Honor the odd startup setting from org-mode files.

src/compare/diff.rs

@@ -490,11 +490,11 @@ fn compare_heading<'s>(
     let level = get_property(emacs, ":level")?
         .ok_or("Level should not be nil")?
         .as_atom()?;
-    if rust.stars.to_string() != level {
+    if rust.level.to_string() != level {
         this_status = DiffStatus::Bad;
         message = Some(format!(
             "Headline level do not match (emacs != rust): {} != {}",
-            level, rust.stars
+            level, rust.level
         ))
     }
 

src/parser/headline.rs

@@ -1,4 +1,5 @@
 use nom::branch::alt;
+use nom::bytes::complete::is_a;
 use nom::bytes::complete::tag;
 use nom::character::complete::anychar;
 use nom::character::complete::space0;
@@ -11,7 +12,6 @@ use nom::combinator::recognize;
 use nom::combinator::verify;
 use nom::multi::many0;
 use nom::multi::many1;
-use nom::multi::many1_count;
 use nom::multi::separated_list1;
 use nom::sequence::tuple;
 
@@ -39,27 +39,27 @@ use crate::types::PriorityCookie;
 use crate::types::TodoKeywordType;
 
 pub(crate) const fn heading(
-    parent_stars: usize,
+    parent_level: usize,
 ) -> impl for<'b, 'g, 'r, 's> Fn(
     RefContext<'b, 'g, 'r, 's>,
     OrgSource<'s>,
 ) -> Res<OrgSource<'s>, Heading<'s>> {
-    move |context, input: OrgSource<'_>| _heading(context, input, parent_stars)
+    move |context, input: OrgSource<'_>| _heading(context, input, parent_level)
 }
 
 #[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
 fn _heading<'b, 'g, 'r, 's>(
     context: RefContext<'b, 'g, 'r, 's>,
     input: OrgSource<'s>,
-    parent_stars: usize,
+    parent_level: usize,
 ) -> Res<OrgSource<'s>, Heading<'s>> {
     not(|i| context.check_exit_matcher(i))(input)?;
     let (
         remaining,
-        (star_count, maybe_todo_keyword, maybe_priority, maybe_comment, title, heading_tags),
-    ) = headline(context, input, parent_stars)?;
+        (headline_level, maybe_todo_keyword, maybe_priority, maybe_comment, title, heading_tags),
+    ) = headline(context, input, parent_level)?;
     let section_matcher = parser_with_context!(section)(context);
-    let heading_matcher = parser_with_context!(heading(star_count))(context);
+    let heading_matcher = parser_with_context!(heading(headline_level))(context);
     let (remaining, maybe_section) =
         opt(map(section_matcher, DocumentElement::Section))(remaining)?;
     let (remaining, _ws) = opt(tuple((start_of_line, many0(blank_line))))(remaining)?;
@@ -82,7 +82,7 @@ fn _heading<'b, 'g, 'r, 's>(
         remaining,
         Heading {
             source: source.into(),
-            stars: star_count,
+            level: headline_level,
             todo_keyword: maybe_todo_keyword.map(|(todo_keyword_type, todo_keyword)| {
                 (todo_keyword_type, Into::<&str>::into(todo_keyword))
             }),
@@ -106,7 +106,7 @@ pub(crate) fn detect_headline<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, ()
 fn headline<'b, 'g, 'r, 's>(
     context: RefContext<'b, 'g, 'r, 's>,
     input: OrgSource<'s>,
-    parent_stars: usize,
+    parent_level: usize,
 ) -> Res<
     OrgSource<'s>,
     (
@@ -124,11 +124,12 @@ fn headline<'b, 'g, 'r, 's>(
     });
     let parser_context = context.with_additional_node(&parser_context);
 
-    let (remaining, (_, star_count, _)) = tuple((
+    let (remaining, (_, (star_count, _), _)) = tuple((
         start_of_line,
-        verify(many1_count(tag("*")), |star_count| {
-            *star_count > parent_stars
-        }),
+        verify(
+            parser_with_context!(headline_level)(&parser_context),
+            |(level, _)| *level > parent_level,
+        ),
         peek(org_space),
     ))(input)?;
 
@@ -255,3 +256,23 @@ fn priority_cookie<'s>(input: OrgSource<'s>) -> Res<OrgSource<'s>, PriorityCooki
     })?;
     Ok((remaining, cookie))
 }
+
+#[cfg_attr(feature = "tracing", tracing::instrument(ret, level = "debug"))]
+fn headline_level<'b, 'g, 'r, 's>(
+    context: RefContext<'b, 'g, 'r, 's>,
+    input: OrgSource<'s>,
+) -> Res<OrgSource<'s>, (usize, OrgSource<'s>)> {
+    let (remaining, stars) = is_a("*")(input)?;
+    let count = stars.len();
+    let level = match context.get_global_settings().odd_levels_only {
+        crate::context::HeadlineLevelFilter::Odd => {
+            if count % 2 == 0 {
+                (count + 2) / 2
+            } else {
+                (count + 1) / 2
+            }
+        }
+        crate::context::HeadlineLevelFilter::OddEven => count,
+    };
+    Ok((remaining, (level, stars)))
+}

src/parser/in_buffer_settings.rs

@@ -81,6 +81,9 @@ pub(crate) fn apply_in_buffer_settings<'g, 's, 'sf>(
         if settings.contains(&"odd") {
             new_settings.odd_levels_only = HeadlineLevelFilter::Odd;
         }
+        if settings.contains(&"oddeven") {
+            new_settings.odd_levels_only = HeadlineLevelFilter::OddEven;
+        }
     }
 
     Ok(new_settings)

src/types/document.rs

@@ -14,7 +14,7 @@ pub struct Document<'s> {
 #[derive(Debug)]
 pub struct Heading<'s> {
     pub source: &'s str,
-    pub stars: usize,
+    pub level: usize,
     pub todo_keyword: Option<(TodoKeywordType, &'s str)>,
     pub priority_cookie: Option<PriorityCookie>,
     pub title: Vec<Object<'s>>,