//@ immutable per default, and you need to tell Rust if you want
//@ to change a variable later.
- // Now we want to *iterate* over the list. Rust has some nice syntax for
- // iterators:
+ // Now we want to *iterate* over the list. Rust has some nice syntax for iterators:
for el in vec {
- // So `el` is al element of the list. We need to update `min` accordingly, but how do we get the current
+ // So `el` is an element of the list. We need to update `min` accordingly, but how do we get the current
// number in there? This is what pattern matching can do:
match min {
// In this case (*arm*) of the `match`, `min` is currently nothing, so let's just make it the number `el`.
min = NumberOrNothing::Number(new_min); /*@*/
}
}
+ //@ Notice that Rust makes sure you did not forget to handle any case in your `match`. We say
+ //@ that the pattern matching has to be *exhaustive*.
}
// Finally, we return the result of the computation.
return min;
// Indeed, we can: The following line tells Rust to take
// the constructors of `NumberOrNothing` into the local namespace.
-// Try moving that above the function, and removing all the occurrences `NumberOrNothing::`.
+// Try moving that above the function, and removing all the occurrences of `NumberOrNothing::`.
use self::NumberOrNothing::{Number,Nothing};
// To call this function, we now just need a list. Of course, ultimately we want to ask the user for
// a list of numbers, but for now, let's just hard-code something.
-//@ `vec!` is a *macro* (as you can tell from the `!`) that constructs a constant `Vec<_>` with the given
+//@ `vec!` is a *macro* (as indicated by `!`) that constructs a constant `Vec<_>` with the given
//@ elements.
fn read_vec() -> Vec<i32> {
vec![18,5,7,1,9,27] /*@*/
}
-// Finally, let's call our functions and run the code!
-// But, wait, we would like to actually see something, so we need to print the result.
+// Of course, we would also like to actually see the result of the computation, so we need to print the result.
//@ Of course Rust can print numbers, but after calling `vec_min`, we have a `NumberOrNothing`.
//@ So let's write a small helper function that prints such values.
print_number_or_nothing(min);
}
-// You can now use `cargo build` to compile your code. If all goes well, try `cargo run` on the
-// console to run it.
+//@ You can now use `cargo build` to compile your *crate*. That's Rust's name for a *compilation unit*, which in
+//@ the case of Rust means an application or a library. <br/>
+// Finally, try `cargo run` on the console to run it.
//@ Yay, it said "1"! That's actually the right answer. Okay, we could have
-//@ computed that ourselves, but that's besides the point. More importantly:
+//@ computed that ourselves, but that's beside the point. More importantly:
//@ You completed the first part of the course.
-//@ [index](main.html) | previous | [next](part01.html)
+//@ [index](main.html) | previous | [raw source](workspace/src/part00.rs) | [next](part01.html)