updates to ch. 7

slides/07-managing_growing_projects_with_packages_crates_and_modules.qmd

@@ -5,11 +5,9 @@ title: "7. Managing Growing Projects with Packages, Crates, and Modules"
 
 # Learning objectives
 
-By the end of this session, you should be able to:
-
 ::: nonincremental
-- Understand and use Rust's module system (`mod`, `pub`, `use`).
 - Differentiate between packages, crates, and modules.
+- Understand and use Rust's module system (`mod`, `pub`, `use`).
 - Implement Cargo workspaces for multi-crate projects.
 - Apply best practices for managing and organizing Rust projects.
 :::
@@ -22,10 +20,10 @@ Encourage questions about any points that feel unclear.
 
 ## Key Concepts
 
-- **Package**: A bundle of one or more crates, defined by a `Cargo.toml` file.
-- **Crate**: A compilation unit in Rust (binary or library).
+- **Package**: A Cargo feature that lets you build, test and share crates. Defined by a `Cargo.toml` file.
+- **Crate**: A tree of modules that produces a library or executable. Rust's compilation unit.
 - **Module**: A way to organize code and control scope and visibility.
-- **Workspace**: A collection of interrelated packages managed together.
+- **Paths**: A way of naming an item, such as a struct, function, or module.
 
 # Creating and Using Packages
 
@@ -39,19 +37,13 @@ $ cd my_project
 - Creates a new package with a `Cargo.toml` and a default binary crate.
 - Binary crate root: `src/main.rs`.
 - To create a library crate, add a `src/lib.rs`.
-
-## Example `Cargo.toml`
-``` toml
-[package]
-name = "my_project"
-version = "0.1.0"
-edition = "2021"
-
-[dependencies]
-rand = "0.8.5"
-```
+- An executable crate must have a `main` function as an entry point.
+- A library crate can be used by other crates, and does not need a `main` entry point.
 
 # Working with Modules
+## Backyard example
+- Check out the backyard example!
+
 ## Accessing Module Items
 ``` rust
 crate::front_of_house::hosting::add_to_waitlist();
@@ -65,23 +57,36 @@ front_of_house::hosting::add_to_waitlist();
 
 ## Controlling Visibility
 ``` rust
-pub mod front_of_house {
+mod front_of_house {
     pub mod hosting {
         pub fn add_to_waitlist() {}
     }
 }
+
+pub fn eat_at_restaurant() {
+    // Absolute path
+    crate::front_of_house::hosting::add_to_waitlist();
+
+    // Relative path
+    front_of_house::hosting::add_to_waitlist();
+}
 ```
 - By default, items are private
 - Use `pub` to make modules, functions, and fields accessible
 
+## No private code in R
+- In R, everything is public 
+  - Even un-exported functions can be accessed with `:::`.
+- In Rust, private items are not accessible outside their module.
+
 # Using `use` for Convenience
 ## Simplify Paths
 ``` rust
 use crate::front_of_house::hosting;
 
 hosting::add_to_waitlist();
 ```
-- Use use to shorten paths.
+- Use `use` to shorten paths.
 - Works within the scope it's defined.
 
 ## Re-exporting with `pub use`