chapter 7 Modules

src/main.rs

@@ -8,10 +8,12 @@ fn main() {
     chapter_4();
     chapter_5();
     chapter_6();
+    chapter_7();
 }
 
 fn chapter_1() {
     println!("Chapter 1: Getting Started");
+    println!("`rustup update` to update rust.");
     println!("
 The compiler is named `rustc`, the package manager is `cargo`.
 Using cargo provide a lot of ease in setting up and building a rust project.
@@ -156,7 +158,7 @@ fn control_flow() {
 
     let divisor = if number % 4 == 0 {
         "Four"
-    } else if number % 3 == 0{
+    } else if number % 3 == 0 {
         "Three"
     } else if number % 2 == 0 {
         "Two"
@@ -375,7 +377,7 @@ fn first_word(s: &String) -> &str {
 
     for (i, &e) in bytes.iter().enumerate() {
         if e == b' ' {
-            return &s[0..i]
+            return &s[0..i];
         }
     }
 
@@ -389,7 +391,7 @@ fn first_word_updated(s: &str) -> &str {
 
     for (i, &e) in bytes.iter().enumerate() {
         if e == b' ' {
-            return &s[0..i]
+            return &s[0..i];
         }
     }
 
@@ -454,8 +456,8 @@ fn structs() {
     };
     println!("We can create a struct from an previous one to have it's values as default. {}", user4.active);
 
-    struct Color (i32, i32, i32);
-    struct Point (i32, i32, i32);
+    struct Color(i32, i32, i32);
+    struct Point(i32, i32, i32);
 
     let black = Color(0, 0, 0);
     let _origin = Point(0, 0, 0);
@@ -566,9 +568,12 @@ fn method_syntax() {
 }
 
 fn chapter_6() {
+    println!("Chapter 6: Enums and pattern matching");
     defining_enum();
     match_control_flow();
     concise_control_flow_if_let();
+
+    println!();
 }
 
 #[allow(dead_code)]
@@ -621,7 +626,7 @@ fn defining_enum() {
         println!("NOTE: The standard library implements an IpAddr enum, better use it than our custom one 😉.");
 
         impl IpAddr {
-            fn route(&self)  {
+            fn route(&self) {
                 // Method would be defined here
                 unimplemented!()
             }
@@ -669,13 +674,13 @@ fn match_control_flow() {
                 UsCoin::Penny => {
                     println!("Lucky penny!");
                     1
-                },
+                }
                 UsCoin::Nickel => 5,
                 UsCoin::Dime => 10,
                 UsCoin::Quarter(state) => {
                     println!("State quarter from {:?}!", state);
                     25
-                },
+                }
             }
         }
 
@@ -762,3 +767,61 @@ fn concise_control_flow_if_let() {
 
     println!();
 }
+
+fn chapter_7() {
+    println!("Chapter 7: Modules");
+    mod_and_the_filesystem();
+    controlling_visibility_with_pub();
+    referring_to_names_in_differents_modules();
+
+    println!();
+}
+
+fn mod_and_the_filesystem() {
+    println!("Modules creates namespaces. We can access module's functions with `::`.");
+    println!("We can nest modules. Modules can have the same names and functions if they don't have the same hierarchy.");
+    println!("Modules can be implementerd inline or declared and the implementation is deported in an external file.");
+    println!("The external file should be named with the name of the module: `mod toto;` => toto.rs");
+    println!("If the module has sub-modules, instead of a file we create a folder named exactly like the module with a mod.rs file in it.");
+    println!("This structure may be recursive.");
+
+    println!();
+}
+
+fn controlling_visibility_with_pub() {
+    println!("By default, modules and functions are privates. We use the `pub` keyword to make them public.");
+    println!("If an item is public, it can be accessed though any of its parent modules.");
+    println!("If an item is private, it can be accessed only by its immediate parent module and any of the parent's child modules.");
+
+    println!();
+}
+
+fn referring_to_names_in_differents_modules() {
+    println!("The `use` keyword bring a module, a function or an enum variant into the scope.");
+    println!("We can bring multiple item on the scope with a curly bracket list, or all of the item with the  `*` glob operator.");
+    // See below for a complex / coplete example.
+    println!("We can reference an element with an absolute path: `::client::connect()`.");
+    println!("We can reference an element with an relative path to the parent: `super::client::connect()`.");
+
+    println!();
+}
+
+#[allow(unused_imports, dead_code)]
+// Preparation
+mod foo {
+    pub mod bar {
+        pub type Foo = ();
+    }
+    pub mod baz {
+        pub mod quux {
+            pub type Bar = ();
+        }
+    }
+}
+
+#[allow(unused_imports, dead_code)]
+// Importing into scope
+use foo::{
+    bar::{self, Foo},
+    baz::{*, quux::Bar},
+};