diff --git a/source/RobotAPI/libraries/armem/CMakeLists.txt b/source/RobotAPI/libraries/armem/CMakeLists.txt
index c4ad28ab1f6880f59adb4ca7eda5e4e8a8a65007..30525916e26ba1f2568ea9dfceef89f2fded353f 100644
--- a/source/RobotAPI/libraries/armem/CMakeLists.txt
+++ b/source/RobotAPI/libraries/armem/CMakeLists.txt
@@ -40,8 +40,9 @@ set(LIB_FILES
core/workingmemory/EntitySnapshot.cpp
core/workingmemory/Memory.cpp
core/workingmemory/ProviderSegment.cpp
- core/workingmemory/Visitor.cpp
core/workingmemory/ice_conversions.cpp
+ core/workingmemory/visitor/Visitor.cpp
+ core/workingmemory/visitor/FunctionalVisitor.cpp
core/longtermmemory/CoreSegment.cpp
core/longtermmemory/Entity.cpp
@@ -137,8 +138,10 @@ set(LIB_HEADERS
core/workingmemory/EntitySnapshot.h
core/workingmemory/Memory.h
core/workingmemory/ProviderSegment.h
- core/workingmemory/Visitor.h
core/workingmemory/ice_conversions.h
+ core/workingmemory/visitor.h
+ core/workingmemory/visitor/Visitor.h
+ core/workingmemory/visitor/FunctionalVisitor.h
core/longtermmemory/CoreSegment.h
core/longtermmemory/Entity.h
diff --git a/source/RobotAPI/libraries/armem/core/workingmemory/visitor.h b/source/RobotAPI/libraries/armem/core/workingmemory/visitor.h
new file mode 100644
index 0000000000000000000000000000000000000000..815ee1b34908dc5916e7d909e709bc735409f63c
--- /dev/null
+++ b/source/RobotAPI/libraries/armem/core/workingmemory/visitor.h
@@ -0,0 +1,4 @@
+#pragma once
+
+#include "visitor/FunctionalVisitor.h"
+#include "visitor/Visitor.h"
diff --git a/source/RobotAPI/libraries/armem/core/workingmemory/Visitor.cpp b/source/RobotAPI/libraries/armem/core/workingmemory/visitor/FunctionalVisitor.cpp
similarity index 100%
rename from source/RobotAPI/libraries/armem/core/workingmemory/Visitor.cpp
rename to source/RobotAPI/libraries/armem/core/workingmemory/visitor/FunctionalVisitor.cpp
diff --git a/source/RobotAPI/libraries/armem/core/workingmemory/visitor/FunctionalVisitor.h b/source/RobotAPI/libraries/armem/core/workingmemory/visitor/FunctionalVisitor.h
new file mode 100644
index 0000000000000000000000000000000000000000..ba0fd3d6ff3879210b7933c3eea62c6a87762172
--- /dev/null
+++ b/source/RobotAPI/libraries/armem/core/workingmemory/visitor/FunctionalVisitor.h
@@ -0,0 +1,107 @@
+#pragma once
+
+#include <functional>
+
+#include "Visitor.h"
+
+
+namespace armarx::armem::wm
+{
+
+ /**
+ * @brief A `Visitor` which can be parametrized by `std::function`
+ * instead of inheriting and overriding.
+ */
+ class FunctionalVisitor : public Visitor
+ {
+ public:
+
+ FunctionalVisitor();
+ virtual ~FunctionalVisitor() override;
+
+ bool visitEnter(Memory& memory) override
+ {
+ return memoryFn ? memoryFn(memory) : Visitor::visitEnter(memory);
+ }
+ bool visitEnter(CoreSegment& coreSegment) override
+ {
+ return coreSegmentFn ? coreSegmentFn(coreSegment) : Visitor::visitEnter(coreSegment);
+ }
+ bool visitEnter(ProviderSegment& providerSegment) override
+ {
+ return providerSegmentFn ? providerSegmentFn(providerSegment) : Visitor::visitEnter(providerSegment);
+ }
+ bool visitEnter(Entity& entity) override
+ {
+ return entityFn ? entityFn(entity) : Visitor::visitEnter(entity);
+ }
+ bool visitEnter(EntitySnapshot& snapshot) override
+ {
+ return snapshotFn ? snapshotFn(snapshot) : Visitor::visitEnter(snapshot);
+ }
+
+ bool visit(EntityInstance& instance) override
+ {
+ return instanceFn ? instanceFn(instance) : Visitor::visit(instance);
+ }
+
+
+
+ // Const versions
+
+ bool applyTo(const Memory& memory);
+ bool applyTo(const CoreSegment& coreSegment);
+ bool applyTo(const ProviderSegment& providerSegment);
+ bool applyTo(const Entity& entity);
+ bool applyTo(const EntitySnapshot& snapshot);
+ bool applyTo(const EntityInstance& instance);
+
+
+ bool visitEnter(const Memory& memory) override
+ {
+ return memoryFn ? constMemoryFn(memory) : Visitor::visitEnter(memory);
+ }
+ bool visitEnter(const CoreSegment& coreSegment) override
+ {
+ return coreSegmentFn ? constCoreSegmentFn(coreSegment) : Visitor::visitEnter(coreSegment);
+ }
+ bool visitEnter(const ProviderSegment& providerSegment) override
+ {
+ return providerSegmentFn ? constProviderSegmentFn(providerSegment) : Visitor::visitEnter(providerSegment);
+ }
+ bool visitEnter(const Entity& entity) override
+ {
+ return entityFn ? constEntityFn(entity) : Visitor::visitEnter(entity);
+ }
+ bool visitEnter(const EntitySnapshot& snapshot) override
+ {
+ return memoryFn ? constSnapshotFn(snapshot) : Visitor::visitEnter(snapshot);
+ }
+
+ bool visit(const EntityInstance& instance) override
+ {
+ return instanceFn ? constInstanceFn(instance) : Visitor::visit(instance);
+ }
+
+
+ std::function<bool(Memory& memory)> memoryFn;
+ std::function<bool(const Memory& memory)> constMemoryFn;
+
+ std::function<bool(CoreSegment& coreSegment)> coreSegmentFn;
+ std::function<bool(const CoreSegment& coreSegment)> constCoreSegmentFn;
+
+ std::function<bool(ProviderSegment& providerSegment)> providerSegmentFn;
+ std::function<bool(const ProviderSegment& providerSegment)> constProviderSegmentFn;
+
+ std::function<bool(Entity& entity)> entityFn;
+ std::function<bool(const Entity& entity)> constEntityFn;
+
+ std::function<bool(EntitySnapshot& snapshot)> snapshotFn;
+ std::function<bool(const EntitySnapshot& snapshot)> constSnapshotFn;
+
+ std::function<bool(EntityInstance& instance)> instanceFn;
+ std::function<bool(const EntityInstance& instance)> constInstanceFn;
+
+ };
+
+}
diff --git a/source/RobotAPI/libraries/armem/core/workingmemory/visitor/Visitor.cpp b/source/RobotAPI/libraries/armem/core/workingmemory/visitor/Visitor.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..ede63a494a7aff26c54ba1d7149200c91be7d987
--- /dev/null
+++ b/source/RobotAPI/libraries/armem/core/workingmemory/visitor/Visitor.cpp
@@ -0,0 +1,191 @@
+#include "Visitor.h"
+
+#include <ArmarXCore/core/exceptions/local/ExpressionException.h>
+
+#include <RobotAPI/libraries/armem/core/workingmemory/Memory.h>
+#include <RobotAPI/libraries/armem/core/error.h>
+
+
+namespace armarx::armem::wm
+{
+
+ Visitor::Visitor()
+ {
+ }
+
+ Visitor::~Visitor()
+ {
+ }
+
+ bool Visitor::applyTo(Memory& memory)
+ {
+ bool cont = true;
+ visitEnter(memory);
+ for (auto& [_, coreSeg] : memory)
+ {
+ if (!applyTo(coreSeg))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(memory);
+ return cont;
+ }
+
+ bool Visitor::applyTo(CoreSegment& coreSegment)
+ {
+ bool cont = true;
+ visitEnter(coreSegment);
+ for (auto& [_, provSeg] : coreSegment)
+ {
+ if (!applyTo(provSeg))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(coreSegment);
+ return cont;
+ }
+
+ bool Visitor::applyTo(ProviderSegment& providerSegment)
+ {
+ bool cont = true;
+ visitEnter(providerSegment);
+ for (auto& [_, entity] : providerSegment)
+ {
+ if (!applyTo(entity))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(providerSegment);
+ return cont;
+ }
+
+ bool Visitor::applyTo(Entity& entity)
+ {
+ bool cont = true;
+ visitEnter(entity);
+ for (auto& [_, snapshot] : entity)
+ {
+ if (!applyTo(snapshot))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(entity);
+ return cont;
+ }
+
+ bool Visitor::applyTo(EntitySnapshot& snapshot)
+ {
+ bool cont = true;
+ visitEnter(snapshot);
+ for (auto& instance : snapshot)
+ {
+ if (!applyTo(instance))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(snapshot);
+ return cont;
+ }
+
+ bool Visitor::applyTo(EntityInstance& instance)
+ {
+ return visit(instance);
+ }
+
+
+ bool Visitor::applyTo(const Memory& memory)
+ {
+ bool cont = true;
+ visitEnter(memory);
+ for (const auto& [_, coreSeg] : memory)
+ {
+ if (!applyTo(coreSeg))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(memory);
+ return cont;
+ }
+
+ bool Visitor::applyTo(const CoreSegment& coreSegment)
+ {
+ bool cont = true;
+ visitEnter(coreSegment);
+ for (const auto& [_, provSeg] : coreSegment)
+ {
+ if (!applyTo(provSeg))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(coreSegment);
+ return cont;
+ }
+
+ bool Visitor::applyTo(const ProviderSegment& providerSegment)
+ {
+ bool cont = true;
+ visitEnter(providerSegment);
+ for (const auto& [_, entity] : providerSegment)
+ {
+ if (!applyTo(entity))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(providerSegment);
+ return cont;
+ }
+
+ bool Visitor::applyTo(const Entity& entity)
+ {
+ bool cont = true;
+ visitEnter(entity);
+ for (const auto& [_, snapshot] : entity)
+ {
+ if (!applyTo(snapshot))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(entity);
+ return cont;
+ }
+
+ bool Visitor::applyTo(const EntitySnapshot& snapshot)
+ {
+ bool cont = true;
+ visitEnter(snapshot);
+ for (const auto& instance : snapshot)
+ {
+ if (!applyTo(instance))
+ {
+ cont = false;
+ break;
+ }
+ }
+ visitExit(snapshot);
+ return cont;
+ }
+
+ bool Visitor::applyTo(const EntityInstance& instance)
+ {
+ return visit(instance);
+ }
+
+}
diff --git a/source/RobotAPI/libraries/armem/core/workingmemory/Visitor.h b/source/RobotAPI/libraries/armem/core/workingmemory/visitor/Visitor.h
similarity index 98%
rename from source/RobotAPI/libraries/armem/core/workingmemory/Visitor.h
rename to source/RobotAPI/libraries/armem/core/workingmemory/visitor/Visitor.h
index c0a3854a242c030113eeb46409c172563660294a..fa789fcf0b6876ec5d9fa0ff1a3944b4e3bf3fd3 100644
--- a/source/RobotAPI/libraries/armem/core/workingmemory/Visitor.h
+++ b/source/RobotAPI/libraries/armem/core/workingmemory/visitor/Visitor.h
@@ -12,7 +12,7 @@ namespace armarx::armem::wm
/**
- * @brief A visitor for the hierarchical Memory data structure.
+ * @brief A visitor for the hierarchical memory data structure.
*/
class Visitor
{