[board] Implement TryFrom on string types for Color and Shape

board/src/piece.rs

@@ -7,6 +7,12 @@ use crate::{
 use std::fmt;
 use std::slice::Iter;
 
+#[derive(Debug, Eq, PartialEq)]
+pub enum TryFromError {
+    InvalidCharacter,
+    ZeroLengthString,
+}
+
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub enum Color {
     White = 0,
@@ -32,6 +38,37 @@ impl Default for Color {
     }
 }
 
+impl TryFrom<char> for Color {
+    type Error = TryFromError;
+
+    fn try_from(value: char) -> Result<Self, Self::Error> {
+        match value {
+            'w' | 'W' => Ok(Color::White),
+            'b' | 'B' => Ok(Color::Black),
+            _ => Err(TryFromError::InvalidCharacter),
+        }
+    }
+}
+
+macro_rules! try_from_string {
+    ($type:ty) => {
+        try_from_string!($type, &str);
+        try_from_string!($type, &String);
+    };
+    ($type:ty, $from_type:ty) => {
+        impl TryFrom<$from_type> for $type {
+            type Error = TryFromError;
+
+            fn try_from(value: $from_type) -> Result<Self, Self::Error> {
+                let first_char = value.chars().nth(0).ok_or(TryFromError::ZeroLengthString)?;
+                Self::try_from(first_char)
+            }
+        }
+    };
+}
+
+try_from_string!(Color);
+
 #[derive(Clone, Copy, Debug, Eq, Hash, PartialEq)]
 pub enum Shape {
     Pawn = 0,
@@ -75,9 +112,6 @@ impl Shape {
     }
 }
 
-#[derive(Debug, Eq, PartialEq)]
-pub struct TryFromError;
-
 impl TryFrom<char> for Shape {
     type Error = TryFromError;
 
@@ -89,19 +123,12 @@ impl TryFrom<char> for Shape {
             'R' | 'r' => Ok(Shape::Rook),
             'Q' | 'q' => Ok(Shape::Queen),
             'K' | 'k' => Ok(Shape::King),
-            _ => Err(TryFromError),
+            _ => Err(TryFromError::InvalidCharacter),
         }
     }
 }
 
-impl TryFrom<&str> for Shape {
-    type Error = TryFromError;
-
-    fn try_from(value: &str) -> Result<Self, Self::Error> {
-        let first_char = value.chars().nth(0).ok_or(TryFromError)?;
-        Shape::try_from(first_char)
-    }
-}
+try_from_string!(Shape);
 
 impl Into<char> for &Shape {
     fn into(self) -> char {