LibMarkdown: Implement introspection of the document tree

Author: https://github.com/BenWiederhake
Commit: 24e7196158
Pull-request: https://github.com/SerenityOS/serenity/pull/10420
Reviewed-by: https://github.com/petelliott ✅

Userland/Libraries/LibMarkdown/CodeBlock.cpp

@@ -7,6 +7,7 @@
 #include <AK/StringBuilder.h>
 #include <LibJS/MarkupGenerator.h>
 #include <LibMarkdown/CodeBlock.h>
+#include <LibMarkdown/Visitor.h>
 #include <LibRegex/Regex.h>
 
 namespace Markdown {
@@ -54,6 +55,22 @@ String CodeBlock::render_for_terminal(size_t) const
     return builder.build();
 }
 
+RecursionDecision CodeBlock::walk(Visitor& visitor) const
+{
+    RecursionDecision rd = visitor.visit(*this);
+    if (rd != RecursionDecision::Recurse)
+        return rd;
+
+    rd = visitor.visit(m_code);
+    if (rd != RecursionDecision::Recurse)
+        return rd;
+
+    // Don't recurse on m_language and m_style.
+
+    // Normalize return value.
+    return RecursionDecision::Continue;
+}
+
 static Regex<ECMA262> style_spec_re("\\s*([\\*_]*)\\s*([^\\*_\\s]*).*");
 
 OwnPtr<CodeBlock> CodeBlock::parse(LineIterator& lines)