Parsing a string to a point may not be successful, and we were able to communicate that to users of parse_point() by returning a custom type called point_or_error_t. What if we want to parse not just one point but a set of points, forming a polyline, from a list of strings? The result of parsing each string separately is a point or an error. Only if the list of those point_or_error_t values contains no error at all should we consider turning the points into a polyline. If any of the values is...
