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--- devlogs:14_5_2022 [2022/05/14 19:43]
root
+++ devlogs:14_5_2022 [2023/10/19 15:25] (current)
@@ Line 13: / Line 13: @@
  name:(String),
  color:(u8,u8,u8), //Tuples can be stored
- //I DONT THING YOU CAN NEST ENUMS..... lmk bois
+ //I DONT THINK YOU CAN NEST ENUMS..... lmk bois
 }
 </code>
@@ Line 49: / Line 49: @@
 </code>
 this is how you can make a class with structs. The Declaration of the struct is like a C++ header file and the impl like the cpp file ((not really)).
+YOU caaaaaan also deconstruct structs but I didnt havtadoit for the exercises so idkfa.
 ==== Enums ====
+Enums are another grouping of data. One major difference between enums and structs is that with structs you MUST initialize every value when you instance it. With an enum you can only pick one of its possible values while instancing. Usually its used when you have different options and can pick one(variants). [[https://github.com/rust-lang/rustlings/tree/main/exercises/enums|EG FROM THE BOOK]]
+<code rust>
+enum Message {
+    ChangeColor(u8,u8,u8),
+    Echo(String),
+    Move{x:u8,y:u8},
+    Quit,
+}
+</code>
+This enum has for variants and each one hold a different type. This way our one message enum can deal with many use cases rather than having different overloaded functions.
+We can use "matching" to go through every value (enumerate) and perform different actions based on the value matched.
+<code rust>
+ let message = Message::Quit;
+ match message{
+  Message::Move{x,y} => {self.move_position(Point{x,y});}
+  Message::Echo(message) => {self.echo(message);}
+  Message::ChangeColor(h,s,v) => {self.change_color((h,s,v));}
+  Message::Quit => {self.quit();}
+ }
+</code>
+**EZ PZZ** <wrap lo>probabbly more nuacnces than that tho</wrap> **squeeqzy**
+Matches must be **EXHAUSTIVE**.. or rust mama will yell.
+The two other special matching cases are __other__ and _____.
+[[https://doc.rust-lang.org/book/ch06-02-match.html| FR☺M THE RUST B☺☺K ]]
+<code rust>
+let dice_roll = 9;
+match dice_roll {
+=> add_fancy_hat(),
+=> remove_fancy_hat(),
+ other => move_player(other),
+}
+fn add_fancy_hat() {}
+fn remove_fancy_hat() {}
+fn move_player(num_spaces: u8) {}
+</code>
+Here the values 3 and 7 are covered. ALL OTHER VALUES ARE EVALUATED AS OTHER. We can also use _ which kind of does the same thing but will also work with values that are non-valid.
+<code rust>
+let dice_roll = 9
+match dice_roll {
+=> add_fancy_hat(),
+=> remove_fancy_hat(),
+ _ => (), // the () is an empty tuple and basically says "Yo, mr.code don't do anything".
+}
+fn add_fancy_hat() {}
+fn remove_fancy_hat() {}
+</code>
 ==== Modules ====
+Modules help break up code into reusable chunks. Kind of like namespaces.
+**A module is a collection of items: functions, structs, traits, impl and other modules.**
+Creating a module [[https://github.com/rust-lang/rustlings/tree/main/exercises/modules| FROM RUSTLINGS]]
+<code rust>
+mod sausage_factory {
+ // Don't let anybody outside of this module see this!
+ fn get_secret_recipe() -> String {
+  String::from("Ginger")
+ }
+ pub fn make_sausage() {
+  get_secret_recipe();
+  println!("sausage!");
+ }
+}
+fn main() {
+    sausage_factory::make_sausage();
+}
+</code>
+Another thing we can do with modules is bring them into scope to use them with shorthand names. This can be done with the **use .. as** syntax.
+<code rust>
+use std::time::UNIX_EPOCH as UNIX_EPOCH;
+use std::time::SystemTime as SystemTime;
+fn main() {
+ match SystemTime::now().duration_since(UNIX_EPOCH) {
+  Ok(n) => println!("1970-01-01 00:00:00 UTC was {} seconds ago!", n.as_secs()),
+  Err(_) => panic!("SystemTime before UNIX EPOCH!"),
+ }
+}
+</code>
+Yea man thats basically about it... why are you (([[https://www.youtube.com/watch?v=2HOClc6Svg4|here]]))
-~~ DISCUSSION | F's ~~
+~~DISCUSSION | F's ~~

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