diff --git a/src/board.rs b/src/board.rs
index 2505e79..4a2396c 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -28,33 +28,15 @@ impl Board {
         let self_copy = self.clone();
         for (index, ref mut square) in self.squares.iter_mut().enumerate() {
             if let Square::Marks(ref mut marks) = square {
-                self_copy
-                    .row_from_index(index)
-                    .filter_map(|sq| match sq {
-                        Square::Value(x) => Some(x),
-                        _ => None,
-                    })
-                    .for_each(|value| {
-                        marks.set(value as usize, false);
-                    });
-                self_copy
-                    .col_from_index(index)
-                    .filter_map(|sq| match sq {
-                        Square::Value(x) => Some(x),
-                        _ => None,
-                    })
-                    .for_each(|value| {
-                        marks.set(value as usize, false);
-                    });
-                self_copy
-                    .box_from_index(index)
-                    .filter_map(|sq| match sq {
-                        Square::Value(x) => Some(x),
-                        _ => None,
-                    })
-                    .for_each(|value| {
-                        marks.set(value as usize, false);
-                    });
+                self_copy.row_from_index(index).values().for_each(|value| {
+                    marks.set(value as usize, false);
+                });
+                self_copy.col_from_index(index).values().for_each(|value| {
+                    marks.set(value as usize, false);
+                });
+                self_copy.box_from_index(index).values().for_each(|value| {
+                    marks.set(value as usize, false);
+                });
             }
         }
     }
diff --git a/src/iterators.rs b/src/iterators.rs
index 234c5a3..1bed6f1 100644
--- a/src/iterators.rs
+++ b/src/iterators.rs
@@ -1,3 +1,5 @@
+use bitmaps::Bitmap;
+
 use crate::square::Square;
 
 fn to_row(squares: &[Square; 81], row: usize) -> [Square; 9] {
@@ -71,6 +73,22 @@ impl SquareIter {
             curr: 0,
         }
     }
+
+    pub fn values(self) -> std::iter::FilterMap<SquareIter, impl FnMut(Square) -> Option<u8>> {
+        self.filter_map(|sq| match sq {
+            Square::Value(v) => Some(v),
+            _ => None,
+        })
+    }
+
+    pub fn marks(
+        self,
+    ) -> std::iter::FilterMap<SquareIter, impl FnMut(Square) -> Option<Bitmap<10>>> {
+        self.filter_map(|sq| match sq {
+            Square::Marks(m) => Some(m),
+            _ => None,
+        })
+    }
 }
 
 impl Iterator for SquareIter {
diff --git a/src/validator.rs b/src/validator.rs
index 7cc8b82..71f8941 100644
--- a/src/validator.rs
+++ b/src/validator.rs
@@ -23,30 +23,21 @@ where
 
 pub fn validate_board(board: &Board) -> BoardState {
     for r in 0..9 {
-        if !are_unique(board.row(r).filter_map(|sq| match sq {
-            Square::Value(x) => Some(x),
-            _ => None,
-        })) {
+        if !are_unique(board.row(r).values()) {
             // TODO: Add the index.
             return BoardState::Broken(0);
         }
     }
 
     for c in 0..9 {
-        if !are_unique(board.col(c).filter_map(|sq| match sq {
-            Square::Value(x) => Some(x),
-            _ => None,
-        })) {
+        if !are_unique(board.col(c).values()) {
             // TODO: Add the index.
             return BoardState::Broken(0);
         }
     }
 
     for b in 0..9 {
-        if !are_unique(board.boxn(b).filter_map(|sq| match sq {
-            Square::Value(x) => Some(x),
-            _ => None,
-        })) {
+        if !are_unique(board.boxn(b).values()) {
             // TODO: Add the index.
             return BoardState::Broken(0);
         }