Make grid axes dumb enums

rs/src/ui.rs

@@ -30,30 +30,70 @@ trait GridAxisIO: std::fmt::Display
 where
     Self: GridAxis,
 {
-    const ALL_CHARS: [char; 8];
-    fn parse(c: char) -> Result<Self, ()> {
-        let index = Self::ALL_CHARS.iter().position(|p| p == &c).ok_or(())?;
-        Ok(Self::ALL_VALUES[index].clone())
-    }
+    fn parse(c: char) -> Result<Self, ()>;
 }
 
 impl GridAxisIO for board::Rank {
-    const ALL_CHARS: [char; 8] = ['1', '2', '3', '4', '5', '6', '7', '8'];
+    fn parse(c: char) -> Result<Self, ()> {
+        match c {
+            '1' => Ok(board::Rank::_1),
+            '2' => Ok(board::Rank::_2),
+            '3' => Ok(board::Rank::_3),
+            '4' => Ok(board::Rank::_4),
+            '5' => Ok(board::Rank::_5),
+            '6' => Ok(board::Rank::_6),
+            '7' => Ok(board::Rank::_7),
+            '8' => Ok(board::Rank::_8),
+            _ => Err(()),
+        }
+    }
 }
 
 impl std::fmt::Display for board::Rank {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "{}", Self::ALL_CHARS[self.get_index() as usize])
+        let c = match self {
+            board::Rank::_1 => '1',
+            board::Rank::_2 => '2',
+            board::Rank::_3 => '3',
+            board::Rank::_4 => '4',
+            board::Rank::_5 => '5',
+            board::Rank::_6 => '6',
+            board::Rank::_7 => '7',
+            board::Rank::_8 => '8',
+        };
+        write!(f, "{}", c)
     }
 }
 
 impl GridAxisIO for board::File {
-    const ALL_CHARS: [char; 8] = ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h'];
+    fn parse(c: char) -> Result<Self, ()> {
+        match c {
+            'a' => Ok(board::File::A),
+            'b' => Ok(board::File::B),
+            'c' => Ok(board::File::C),
+            'd' => Ok(board::File::D),
+            'e' => Ok(board::File::E),
+            'f' => Ok(board::File::F),
+            'g' => Ok(board::File::G),
+            'h' => Ok(board::File::H),
+            _ => Err(()),
+        }
+    }
 }
 
 impl std::fmt::Display for board::File {
     fn fmt(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
-        write!(f, "{}", Self::ALL_CHARS[self.get_index() as usize])
+        let c = match self {
+            board::File::A => 'a',
+            board::File::B => 'b',
+            board::File::C => 'c',
+            board::File::D => 'd',
+            board::File::E => 'e',
+            board::File::F => 'f',
+            board::File::G => 'g',
+            board::File::H => 'h',
+        };
+        write!(f, "{}", c)
     }
 }