day02: Add part 2

I suspect there must be a better way which could present this more
generically e.g. if I could iterate over the enum somehow ...

day02/src/main.rs

@@ -17,9 +17,6 @@ impl Values {
 			"A" => Values::Rock,
 			"B" => Values::Paper,
 			"C" => Values::Scissors,
-			"X" => Values::Rock,
-			"Y" => Values::Paper,
-			"Z" => Values::Scissors,
 			_ => panic!("Unexpected value for Values")
 		}
 	}
@@ -28,23 +25,61 @@ impl Values {
 		match self {
 			Values::Rock => 1,
 			Values::Paper => 2,
-			Values::Scissors => 3
+			Values::Scissors => 3,
 		}
 	}
 
-	fn beats(self, other: Values) -> bool {
-		if self == Values::Rock {
-			other == Values::Scissors
-		} else if self == Values::Paper {
-			other == Values::Rock
-		} else if self == Values::Scissors {
-			other == Values::Paper
-		} else {
-			false
+	fn get_other(&self, play_result: &PlayResult) -> Values {
+		match self {
+			Values::Rock => {
+				match play_result {
+					PlayResult::Lose => Values::Scissors,
+					PlayResult::Draw => Values::Rock,
+					PlayResult::Win => Values::Paper
+				}
+			},
+			Values::Paper => {
+				match play_result {
+					PlayResult::Lose => Values::Rock,
+					PlayResult::Draw => Values::Paper,
+					PlayResult::Win => Values::Scissors
+				}
+			},
+			Values::Scissors => {
+				match play_result {
+					PlayResult::Lose => Values::Paper,
+					PlayResult::Draw => Values::Scissors,
+					PlayResult::Win => Values::Rock,
+				}
+			},
 		}
 	}
 }
 
+enum PlayResult {
+	Lose,
+	Draw,
+	Win,
+}
+
+impl PlayResult {
+	fn get_from_str(v: &str) -> PlayResult {
+		match v {
+			"X" => PlayResult::Lose,
+			"Y" => PlayResult::Draw,
+			"Z" => PlayResult::Win,
+			_ => panic!("Unexpected value for PlayResult")
+		}
+	}
+
+	fn get_u32(&self) -> u32 {
+		match self {
+			PlayResult::Lose => 0,
+			PlayResult::Draw => 3,
+			PlayResult::Win => 6
+		}
+	}
+}
 
 fn main() -> Result<(), Box<dyn error::Error>> {
 	let f = File::open("input.txt")?;
@@ -53,15 +88,13 @@ fn main() -> Result<(), Box<dyn error::Error>> {
 	let mut sum: u32 = 0;
 	for line in reader.lines() {
 		let line = line?;
-		let mut split_result = line.split_whitespace().map(|o| Values::get_from_str(o));
-		let other = split_result.next().unwrap();
-		let my = split_result.next().unwrap();
+		let split_result = line.split_whitespace().collect::<Vec<&str>>();
+		let other = Values::get_from_str(split_result[0]);
+		let play_result = PlayResult::get_from_str(split_result[1]);
+		let my = other.get_other(&play_result);
+
 		sum += my.get_u32();
-		if other == my {
-			sum += 3;
-		} else if my.beats(other) {
-			sum += 6;
-		}
+		sum += play_result.get_u32();
 	}
 
     println!("{}", sum);