formatPosition = pos => {
	if (pos && typeof pos === "object") {
		if ("line" in pos && "column" in pos) {
			return `${pos.line}:${pos.column}`;
		} else if ("line" in pos) {
			return `${pos.line}:?`;
		}
	}
	return "";
}
@param {SourcePosition} pos position
@returns {string} formatted position