Modules

We have seen how impl blocks let us namespace functions to a type.

Similarly, mod lets us namespace types and functions:

1. ```
   mod foo {
   ```
2. ```
       pub fn do_something() {
   ```
3. ```
           println!("In the foo module");
   ```
4. ```
       }
   ```
5. ```
   }
   ```

7. ```
   mod bar {
   ```
8. ```
       pub fn do_something() {
   ```
9. ```
           println!("In the bar module");
   ```
10. ```
        }
    ```
11. ```
    }
    ```

13. ```
    fn main() {
    ```
14. ```
        foo::do_something();
    ```
15. ```
        bar::do_something();
    ```
16. ```
    }
    ```

This slide should take about 3 minutes.

• Packages provide functionality and include a Cargo.toml file that describes how to build a bundle of 1+ crates.
• Crates are a tree of modules, where a binary crate creates an executable and a library crate compiles to a library.
• Modules define organization, scope, and are the focus of this section.