X-Git-Url: https://git.ralfj.de/rust-101.git/blobdiff_plain/63b086dfbd9a5e90700f595c2e6ef7ee10522559..4816335a8c0e5bcb2514d9c7857596348fa72ff4:/src/part03.rs diff --git a/src/part03.rs b/src/part03.rs index ddaa47e..0e7db1d 100644 --- a/src/part03.rs +++ b/src/part03.rs @@ -56,14 +56,15 @@ fn read_vec() -> Vec { // of the function), but that's a bit too much magic for my taste. We are being more explicit here: // `parse::` is `parse` with its generic type set to `i32`. match line.parse::() { - // `parse` returns again a `Result`, and this time we use a `match` to handle errors (like, the user entering - // something that is not a number). - // This is a common pattern in Rust: Operations that could go wrong will return `Option` or `Result`. - // The only way to get to the value we are interested in is through pattern matching (and through helper functions - // like `unwrap()`). If we call a function that returns a `Result`, and throw the return value away, - // the compiler will emit a warning. It is hence impossible for us to *forget* handling an error, - // or to accidentally use a value that doesn't make any sense because there was an error producing it. + // `parse` returns again a `Result`, and this time we use a `match` to handle errors (like, the user entering + // something that is not a number). + // This is a common pattern in Rust: Operations that could go wrong will return `Option` or `Result`. + // The only way to get to the value we are interested in is through pattern matching (and through helper functions + // like `unwrap()`). If we call a function that returns a `Result`, and throw the return value away, + // the compiler will emit a warning. It is hence impossible for us to *forget* handling an error, + // or to accidentally use a value that doesn't make any sense because there was an error producing it. Ok(num) => vec.push(num), + // We don't care about the particular error, so we ignore it with a `_`. Err(_) => println!("What did I say about numbers?"), } } @@ -76,7 +77,7 @@ fn read_vec() -> Vec { // as the documentation is quite easy to navigate and you should get used to that. // For the rest of the code, we just re-use part 02 by importing it with `use`. -// I already sneaked a bunch of `pub` in the other module to make this possible: Only +// I already sneaked a bunch of `pub` in part 02 to make this possible: Only // items declared public can be imported elsewhere. use part02::{SomethingOrNothing,Something,Nothing,vec_min}; @@ -103,7 +104,7 @@ trait Print { } impl SomethingOrNothing { fn print2(self) { - panic!("Not yet implemented.") + unimplemented!() } }