improved command parsing

src/day10/mod.rs

@@ -7,11 +7,22 @@ enum Command {
 }
 impl Command {
     fn from_str(s: &str) -> Self {
-        if s == "noop" {
-            Self::Noop
-        } else {
-            let sp = s.split_once(' ').unwrap();
-            Self::AddX(sp.1.parse().unwrap())
+        match s {
+            "noop" => Command::Noop,
+            s => {
+                let (c, i) = s.split_once(' ').unwrap();
+                match (c, i.parse::<i32>()) {
+                    ("addx", Ok(i)) => Self::AddX(i),
+                    _ => unreachable!(),
+                }
+            }
+        }
+    }
+
+    fn num_cycles(&self) -> usize {
+        match self {
+            Self::Noop => 1,
+            Self::AddX(_) => 2,
         }
     }
 }
@@ -32,9 +43,11 @@ pub fn run() {
     let mut pixels = [false; LINE_WIDTH];
     let mut rows = vec![];
     'outer: loop {
+        // Part 1
         if cycle == 20 || (cycle > 20 && (cycle - 20) % LINE_WIDTH == 0) {
             sig_str.push(cycle as i32 * v);
         }
+
         if is_busy == 0 {
             match lines.next() {
                 Some(s) => {
@@ -43,17 +56,16 @@ pub fn run() {
                         Command::Noop => {}
                         Command::AddX(x) => {
                             v_new += x;
-                            is_busy = 1;
                         }
-                    }
+                    };
+                    is_busy = cmd.num_cycles();
                 }
                 _ => {
                     break 'outer;
                 }
             };
-        } else {
-            is_busy -= 1;
         }
+        is_busy -= 1;
 
         let pixel = (cycle - 1) % LINE_WIDTH;
         let is_lit = pixel.abs_diff(v as usize) <= SPRITE_WIDTH_HALF;