From f3a83065dab4be42a365646fb431847024db460c Mon Sep 17 00:00:00 2001
From: Bruno BELANYI <bruno@belanyi.fr>
Date: Mon, 18 Jul 2022 17:27:09 +0200
Subject: [PATCH] Add 'Color::{forward,backward}_direction'

---
 src/board/color.rs | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/src/board/color.rs b/src/board/color.rs
index ada896d..92fb4b5 100644
--- a/src/board/color.rs
+++ b/src/board/color.rs
@@ -1,4 +1,4 @@
-use super::Rank;
+use super::{Direction, Rank};
 
 /// An enum representing the color of a player.
 #[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
@@ -69,6 +69,21 @@ impl Color {
             Self::Black => Rank::Second,
         }
     }
+
+    /// Which way do pawns advance for this color.
+    #[inline(always)]
+    pub fn forward_direction(self) -> Direction {
+        match self {
+            Self::White => Direction::North,
+            Self::Black => Direction::South,
+        }
+    }
+
+    /// Which way do the opponent's pawns advance for this color.
+    #[inline(always)]
+    pub fn backward_direction(self) -> Direction {
+        (!self).forward_direction()
+    }
 }
 
 impl std::ops::Not for Color {