change to struct

src/main.rs

@@ -1,6 +1,17 @@
+use std::{fmt::Display, ops::Index};
+
 use rand::Rng;
 
-type State = [bool; 8];
+#[derive(Debug, Clone, Copy)]
+struct State([bool; 8]);
+
+impl Index<usize> for State {
+    type Output = bool;
+
+    fn index(&self, index: usize) -> &Self::Output {
+        &self.0[index]
+    }
+}
 
 fn map_state(rule: u8, state: &State) -> State {
     let mut new_state: [bool; 8] = [false; 8];
@@ -12,21 +23,29 @@ fn map_state(rule: u8, state: &State) -> State {
         new_state[i] = (rule >> pattern & 1) == 1;
     }
 
-    new_state
+    State(new_state)
 }
 
-fn state_to_string(state: State) -> String {
-    state.map(|c| if c { "⬛" } else { "⬜" }).concat()
+impl Display for State {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(
+            f,
+            "{}",
+            self.0.map(|c| if c { "⬛" } else { "⬜" }).concat()
+        )
+    }
 }
 
-fn num_to_state(num: u8) -> State {
-    let mut state = [false; 8];
+impl Into<State> for u8 {
+    fn into(self) -> State {
+        let mut state = [false; 8];
 
-    for i in 0..8 {
-        state[i] = (num >> i & 1) == 1;
-    }
+        for i in 0..8 {
+            state[i] = (self >> i & 1) == 1;
+        }
 
-    state
+        State(state)
+    }
 }
 
 fn main() {
@@ -34,7 +53,7 @@ fn main() {
     let seed: u16 = rng.gen();
 
     let rule: u8 = (seed & 0xff) as u8;
-    let init_state = num_to_state((seed >> 8 & 0xff) as u8);
+    let init_state = ((seed >> 8 & 0xff) as u8).into();
 
     let states: String = (0..8)
         .scan(init_state, |state, _i| {
@@ -42,7 +61,7 @@ fn main() {
             *state = map_state(rule, state);
             Some(old_state)
         })
-        .map(state_to_string)
+        .map(|state| state.to_string())
         .collect::<Vec<String>>()
         .join("\n");