ts_temp/function/compose.js

/**
 * Performs right-to-left function composition. The rightmost function may have
 * any arity; the remaining functions must be unary.
 *
 * **Note:** The result of compose is not automatically curried.
 *
 * @param {...Function} fns
 * @return {Function}
 * @example
 *
 *      var f = compose(x => x + 1, x => -x, Math.pow);
 *
 *      f(3, 4); // -(3^4) + 1
 */
export default ((...fns) => (...args) => {
    const n = fns.length - 1;
    let result = fns[n](...args);
    for (let i = n - 1; i >= 0; i--) {
        result = fns[i](result);
    }
    return result;
});