in example.rs [3:15]
fn main() {
// Open a file in read only mode in the local file system
let data_result = File::open("data.txt");
// Reading a file returns a Result enum
// Result can be a file or an error
let data_file = match data_result {
Ok(file) => file,
Err(error) => panic!("Problem opening the data file: {:?}", error),
};
println!("Data file: {:?}", data_file);
}