Implement a macro for iterators with multiple fields.

src/iter/ast_node_iter.rs

@@ -3,6 +3,7 @@ use std::marker::PhantomData;
 use super::ast_node::AstNode;
 use super::macros::children_iter;
 use super::macros::empty_iter;
+use super::macros::multi_field_iter;
 use crate::types::Bold;
 use crate::types::Code;
 use crate::types::Document;
@@ -35,6 +36,7 @@ pub enum AstNodeIter<'r, 's> {
     // Elements
     Paragraph(ParagraphIter<'r, 's>),
     PlainList(PlainListIter<'r, 's>),
+    PlainListItem(PlainListItemIter<'r, 's>),
     // GreaterBlock(GreaterBlockIter<'r, 's>),
     // DynamicBlock(DynamicBlockIter<'r, 's>),
     // FootnoteDefinition(FootnoteDefinitionIter<'r, 's>),
@@ -154,6 +156,15 @@ children_iter!(
     PlainListIter,
     std::slice::Iter<'r, PlainListItem<'s>>
 );
+
+multi_field_iter!(
+    PlainListItem<'s>,
+    PlainListItemIter,
+    tag,
+    std::slice::Iter<'r, Object<'s>>,
+    children,
+    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!(