add char grid str methods

crates/servicepoint/src/char_grid.rs

@@ -1,4 +1,57 @@
 use crate::PrimitiveGrid;
 
 /// A grid containing UTF-8 characters.
-pub type CharGrid = PrimitiveGrid<char>;
+pub type CharGrid = PrimitiveGrid<char>;
+
+impl CharGrid {
+    /// Copies a column from the grid as a String.
+    ///
+    /// Returns [None] if x is out of bounds.
+    pub fn get_col_str(&self, x: usize) -> Option<String> {
+        Some(String::from_iter(self.get_col(x)?))
+    }
+
+    /// Copies a row from the grid as a String.
+    ///
+    /// Returns [None] if y is out of bounds.
+    pub fn get_row_str(&self, y: usize) -> Option<String> {
+        Some(String::from_iter(self.get_row(y)?))
+    }
+
+    /// Overwrites a row in the grid with a str.
+    ///
+    /// Returns [None] if y is out of bounds or `row` is not of the correct size.
+    pub fn set_row_str(&mut self, y: usize, value: &str) -> Option<()> {
+        self.set_row(y, value.chars().collect::<Vec<_>>().as_ref())
+    }
+
+    /// Overwrites a column in the grid with a str.
+    ///
+    /// Returns [None] if y is out of bounds or `row` is not of the correct size.
+    pub fn set_col_str(&mut self, x: usize, value: &str) -> Option<()> {
+        self.set_col(x, value.chars().collect::<Vec<_>>().as_ref())
+    }
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    #[test]
+    fn col_str() {
+        let mut grid = CharGrid::new(2, 3);
+        assert_eq!(grid.get_col_str(2), None);
+        assert_eq!(grid.get_col_str(1), Some(String::from("\0\0\0")));
+        assert_eq!(grid.set_col_str(1, "abc"), Some(()));
+        assert_eq!(grid.get_col_str(1), Some(String::from("abc")));
+    }
+
+    #[test]
+    fn row_str() {
+        let mut grid = CharGrid::new(2, 3);
+        assert_eq!(grid.get_row_str(3), None);
+        assert_eq!(grid.get_row_str(1), Some(String::from("\0\0")));
+        assert_eq!(grid.set_row_str(1, "abc"), None);
+        assert_eq!(grid.set_row_str(1, "ab"), Some(()));
+        assert_eq!(grid.get_row_str(1), Some(String::from("ab")));
+    }
+}