LibMarkdown: Implement introspection of the document tree

Userland/Libraries/LibMarkdown/Table.cpp

@@ -7,6 +7,7 @@
 #include <AK/Debug.h>
 #include <AK/StringBuilder.h>
 #include <LibMarkdown/Table.h>
+#include <LibMarkdown/Visitor.h>
 
 namespace Markdown {
 
@@ -96,6 +97,21 @@ String Table::render_to_html(bool) const
     return builder.to_string();
 }
 
+RecursionDecision Table::walk(Visitor& visitor) const
+{
+    RecursionDecision rd = visitor.visit(*this);
+    if (rd != RecursionDecision::Recurse)
+        return rd;
+
+    for (auto const& column : m_columns) {
+        rd = column.walk(visitor);
+        if (rd == RecursionDecision::Break)
+            return rd;
+    }
+
+    return RecursionDecision::Continue;
+}
+
 OwnPtr<Table> Table::parse(LineIterator& lines)
 {
     auto peek_it = lines;
@@ -207,4 +223,23 @@ OwnPtr<Table> Table::parse(LineIterator& lines)
     return table;
 }
 
+RecursionDecision Table::Column::walk(Visitor& visitor) const
+{
+    RecursionDecision rd = visitor.visit(*this);
+    if (rd != RecursionDecision::Recurse)
+        return rd;
+
+    rd = header.walk(visitor);
+    if (rd != RecursionDecision::Recurse)
+        return rd;
+
+    for (auto const& row : rows) {
+        rd = row.walk(visitor);
+        if (rd == RecursionDecision::Break)
+            return rd;
+    }
+
+    return RecursionDecision::Continue;
+}
+
 }