lookup = (parent, mod) => {
	if (mod.charAt(0) !== ".") return mod;

	const path = parent.split("/");
	const segments = mod.split("/");
	path.pop();

	for (let i = 0; i < segments.length; i++) {
		const seg = segments[i];
		if (seg === "..") {
			path.pop();
		} else if (seg !== ".") {
			path.push(seg);
		}
	}

	return path.join("/");
}
@param {string} parent parent module
@param {string} mod module to resolve
@returns {string} resolved module