.length - 1;
|
||
|
|
let arity = 0;
|
||
|
|
|
||
|
|
if (funcs.length <= 0) {
|
||
|
|
throw new Error('No funcs passed');
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
if (lastIdx >= 0 && funcs[lastIdx]) {
|
||
|
|
arity = funcs[lastIdx].length;
|
||
|
|
}
|
||
|
|
|
||
|
|
return arityN(funcs.reduce(compose2), arity);
|
||
|
|
}
|