refactor: Extract get_lineno_width method

Author: chengr4

src/renderer/display_list.rs

@@ -72,13 +72,7 @@ impl<'a> fmt::Debug for DisplayList<'a> {
 
 impl<'a> Display for DisplayList<'a> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        let max_lineno = self.get_max_lineno();
-        let lineno_width = match max_lineno {
-            None => 0,
-            Some(_max) if self.anonymized_line_numbers => ANONYMIZED_LINE_NUM.len(),
-            Some(0) => 1,
-            Some(max) => (max as f64).log10().floor() as usize + 1,
-        };
+        let lineno_width = self.get_lineno_width();
 
         let multiline_depth = self.body.iter().fold(0, |max, set| {
             set.display_lines.iter().fold(max, |max2, line| match line {
@@ -152,6 +146,17 @@ impl<'a> DisplayList<'a> {
         });
         max_lineno
     }
+
+    fn get_lineno_width(&self) -> usize {
+        let max_lineno = self.get_max_lineno();
+        let lineno_width = match max_lineno {
+            None => 0,
+            Some(_max) if self.anonymized_line_numbers => ANONYMIZED_LINE_NUM.len(),
+            Some(0) => 1,
+            Some(max) => (max as f64).log10().floor() as usize + 1,
+        };
+        lineno_width
+    }
 }
 
 #[derive(Debug, PartialEq)]