Add palindrome charm (ordinals#4064)

crates/ordinals/src/charm.rs

@@ -15,17 +15,19 @@ pub enum Charm {
   Vindicated = 10,
   Mythic = 11,
   Burned = 12,
+  Palindrome = 13,
 }
 
 impl Charm {
-  pub const ALL: [Self; 13] = [
+  pub const ALL: [Self; 14] = [
     Self::Coin,
     Self::Uncommon,
     Self::Rare,
     Self::Epic,
     Self::Legendary,
     Self::Mythic,
     Self::Nineball,
+    Self::Palindrome,
     Self::Reinscription,
     Self::Cursed,
     Self::Unbound,
@@ -60,6 +62,7 @@ impl Charm {
       Self::Lost => "🤔",
       Self::Mythic => "🎃",
       Self::Nineball => "\u{39}\u{fe0f}\u{20e3}",
+      Self::Palindrome => "🦋",
       Self::Rare => "🧿",
       Self::Reinscription => "♻️",
       Self::Unbound => "🔓",
@@ -90,6 +93,7 @@ impl Display for Charm {
         Self::Lost => "lost",
         Self::Mythic => "mythic",
         Self::Nineball => "nineball",
+        Self::Palindrome => "palindrome",
         Self::Rare => "rare",
         Self::Reinscription => "reinscription",
         Self::Unbound => "unbound",

crates/ordinals/src/sat.rs

@@ -29,6 +29,18 @@ impl Sat {
     self.n() >= 50 * COIN_VALUE * 9 && self.n() < 50 * COIN_VALUE * 10
   }
 
+  pub fn palindrome(self) -> bool {
+    let mut n = self.0;
+    let mut reversed = 0;
+
+    while n > 0 {
+      reversed = reversed * 10 + n % 10;
+      n /= 10;
+    }
+
+    self.0 == reversed
+  }
+
   pub fn percentile(self) -> String {
     format!("{}%", (self.0 as f64 / Self::LAST.0 as f64) * 100.0)
   }
@@ -97,6 +109,10 @@ impl Sat {
       Charm::Nineball.set(&mut charms);
     }
 
+    if self.palindrome() {
+      Charm::Palindrome.set(&mut charms);
+    }
+
     if self.coin() {
       Charm::Coin.set(&mut charms);
     }
@@ -803,4 +819,18 @@ mod tests {
       "failed to parse sat `foo`: invalid percentile",
     );
   }
+
+  #[test]
+  fn palindrome() {
+    assert!(Sat(0).palindrome());
+    assert!(!Sat(10).palindrome());
+    assert!(Sat(11).palindrome());
+  }
+
+  #[test]
+  fn palindrome_charm() {
+    assert!(Charm::Palindrome.is_set(Sat(0).charms()));
+    assert!(!Charm::Palindrome.is_set(Sat(10).charms()));
+    assert!(Charm::Palindrome.is_set(Sat(11).charms()));
+  }
 }

src/templates/sat.rs

@@ -45,6 +45,7 @@ mod tests {
           <dd>
             <span title=coin>🪙</span>
             <span title=mythic>🎃</span>
+            <span title=palindrome>🦋</span>
           </dd>
         </dl>
         .*