An one-line range function with JavaScript ES6, like Python

range.js

const range = (s, t = 0, a = 1) => [...Array(Math.abs(s - t))].map((x, i) => Math.min(s, t) + i * a).filter(x => x < Math.max(s, t));

console.log(range(5));
console.log(range(2, 5));
console.log(range(0, 5, 2));

// node.js: please run with `node --harmony_default_parameters --harmony range.js`