1 files changed, 34 insertions, 8 deletions

diff --git a/searchsummary/src/vespa/searchsummary/docsummary/slime_filler_filter.h b/searchsummary/src/vespa/searchsummary/docsummary/slime_filler_filter.h
index a9f441dc505..8bdc683fbb8 100644
--- a/searchsummary/src/vespa/searchsummary/docsummary/slime_filler_filter.h
+++ b/searchsummary/src/vespa/searchsummary/docsummary/slime_filler_filter.h
@@ -8,28 +8,54 @@
 
 namespace search::docsummary {
 
-/*
+/**
  * Class filtering which fields to render in a struct field.
  */
 class SlimeFillerFilter {
+public:
+    /**
+     * Iterator used to step through the sub fields of a struct field
+     * to find out which parts to render.
+     */
+    class Iterator {
+    private:
+        friend class SlimeFillerFilter;
+        bool _should_render;
+        const SlimeFillerFilter* _next;
+        explicit Iterator(bool should_render_in) noexcept;
+        explicit Iterator(const SlimeFillerFilter* next) noexcept;
+    public:
+        Iterator check_field(vespalib::stringref field_name) const;
+        bool should_render() const noexcept { return _should_render; }
+    };
+
+private:
     vespalib::hash_map<vespalib::string, std::unique_ptr<SlimeFillerFilter>> _filter;
-    std::optional<const SlimeFillerFilter*> get_filter(vespalib::stringref field_name) const;
+    Iterator check_field(vespalib::stringref field_name) const;
+
 public:
     SlimeFillerFilter();
     ~SlimeFillerFilter();
-    /*
-     * If field is blocked by the filter then the return value is not set,
-     * otherwise it is set to the filter for the next level.
-     */
-    static std::optional<const SlimeFillerFilter*> get_filter(const SlimeFillerFilter* filter, vespalib::stringref field_name);
+
+    Iterator begin() const;
+
     bool empty() const;
+
+    /**
+     * Add a field path (e.g 'my_field.my_subfield') that should be rendered.
+     */
     SlimeFillerFilter& add(vespalib::stringref field_path);
 
-    /*
+    /**
      * Called by DocsumFilter::prepareFieldSpec() with each input field name as field_path. First component
      * is assumed to be the same as the output field name.
      */
     static void add_remaining(std::unique_ptr<SlimeFillerFilter>& filter, vespalib::stringref field_path);
+
+    /**
+     * Returns a pass-through filter iterator that renders all parts of a struct field.
+     */
+    static Iterator all();
 };
 
 }