That's useful background information. In ECMAScript 2015, it's referred to as "proper tail calls," rather than TCO, indicating that this is important in the lan

That's useful background information. In ECMAScript 2015, it's referred to as "proper tail calls," rather than TCO, indicating that this is important in the language's design, rather than a mere performance optimization. Having proper tail calls expands the set of functions you can write without fear of overflowing the stack, so it fundamentally expands the expressiveness of the language for production use cases.