From db42964a4777b16028d21ef59cd5fe7d814e4d19 Mon Sep 17 00:00:00 2001
From: Simon Gardling <titaniumtown@proton.me>
Date: Wed, 29 Jan 2025 10:30:49 -0500
Subject: [PATCH] cleanup

---
 src/board.rs | 39 +++++++++++++++++++++++----------------
 src/misc.rs  |  6 +++++-
 2 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/src/board.rs b/src/board.rs
index f9c558c..8e468ad 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -64,10 +64,10 @@ impl Board {
     }
 
     pub fn what_if(&self, i: usize, j: usize, piece: Piece) -> Option<(Self, usize)> {
-        let mut self_copy = *self;
-        if self_copy.get(i, j).is_some() {
+        if self.get(i, j).is_some() {
             return None;
         }
+        let mut self_copy = *self;
         self_copy.place_unchecked(i, j, piece);
         let how_many_prop = self_copy.propegate_from(i, j);
         if how_many_prop == 0 {
@@ -96,21 +96,29 @@ impl Board {
         };
 
         // Create all chains from the piece being propegated from in `i` and `j` coordinates
-        let mut chains: Vec<Vec<(usize, usize)>> = split_from(0, BOARD_SIZE - 1, i)
+        let (i_chain, j_chain) = (
+            split_from(0, BOARD_SIZE - 1, i),
+            split_from(0, BOARD_SIZE - 1, j),
+        );
+
+        let mut chains: Vec<Vec<(usize, usize)>> = i_chain
+            .clone()
             .into_iter()
             .map(|range| range.into_iter().map(|i| (i, j)).collect())
             .collect();
 
         chains.extend(
-            split_from(0, BOARD_SIZE - 1, j)
+            j_chain
+                .clone()
                 .into_iter()
                 .map(|range| range.into_iter().map(|j| (i, j)).collect()),
         );
 
+        // handle diagonals
         chains.extend(
-            split_from(0, BOARD_SIZE - 1, i)
+            i_chain
                 .into_iter()
-                .zip(split_from(0, BOARD_SIZE - 1, j))
+                .zip(j_chain)
                 .map(|(i_vec, j_vec)| i_vec.into_iter().zip(j_vec).collect()),
         );
 
@@ -119,21 +127,20 @@ impl Board {
         for chain in chains {
             for (chain_length, &(new_i, new_j)) in chain.iter().enumerate() {
                 let Some(piece) = self.get(new_i, new_j) else {
+                    // chain interupted by blank space
                     break;
                 };
 
                 if piece == &starting_color {
-                    if chain_length > 0 {
-                        // fill all opposite colors with this color
-                        let Some(history) = chain.get(..chain_length) else {
-                            break;
-                        };
-                        captured += history.len();
+                    // fill all opposite colors with this color
+                    let Some(history) = chain.get(..chain_length) else {
+                        break;
+                    };
+                    captured += history.len();
 
-                        // fill all opposite colors with this color
-                        for &(i_o, j_o) in history {
-                            self.place_unchecked(i_o, j_o, starting_color);
-                        }
+                    // fill all opposite colors with this color
+                    for &(i_o, j_o) in history {
+                        self.place_unchecked(i_o, j_o, starting_color);
                     }
                     // either the other pieces were replaced, or this was an invalid chain,
                     // in both cases, the loop needs to be breaked
diff --git a/src/misc.rs b/src/misc.rs
index 5630cd8..cdd8b3b 100644
--- a/src/misc.rs
+++ b/src/misc.rs
@@ -6,6 +6,7 @@ where
     RangeInclusive<T>: Iterator<Item = T> + DoubleEndedIterator,
     Rev<RangeInclusive<T>>: Iterator<Item = T>,
 {
+    // check that x is in range
     if min > x || x > max {
         return Vec::new();
     }
@@ -35,6 +36,9 @@ mod test {
         assert_eq!(split_from(0, 6, 6), vec![vec![5, 4, 3, 2, 1, 0]]);
 
         // test out-of-bounds and also generics
-        assert_eq!(split_from::<i16>(-1, 4, 10), Vec::<Vec<i16>>::new());
+        assert_eq!(
+            split_from::<i16>(-1i16, 4i16, 10i16),
+            Vec::<Vec<i16>>::new()
+        );
     }
 }