Add conversions between srs::PieceType and char,str

mino/src/srs.rs

@@ -45,6 +45,76 @@ impl Spawn for PieceType {
     }
 }
 
+impl PieceType {
+    /// Returns the name of the piece as a string.
+    pub fn name(self) -> &'static str {
+        match self {
+            PieceType::I => "I",
+            PieceType::J => "J",
+            PieceType::L => "L",
+            PieceType::O => "O",
+            PieceType::S => "S",
+            PieceType::T => "T",
+            PieceType::Z => "Z",
+        }
+    }
+
+    /// Returns the name of the piece as a [`char`].
+    pub fn as_char(self) -> char {
+        match self {
+            PieceType::I => 'I',
+            PieceType::J => 'J',
+            PieceType::L => 'L',
+            PieceType::O => 'O',
+            PieceType::S => 'S',
+            PieceType::T => 'T',
+            PieceType::Z => 'Z',
+        }
+    }
+}
+
+impl core::fmt::Display for PieceType {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.write_str(self.name())
+    }
+}
+
+/// Error returned when trying to convert an invalid string to a [`PieceType`].
+#[derive(Debug)]
+pub struct InvalidPieceName;
+
+impl TryFrom<char> for PieceType {
+    type Error = InvalidPieceName;
+    fn try_from(ch: char) -> Result<PieceType, InvalidPieceName> {
+        match ch {
+            'I' => Ok(PieceType::I),
+            'J' => Ok(PieceType::J),
+            'L' => Ok(PieceType::L),
+            'O' => Ok(PieceType::O),
+            'S' => Ok(PieceType::S),
+            'T' => Ok(PieceType::T),
+            'Z' => Ok(PieceType::Z),
+            _ => Err(InvalidPieceName),
+        }
+    }
+}
+
+impl core::str::FromStr for PieceType {
+    type Err = InvalidPieceName;
+    fn from_str(s: &str) -> Result<PieceType, InvalidPieceName> {
+        if s.len() != 1 {
+            return Err(InvalidPieceName);
+        }
+        s.chars().next().unwrap().try_into()
+    }
+}
+
+impl core::fmt::Display for InvalidPieceName {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "invalid piece name")
+    }
+}
+
 pub type Piece = crate::piece::Piece<PieceType>;
 
 #[cfg(test)]
@@ -66,6 +136,14 @@ mod test {
         }
     }
 
+    #[test]
+    fn test_piece_name_parse() {
+        for ty in [L, O, J, I, S, T, Z] {
+            assert_eq!(PieceType::try_from(ty.as_char()).unwrap(), ty);
+            assert_eq!(ty.name().parse::<PieceType>().unwrap(), ty);
+        }
+    }
+
     fn get_cells(ty: PieceType, r: Rot) -> (Range<i16>, Range<i16>, Vec<(i16, i16)>) {
         let loc = Loc { x: 0, y: 0, r };
         let piece = Piece { ty, loc };