cm: add option for specifying a minimum width of ordered lists

src/cm.rs

@@ -473,16 +473,22 @@ impl<'a, 'o, 'c> CommonMarkFormatter<'a, 'o, 'c> {
             let list_delim = parent.delimiter;
             write!(
                 listmarker,
-                "{}{}{}",
+                "{}{} ",
                 list_number,
                 if list_delim == ListDelimType::Paren {
                     ")"
                 } else {
                     "."
-                },
-                if list_number < 10 { "  " } else { " " }
+                }
             )
             .unwrap();
+            let mut current_len = listmarker.len();
+
+            while current_len < self.options.render.ol_width {
+                write!(listmarker, " ").unwrap();
+                current_len += 1;
+            }
+
             listmarker.len()
         };
 
@@ -498,7 +504,11 @@ impl<'a, 'o, 'c> CommonMarkFormatter<'a, 'o, 'c> {
                 write!(self.prefix, " ").unwrap();
             }
         } else {
-            let new_len = self.prefix.len() - marker_width;
+            let new_len = if self.prefix.len() > marker_width {
+                self.prefix.len() - marker_width
+            } else {
+                0
+            };
             self.prefix.truncate(new_len);
             self.cr();
         }

src/parser/mod.rs

@@ -892,6 +892,23 @@ pub struct RenderOptions {
     ///            "<p><figure><img src=\"https://example.com/image.png\" alt=\"image\" title=\"this is an image\" /><figcaption>this is an image</figcaption></figure></p>\n");
     /// ```
     pub figure_with_caption: bool,
+
+    /// Render ordered list with a minimum marker width.
+    /// Having a width lower than 3 doesn't do anything.
+    ///
+    /// ```rust
+    /// # use comrak::{markdown_to_commonmark, Options};
+    /// let mut options = Options::default();
+    /// let input = "1. Something";
+    ///
+    /// assert_eq!(markdown_to_commonmark(input, &options),
+    ///            "1. Something\n");
+    ///
+    /// options.render.ol_width = 5;
+    /// assert_eq!(markdown_to_commonmark(input, &options),
+    ///            "1.   Something\n");
+    /// ```
+    pub ol_width: usize,
 }
 
 #[non_exhaustive]

src/tests/commonmark.rs

@@ -64,18 +64,18 @@ fn wikilinks(markdown: &str, cm: &str) {
 fn commonmark_relist() {
     commonmark(
         concat!("3. one\n", "5. two\n",),
-        // Note that right now we always include enough room for up to two
-        // digits. TODO: Ideally we determine the maximum digit length before
-        // getting this far.
-        concat!("3.  one\n", "4.  two\n",),
+        // Note that right now we always include enough room for up to an user
+        // defined number of digits. TODO: Ideally we determine the maximum
+        // digit length before getting this far.
+        concat!("3. one\n", "4. two\n",),
         None,
     );
 
     let mut options = Options::default();
     options.extension.tasklist = true;
     commonmark(
         concat!("3. [ ] one\n", "5. [ ] two\n",),
-        concat!("3.  [ ] one\n", "4.  [ ] two\n",),
+        concat!("3. [ ] one\n", "4. [ ] two\n",),
         Some(&options),
     );
 }