function find_closing_parenthesis(start, code) {
	let parenthesis = 1;
	let end = start;
	let char = code[end];
	// find the closing parenthesis
	while (parenthesis !== 0 && char) {
		if (char === '(') parenthesis++;
		if (char === ')') parenthesis--;
		end++;
		char = code[end];
	}
	return end;
}
@param {number} start
@param {string} code