More parsing

src/dance_info.rs

@@ -1,3 +1,5 @@
+use std::fmt;
+
 #[derive(serde::Deserialize, Debug, PartialEq, Eq)]
 pub enum DanceRole {
     Leader,
@@ -43,7 +45,7 @@ impl TryFrom<&str> for DanceRole {
     }
 }
 
-#[derive(serde::Deserialize, Debug, PartialEq, Eq)]
+#[derive(serde::Deserialize, Debug, PartialEq, Eq, PartialOrd, Ord)]
 pub enum DanceRank {
     Newcomer,
     Novice,
@@ -68,6 +70,33 @@ impl DanceRank {
     }
 }
 
+#[derive(Debug)]
+pub struct ParseDanceRankError;
+
+impl fmt::Display for ParseDanceRankError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        write!(f, "failed to parse DanceRank")
+    }
+}
+
+impl std::error::Error for ParseDanceRankError {}
+
+impl std::str::FromStr for DanceRank {
+    type Err = ParseDanceRankError;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s {
+            "Newcomer" => Ok(Self::Newcomer),
+            "Novice" => Ok(Self::Novice),
+            "Intermediate" => Ok(Self::Intermediate),
+            "Advanced" => Ok(Self::Advanced),
+            "All-Stars" => Ok(Self::AllStars),
+            "Champions" => Ok(Self::Champions),
+            _ => Err(ParseDanceRankError),
+        }
+    }
+}
+
 #[derive(Debug)]
 pub struct CompState {
     pub rank: DanceRank,