Use ranges properly

src/board.rs

@@ -66,7 +66,7 @@ impl Board {
     pub fn update_square(&mut self, point: &Point, value: CellValue) {
         let row_bounds = point.row_bounds();
         let col_bounds = point.col_bounds();
-        for c in self.cells.slice_mut(s![row_bounds.0..row_bounds.1, col_bounds.0..col_bounds.1]) {
+        for c in self.cells.slice_mut(s![row_bounds, col_bounds]) {
             c.remove_candidate(value);
         }
     }
@@ -83,6 +83,12 @@ impl Board {
         0..REGION_SIZE
     }
     
+    pub fn square_iter(&self, point: &Point) -> ndarray::ArrayBase<ViewRepr<&Cell>, Dim<[usize; 2]>> {
+        let row_bounds = point.row_bounds();
+        let col_bounds = point.col_bounds();
+        self.cells.slice(s![row_bounds, col_bounds])
+    }
+
     pub fn row_iter(&self, row: usize) -> ndarray::ArrayBase<ViewRepr<&Cell>, Dim<[usize; 1]>> {
         self.cells.slice(s![row, ..])
     }
@@ -109,17 +115,17 @@ impl Point {
         [self.row, self.col]
     }
     
-    fn _bounds(val: usize) -> (usize, usize) {
+    fn _bounds(val: usize) -> std::ops::Range<usize> {
         let mut start = val / (SUB_REGION_SIZE as usize);
         start *= SUB_REGION_SIZE;
-        (start, start + SUB_REGION_SIZE)
+        std::ops::Range {start, end: start + SUB_REGION_SIZE}
     }
 
-    fn row_bounds(&self) -> (usize, usize) {
+    fn row_bounds(&self) -> std::ops::Range<usize> {
         Self::_bounds(self.row)
     }
     
-    fn col_bounds(&self) -> (usize, usize) {
+    fn col_bounds(&self) -> std::ops::Range<usize> {
         Self::_bounds(self.col)
     }
 }
@@ -133,14 +139,14 @@ mod test {
     #[test]
     fn bounds_are_correct() {
         let origin = Point{ row: 0, col: 0};
-        assert_eq!(origin.row_bounds(), (0, 3));
+        assert_eq!(origin.row_bounds(), 0..3);
-        assert_eq!(origin.col_bounds(), (0, 3));
+        assert_eq!(origin.col_bounds(), 0..3);
         let one = Point{ row: 1, col: 1};
-        assert_eq!(one.row_bounds(), (0, 3));
+        assert_eq!(one.row_bounds(), 0..3);
-        assert_eq!(one.col_bounds(), (0, 3));
+        assert_eq!(one.col_bounds(), 0..3);
         let five = Point{ row: 5, col: 7};
-        assert_eq!(five.row_bounds(), (3, 6));
+        assert_eq!(five.row_bounds(), 3..6);
-        assert_eq!(five.col_bounds(), (6, 9));
+        assert_eq!(five.col_bounds(), 6..9);
     }
 
     #[test]

src/display/cell.rs

@@ -17,9 +17,15 @@ pub fn widget(cell: &Cell) -> iced::Element<Message> {
 
     button(text(display))
         .style(|theme: &Theme, status| {
+            // Get the current theme's palette
             let palette = theme.palette();
+            
+            // Create a default border, since we need to set off the cells
+            // TODO: Figure out how to get this out of the theme?
             let mut border = Border::default().color(LIGHT_GRAY);
             border.width = 1.0;
+            
+            // Return a style based on the status
             match status {
                 button::Status::Active => {
                     button::Style{