code: function isEscapeingAt(string, index) {
  	if (index === 0) { return false; }
  	let i = index - 1;
  	while (
  		i >= 0 && string[i] === '\\'
  	) { --i; }
  	return (index - i) % 2 === 0;
  }
docs: checks whether the string is escaping the char at index