Implementation of new generator creation from string

new_generator.js

let Generator = (function*(){}).constructor;

// function Generator(...a) {
//   let [args, body] = a;
//   if (a.length === 0) [args, body] = [[], ''];
//   if (a.length === 1) [args, body] = [[], a[0]];
//   return new Function(`return function*(${args.join(',')}){${body}};`)();
// }

// new genearator:
//
// new Generator();
// new Generator('return yield;');
// new Generator(['arg'], 'return yield arg;');