coord stuff

src/repr/board.rs

@@ -89,6 +89,7 @@ impl fmt::Display for Board {
             }
             writeln!(f)?;
         }
+
         // put a line at the bottom of the board too
         writeln!(f, " {}", horiz_sep_line)?;
 
@@ -112,6 +113,7 @@ impl fmt::Debug for Board {
 }
 
 impl Board {
+    /// Width of the board
     pub const BOARD_SIZE: CoordAxis = 8;
 
     /// Area of the board

src/repr/coords.rs

@@ -2,11 +2,11 @@ use super::Board;
 use num::Integer;
 use static_assertions::const_assert;
 
-// PERF! having `Coord` be of type `u8` (instead of usize) increases
+/// PERF! having `Coord` be of type `u8` (instead of usize) increases
-// performance by about 1-2% overall
+/// performance by about 1-2% overall
 pub type CoordAxis = u8;
 
-// using u8 for this results in a ~3-6% perf increase
+/// using u8 for this results in a ~3-6% perf increase
 pub type CoordPairInner = u8;
 
 const_assert!(CoordPairInner::MAX as usize >= Board::BOARD_AREA as usize);
@@ -19,6 +19,10 @@ impl CoordPair {
     pub const fn from_axes(row: CoordAxis, col: CoordAxis) -> Self {
         Self(row * Board::BOARD_SIZE + col)
     }
+
+    fn from_index(&self) -> (CoordAxis, CoordAxis) {
+        self.0.div_mod_floor(&Board::BOARD_SIZE)
+    }
 }
 
 impl std::fmt::Display for CoordPair {
@@ -34,8 +38,10 @@ impl std::fmt::Debug for CoordPair {
     }
 }
 
-fn from_index(index: CoordPair) -> (CoordAxis, CoordAxis) {
+impl From<CoordPair> for (CoordAxis, CoordAxis) {
-    index.0.div_mod_floor(&Board::BOARD_SIZE)
+    fn from(val: CoordPair) -> Self {
+        val.from_index()
+    }
 }
 
 impl From<(CoordAxis, CoordAxis)> for CoordPair {
@@ -44,12 +50,6 @@ impl From<(CoordAxis, CoordAxis)> for CoordPair {
     }
 }
 
-impl From<CoordPair> for (CoordAxis, CoordAxis) {
-    fn from(val: CoordPair) -> Self {
-        from_index(val)
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;