enums3 solution

exercises/08_enums/enums3.rs

@@ -1,7 +1,5 @@
-// Address all the TODOs to make the tests pass!
-
 enum Message {
-    // TODO: implement the message variant types based on their usage below
+    // TODO: Implement the message variant types based on their usage below.
 }
 
 struct Point {
@@ -26,17 +24,17 @@ impl State {
     }
 
     fn echo(&mut self, s: String) {
-        self.message = s
+        self.message = s;
     }
 
-    fn move_position(&mut self, p: Point) {
-        self.position = p;
+    fn move_position(&mut self, point: Point) {
+        self.position = point;
     }
 
     fn process(&mut self, message: Message) {
-        // TODO: create a match expression to process the different message variants
+        // TODO: Create a match expression to process the different message variants.
         // Remember: When passing a tuple as a function argument, you'll need extra parentheses:
-        // fn function((t, u, p, l, e))
+        // e.g. `foo((t, u, p, l, e))`
     }
 }
 
@@ -54,8 +52,9 @@ mod tests {
             quit: false,
             position: Point { x: 0, y: 0 },
             color: (0, 0, 0),
-            message: "hello world".to_string(),
+            message: String::from("hello world"),
         };
+
         state.process(Message::ChangeColor(255, 0, 255));
         state.process(Message::Echo(String::from("Hello world!")));
         state.process(Message::Move(Point { x: 10, y: 15 }));
@@ -64,7 +63,7 @@ mod tests {
         assert_eq!(state.color, (255, 0, 255));
         assert_eq!(state.position.x, 10);
         assert_eq!(state.position.y, 15);
-        assert_eq!(state.quit, true);
+        assert!(state.quit);
         assert_eq!(state.message, "Hello world!");
     }
 }

rustlings-macros/info.toml

@@ -457,12 +457,12 @@ such as no data, anonymous structs, a single string, tuples, etc."""
 name = "enums3"
 dir = "08_enums"
 hint = """
-As a first step, you can define enums to compile this code without errors.
+As a first step, define enums to compile the code without errors.
 
-And then create a match expression in `process()`.
+Then, create a match expression in `process()`.
 
 Note that you need to deconstruct some message variants in the match expression
-to get value in the variant."""
+to get the variant's values."""
 
 # STRINGS
 

solutions/08_enums/enums3.rs

@@ -1 +1,75 @@
-// Solutions will be available before the stable release. Thank you for testing the beta version 🥰
+enum Message {
+    ChangeColor(u8, u8, u8),
+    Echo(String),
+    Move(Point),
+    Quit,
+}
+
+struct Point {
+    x: u8,
+    y: u8,
+}
+
+struct State {
+    color: (u8, u8, u8),
+    position: Point,
+    quit: bool,
+    message: String,
+}
+
+impl State {
+    fn change_color(&mut self, color: (u8, u8, u8)) {
+        self.color = color;
+    }
+
+    fn quit(&mut self) {
+        self.quit = true;
+    }
+
+    fn echo(&mut self, s: String) {
+        self.message = s;
+    }
+
+    fn move_position(&mut self, point: Point) {
+        self.position = point;
+    }
+
+    fn process(&mut self, message: Message) {
+        match message {
+            Message::ChangeColor(r, g, b) => self.change_color((r, g, b)),
+            Message::Echo(s) => self.echo(s),
+            Message::Move(point) => self.move_position(point),
+            Message::Quit => self.quit(),
+        }
+    }
+}
+
+fn main() {
+    // You can optionally experiment here.
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_match_message_call() {
+        let mut state = State {
+            quit: false,
+            position: Point { x: 0, y: 0 },
+            color: (0, 0, 0),
+            message: String::from("hello world"),
+        };
+
+        state.process(Message::ChangeColor(255, 0, 255));
+        state.process(Message::Echo(String::from("Hello world!")));
+        state.process(Message::Move(Point { x: 10, y: 15 }));
+        state.process(Message::Quit);
+
+        assert_eq!(state.color, (255, 0, 255));
+        assert_eq!(state.position.x, 10);
+        assert_eq!(state.position.y, 15);
+        assert!(state.quit);
+        assert_eq!(state.message, "Hello world!");
+    }
+}