ch6 done

ch6/book_match/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "book_match"
+version = "0.1.0"

ch6/book_match/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "book_match"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

ch6/book_match/src/main.rs

@@ -0,0 +1,76 @@
+enum Coin {
+    Penny,
+    Nickel,
+    Dime,
+    Quarter,
+}
+
+#[derive(Debug)]
+enum UsState {
+    California,
+    Alabama,
+    Missouri,
+    // so on and so forth
+}
+
+enum StateCoin {
+    Penny,
+    Nickel,
+    Dime,
+    Quarter(UsState),
+}
+
+fn main() {
+    let five = Some(5);
+    let six = plus_one(five);
+    let none = plus_one(None);
+
+    let dice_roll = 9;
+    match dice_roll {
+        3 => add_fancy_hat(),
+        7 => remove_fancy_hat(),
+        _ => (), // just like Haskell! Can tell Rust that no code should be ran with ()
+    }
+}
+
+fn value_in_cents(coin: Coin) -> u8 {
+    match coin {
+        Coin::Penny => {
+            // can use curly brackets :)
+            println!("Lucky Penny");
+            1
+        }
+        Coin::Nickel => 5,
+        Coin::Dime => 10,
+        Coin::Quarter => 25,
+    }
+}
+
+fn value_in_cents_state(coin: StateCoin) -> u8 {
+    match coin {
+        StateCoin::Penny => {
+            // can use curly brackets :)
+            println!("Lucky Penny");
+            1
+        }
+        StateCoin::Nickel => 5,
+        StateCoin::Dime => 10,
+        StateCoin::Quarter(state) => {
+            println!("State quarter from {state:?}!");
+            25
+        }
+    }
+}
+
+fn plus_one(x: Option<i32>) -> Option<i32> {
+    // match arms must cover all possibilities
+    match x {
+        None => None,
+        Some(i) => Some(i + 1),
+    }
+}
+
+fn add_fancy_hat() {}
+fn remove_fancy_hat() {}
+fn move_player(num_spaces: u8) {}
+fn reroll() {}

ch6/defining_an_enum/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "defining_an_enum"
+version = "0.1.0"

ch6/defining_an_enum/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "defining_an_enum"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

ch6/defining_an_enum/src/main.rs

@@ -0,0 +1,78 @@
+// I could make an emum for a buy/sell/hold signal in a long-only strategy
+// cool project from the android team at google:
+//   https://google.github.io/comprehensive-rust/
+
+enum IpAddrKind {
+    V4,
+    V6,
+}
+
+struct IpAddrOld {
+    kind: IpAddrKind,
+    address: String,
+}
+
+// A better way of representing IP in this case
+enum IpAddrFunc {
+    V4(String),
+    V6(String),
+}
+
+// Even better way as these enums can hold
+// different values, like a tuple, and like Haskell
+enum IpAddr {
+    V4(u8, u8, u8, u8),
+    V6(String),
+}
+
+enum Message {
+    Quit,
+    Move { x: i32, y: i32 },
+    Write(String),
+    ChangeColor(i32, i32, i32),
+}
+
+impl Message {
+    fn call(&self) {
+        // method body here
+    }
+}
+
+fn main() {
+    let four = IpAddrKind::V4;
+    let six = IpAddrKind::V6;
+
+    route(four);
+    route(six);
+
+    let home_old: IpAddrOld = IpAddrOld {
+        kind: IpAddrKind::V4,
+        address: String::from("127.0.0.1"),
+    };
+
+    let loopback_old = IpAddrOld {
+        kind: IpAddrKind::V6,
+        address: String::from("::1"),
+    };
+
+    let home = IpAddrFunc::V4(String::from("127.0.0.1"));
+    let loopback = IpAddrFunc::V6(String::from("::1"));
+
+    let home_num = IpAddr::V4(127, 0, 0, 1);
+
+    // Message section
+
+    let m = Message::Write(String::from("hello"));
+    m.call();
+
+    // ------------------------------------------------------------------------------
+    // Option enum section
+    // Essentially Haskell's Maybe Monad
+    // Rust even has a Prelude :pog:
+    let some_number = Some(5);
+    let some_char = Some('e');
+    let absent_number: Option<i32> = None;
+}
+
+// takes either kind of IpAddrKind
+fn route(ip_kind: IpAddrKind) {}

ch6/if_let/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "if_let"
+version = "0.1.0"

ch6/if_let/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "if_let"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

ch6/if_let/src/main.rs

@@ -0,0 +1,18 @@
+// More verboseness
+
+fn main() {
+    let config_max = Some(3u8);
+    if let Some(max) = config_max {
+        println!("Max configured to be: {max}");
+    }
+    // else would be what goes in the _
+}
+
+// fn make_sep(usr_str: &str) -> &str {
+//     if usr_str == "" {
+//         let default = "=".repeat(10);
+//         &default
+//     } else {
+//         usr_str
+//     }
+// }