Implement DocumentIter and SectionIter.

src/iter/ast_node_iter.rs

@@ -5,6 +5,7 @@ use super::macros::children_iter;
 use super::macros::empty_iter;
 use crate::types::Bold;
 use crate::types::Code;
+use crate::types::Document;
 use crate::types::DocumentElement;
 use crate::types::Element;
 use crate::types::Heading;
@@ -13,6 +14,7 @@ use crate::types::Object;
 use crate::types::PlainText;
 use crate::types::RadioLink;
 use crate::types::RegularLink;
+use crate::types::Section;
 use crate::types::StrikeThrough;
 use crate::types::Underline;
 use crate::types::Verbatim;
@@ -24,9 +26,9 @@ use crate::types::Verbatim;
 /// This only iterates over AST nodes, so an AstNodeIter::Heading would iterate over both the title and section contents, but it would not iterate over simple strings like the TODO keyword or priority.
 pub enum AstNodeIter<'r, 's> {
     // Document Nodes
-    // Document(DocumentIter<'r, 's>),
+    Document(DocumentIter<'r, 's>),
     Heading(HeadingIter<'r, 's>),
-    // Section(SectionIter<'r, 's>),
+    Section(SectionIter<'r, 's>),
     // Elements
     // Paragraph(ParagraphIter<'r, 's>),
     // PlainList(PlainListIter<'r, 's>),
@@ -80,6 +82,35 @@ pub enum AstNodeIter<'r, 's> {
     // Timestamp(TimestampIter<'r, 's>),
 }
 
+pub struct DocumentIter<'r, 's> {
+    zeroth_section_next: std::option::Iter<'r, Section<'s>>,
+    children_next: std::slice::Iter<'r, Heading<'s>>,
+}
+
+impl<'r, 's> Iterator for DocumentIter<'r, 's> {
+    type Item = AstNode<'r, 's>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        self.zeroth_section_next
+            .next()
+            .map(Into::<AstNode>::into)
+            .or_else(|| self.children_next.next().map(Into::<AstNode>::into))
+    }
+}
+
+impl<'r, 's> IntoIterator for &'r Document<'s> {
+    type Item = AstNode<'r, 's>;
+
+    type IntoIter = DocumentIter<'r, 's>;
+
+    fn into_iter(self) -> Self::IntoIter {
+        DocumentIter {
+            zeroth_section_next: self.zeroth_section.iter(),
+            children_next: self.children.iter(),
+        }
+    }
+}
+
 pub struct HeadingIter<'r, 's> {
     title_next: std::slice::Iter<'r, Object<'s>>,
     children_next: std::slice::Iter<'r, DocumentElement<'s>>,
@@ -109,6 +140,7 @@ impl<'r, 's> IntoIterator for &'r Heading<'s> {
     }
 }
 
+children_iter!(Section<'s>, SectionIter, std::slice::Iter<'r, Element<'s>>);
 children_iter!(Bold<'s>, BoldIter, std::slice::Iter<'r, Object<'s>>);
 children_iter!(Italic<'s>, ItalicIter, std::slice::Iter<'r, Object<'s>>);
 children_iter!(