@@ 385,14 385,15 @@ impl View for EditorView {
             (self.scrollbase.start_line + self.scrollbase.view_height)
                 .min(self.buf.text().len_lines());
 
-        // Cache the line strings.
-        for line_idx in line_idc.clone() {
-            if let None = self.lines.get(&line_idx) {
-                self.lines.insert(line_idx,
+        // Automatically allocate and cache the line strings.
+        fn get_line<'a, 'b>(line_idx: usize, buf: &'b Buffer, lines: &'a mut BTreeMap<usize, String>) -> &'a str {
+            if let None = lines.get(&line_idx) {
+                lines.insert(line_idx,
                     // allocate owned string
-                    self.buf.text().line(line_idx).to_string()
+                    buf.text().line(line_idx).to_string()
                 );
             }
+            lines.get(&line_idx).unwrap().as_str()
         }
 
         { // Cache the line styles.

          
@@ 406,18 407,15 @@ impl View for EditorView {
                                 .unwrap_or_else(|| (0, self.highlighting.start()));
 
                             for line_idx in start_line_idx..line_idx {
-                                highlight.parse(
-                                    self.lines.get(&line_idx).expect("line not allocated").as_str()
-                                );
+                                highlight.parse(get_line(line_idx, &self.buf, &mut self.lines));
                             }
 
                             highlight
                         });
 
-                    let line = self.lines.get(&line_idx).expect("line not allocated").as_str();
                     self.spans.insert(line_idx,
                         // highlight syntax
-                        highlight.highlight(line)
+                        highlight.highlight(get_line(line_idx, &self.buf, &mut self.lines))
                     );
 
                     current_highlight = Some(highlight);

          
@@ 539,7 537,7 @@ impl View for EditorView {
                     let mut style: Style = ColorStyle::primary().into(); // fallback
                     // find style at span under cursor
                     if let Some(spans) = self.spans.get(&line_idx) {
-                        let line = self.lines.get(&line_idx).expect("line not cached");
+                        let line = get_line(line_idx, &self.buf, &mut self.lines);
 
                         let mut x_acc = 0;
                         for span in spans.iter() {