diff --git a/include/error_handling.hpp b/include/error_handling.hpp
index 868e320..fad9af1 100644
--- a/include/error_handling.hpp
+++ b/include/error_handling.hpp
@@ -42,6 +42,14 @@ inline void HandleTypecheckError(const std::string& message,
   exit(1);
 }
 
+inline void HandleRuntimeError(const std::string& message,
+                                 const interpreter::tokens::BaseNode& node) { // TODO: place in code
+  std::cout << "Runtime Error: " << message << " at ";
+  PrintPosition(std::cout, node.start_position, node.end_position);
+  std::cout << ".\n";
+  exit(1);
+}
+
 // ...
 
 } // namespace error_handling
diff --git a/include/execute_visitor.hpp b/include/execute_visitor.hpp
index 1a454a5..d18c4e4 100644
--- a/include/execute_visitor.hpp
+++ b/include/execute_visitor.hpp
@@ -7,6 +7,8 @@
 #include "global_info.hpp"
 #include "interpreter_tree.hpp"
 #include "type_info_contexts.hpp"
+#include "utils.hpp"
+#include "values.hpp"
 #include "visitor.hpp"
 #include "error_handling.hpp"
 
@@ -54,9 +56,9 @@ private:
 
   // Definition parts
 
-  void Visit(FunctionDefinition* node) override;
-  void Visit(TypeDefinition* node) override;
-  void Visit(AnyAnnotatedType* node) override;
+  // // void Visit(FunctionDefinition* node) override;
+  // // void Visit(TypeDefinition* node) override;
+  // // void Visit(AnyAnnotatedType* node) override;
 
   // Flow control -----------------
 
@@ -99,7 +101,7 @@ private:
 
   // Name
 
-  void Visit(PartitionName* node) override;
+  // // void Visit(PartitionName* node) override;
   void Visit(NameExpression* node) override;
   void Visit(TupleName* node) override;
   void Visit(VariantName* node) override;
@@ -126,9 +128,9 @@ private:
 
   // Identifiers, constants, etc. -----------------
 
-  void Visit(ExtendedName* node) override;
+  // // void Visit(ExtendedName* node) override;
 
-  void Visit(std::string* node) override; // std::string
+  // // void Visit(std::string* node) override; // std::string
 
   void Visit(FloatNumberLiteral* node) override;
   void Visit(NumberLiteral* node) override;
@@ -137,10 +139,34 @@ private:
   void Visit(UnitLiteral* node) override;
   void Visit(BoolLiteral* node) override;
 
+  bool HandleCondition(Expression& condition, const BaseNode& base_node);
+
+  template<typename T>
+  T* ExtractValue(utils::IdType value, const BaseNode& base_node) {
+    std::optional<T*> maybe_value_info = context_manager_.GetValue<T>(value);
+    if (!maybe_value_info.has_value()) {
+      error_handling::HandleRuntimeError("Value has value class that is different from exprected one", base_node);
+    }
+    return maybe_value_info.value();
+  }
+
+  template<typename T>
+  T* ExtractInternalValue(utils::IdType value, const BaseNode& base_node) {
+    info::value::InternalValue* value_info = ExtractValue<info::value::InternalValue>(value, base_node);
+    std::optional<T*> maybe_internal_value_info = value_info->GetValue<T>();
+    if (!maybe_internal_value_info.has_value()) {
+      error_handling::HandleRuntimeError("Value has internal value class that is different from exprected one", base_node);
+    }
+    return maybe_internal_value_info.value();
+  }
 private:
   info::GlobalInfo::NamespaceVisitor namespace_visitor_;
   info::TypeInfoContextManager& type_info_context_manager_;
   info::ContextManager& context_manager_;
+
+  utils::IdType current_value_;
+  std::optional<LoopControlExpression> active_loop_control_expression_;
+  std::optional<utils::IdType> return_value_; // TODO: work outside block ??
 };
 
 } // namespace interpreter
diff --git a/include/interpreter_tree.hpp b/include/interpreter_tree.hpp
index 8753808..7cf3dbd 100644
--- a/include/interpreter_tree.hpp
+++ b/include/interpreter_tree.hpp
@@ -499,6 +499,8 @@ struct BinaryOperatorExpression {
   OperatorIdentifier operator_name;
   SubExpression left_expression;
   SubExpression right_expression;
+
+  utils::IdType function_id_;
 };
 
 struct UnaryOperatorExpression {
@@ -506,6 +508,8 @@ struct UnaryOperatorExpression {
 
   OperatorIdentifier operator_name;
   Expression expression;
+
+  utils::IdType function_id_;
 };
 
 struct ReferenceExpression {
@@ -532,6 +536,8 @@ struct FunctionCallExpression {
   ExtendedName name;
   std::vector<std::unique_ptr<TypeExpression>> parameters;
   std::vector<SubExpressionToken> arguments;
+
+  utils::IdType function_id_;
 };
 
 struct TupleExpression {
diff --git a/include/values.hpp b/include/values.hpp
index 10ab0b0..07ace42 100644
--- a/include/values.hpp
+++ b/include/values.hpp
@@ -18,13 +18,20 @@ struct Unit {};
 struct InternalValue {
 public:
   InternalValue() = default;
-  InternalValue(std::variant<double,
-                             long long,
-                             std::string,
-                             char,
-                             bool,
-                             Unit>&& value) : value(std::move(value)) {}
+  explicit InternalValue(std::variant<double,
+                                      long long,
+                                      std::string,
+                                      char,
+                                      bool,
+                                      Unit>&& value) : value(std::move(value)) {}
 
+  template<typename T>
+  std::optional<T*> GetValue() {
+    if (!std::holds_alternative<T>(value)) {
+      return std::nullopt;
+    }
+    return std::get<T>(value);
+  }
 public:
   std::variant<double,
                long long,
@@ -37,20 +44,19 @@ public:
 struct TupleValue {
 public:
   TupleValue() = default;
-  TupleValue(std::unordered_map<std::string, utils::IdType>&& fields) : fields(fields) {}
+  explicit TupleValue(std::vector<std::pair<std::optional<std::string>, utils::IdType>>&& fields) : fields(std::move(fields)) {}
 
 public:
-  std::unordered_map<std::string, utils::IdType> fields;
+  std::vector<std::pair<std::optional<std::string>, utils::IdType>> fields;
 };
 
 struct VariantValue {
 public:
   VariantValue() = default;
-  VariantValue(size_t constructor, TupleValue value)
-    : constructor(constructor), value(value) {}
+  VariantValue(TupleValue value) // TODO: add type & constructor??
+    : value(value) {}
 
 public:
-  size_t constructor;
   TupleValue value;
 };
 
@@ -58,7 +64,7 @@ struct ReferenceToValue {
 public:
   ReferenceToValue() = default;
   ReferenceToValue(const std::vector<utils::ReferenceModifier>& references,
-                  utils::IdType value)
+                   utils::IdType value)
     : references(references), value(value) {}
 
 public:
@@ -70,7 +76,7 @@ struct FunctionValue {
 public:
   FunctionValue() = default;
   FunctionValue(std::variant<interpreter::tokens::FunctionDeclaration*,
-               interpreter::tokens::LambdaFunction*> function)
+                interpreter::tokens::LambdaFunction*> function)
     : function(function) {}
 
 public:
@@ -82,17 +88,19 @@ public:
 struct ArrayValue {
 public:
   ArrayValue() = default;
-  ArrayValue(const std::vector<utils::IdType>& elements)
-    : elements(elements) {}
+  explicit ArrayValue(const std::vector<utils::IdType>& elements,
+                      bool is_constant_size)
+    : elements(elements), is_constant_size(is_constant_size) {}
 
 public:
   std::vector<utils::IdType> elements;
+  bool is_constant_size = false;
 };
 
 struct OptionalValue {
 public:
   OptionalValue() = default;
-  OptionalValue(utils::IdType value) : value(value) {}
+  explicit OptionalValue(utils::IdType value) : value(value) {}
 
 public:
   std::optional<utils::IdType> value;
diff --git a/src/execute_visitor.cpp b/src/execute_visitor.cpp
index 286ed7e..14e3cee 100644
--- a/src/execute_visitor.cpp
+++ b/src/execute_visitor.cpp
@@ -1,5 +1,8 @@
 // for clangd
 #include "../include/execute_visitor.hpp"
+#include <cwchar>
+#include <optional>
+#include <variant>
 
 // TODO
 
@@ -7,7 +10,7 @@ namespace interpreter {
 
 // Sources -----------------
 
-void ExecuteVisitor::Visit(SourceFile* node) {
+void ExecuteVisitor::Visit(SourceFile* node) { // never used ??
   for (auto& statement : node->statements) {
     Visitor::Visit(statement);
   }
@@ -15,97 +18,48 @@ void ExecuteVisitor::Visit(SourceFile* node) {
 
 // Namespaces, partitions -----------------
 
-void ExecuteVisitor::Visit(NamespaceSources* node) {
+void ExecuteVisitor::Visit(NamespaceSources* node) { // never used ??
   for (auto& statement : node->statements) {
     Visitor::Visit(statement);
   }
 }
 
-void ExecuteVisitor::Visit(Namespace* node) {
-  Visit(&node->type);
+void ExecuteVisitor::Visit(Namespace* node) { // never used ??
+  // Visit(&node->type);
   Visit(&node->scope);
 }
 
 // Definitions -----------------
 
-void ExecuteVisitor::Visit(ImportStatement* node) {
-  for (auto& symbol : node->symbols) {
-    Visit(&symbol);
-  }
-}
-
-void ExecuteVisitor::Visit(AliasDefinitionStatement* node) {
-  Visit(&node->type);
-  Visit(node->value.get());
-}
+void ExecuteVisitor::Visit(ImportStatement* node) {} // no value
+void ExecuteVisitor::Visit(AliasDefinitionStatement* node) {} // no value
 
 void ExecuteVisitor::Visit(VariableDefinitionStatement* node) {
   Visitor::Visit(node->name);
   Visitor::Visit(node->value);
 }
 
-void ExecuteVisitor::Visit(FunctionDeclaration* node) {
-  Visit(&node->name);
-  for (auto& parameter : node->parameters) {
-    Visit(parameter.get());
-  }
-  Visit(node->type.get());
-}
+void ExecuteVisitor::Visit(FunctionDeclaration* node) {} // no value
 
 void ExecuteVisitor::Visit(FunctionDefinitionStatement* node) {
-  Visit(node->definition.get());
+  // Visit(node->definition.get());
   Visitor::Visit(node->value);
 }
 
-void ExecuteVisitor::Visit(TypeDefinitionStatement* node) {
-  Visit(node->definition.get());
-  Visitor::Visit(node->value);
-}
+void ExecuteVisitor::Visit(TypeDefinitionStatement* node) {} // no value
+void ExecuteVisitor::Visit(AbstractTypeDefinitionStatement* node) {} // no value
 
-void ExecuteVisitor::Visit(AbstractTypeDefinitionStatement* node) {
-  Visit(node->type.get());
-}
-
-void ExecuteVisitor::Visit(TypeclassDefinitionStatement* node) {
-  Visit(node->definition.get());
-  for (auto& requirement : node->requirements) {
-    Visit(requirement.get());
-  }
-}
+void ExecuteVisitor::Visit(TypeclassDefinitionStatement* node) {} // no value
 
 void ExecuteVisitor::Visit(PartitionStatement* node) {
-  Visit(&node->name);
   Visitor::Visit(node->value);
 }
 
-// Definition parts
-
-void ExecuteVisitor::Visit(FunctionDefinition* node) {
-  Visit(&node->name);
-  for (auto& argument : node->arguments) {
-    Visit(&argument);
-  }
-}
-
-void ExecuteVisitor::Visit(TypeDefinition* node) {
-  Visit(node->type.get());
-  for (auto& parameter : node->parameters) {
-    Visit(parameter.get());
-  }
-}
-
-void ExecuteVisitor::Visit(AnyAnnotatedType* node) {
-  Visit(&node->type);
-  for (auto& typeclass : node->typeclasses) {
-    Visit(typeclass.get());
-  }
-}
-
 // Flow control -----------------
 
 void ExecuteVisitor::Visit(TypeConstructorPatternParameter* node) {
   if (node->name.has_value()) {
-    Visit(&node->name.value());
+    // Visit(&node->name.value());
   }
   Visitor::Visit(node->value);
 }
@@ -145,37 +99,122 @@ void ExecuteVisitor::Visit(Condition* node) {
 }
 
 void ExecuteVisitor::Visit(DoWhileLoop* node) {
-  Visitor::Visit(node->statement);
-  Visitor::Visit(node->condition);
+  std::vector<utils::IdType> result;
+  do {
+    Visitor::Visit(node->statement);
+    if (active_loop_control_expression_.has_value()) {
+      if (active_loop_control_expression_.value() == LoopControlExpression::Break) {
+        active_loop_control_expression_ = std::nullopt;
+        break;
+      }
+      active_loop_control_expression_ = std::nullopt;
+      continue;
+
+    }
+    result.push_back(current_value_);
+  } while(HandleCondition(node->condition, node->base));
+
+  current_value_ = context_manager_.AddValue<info::value::ArrayValue>(
+    info::value::ArrayValue(result, false),
+    utils::ValueType::Tmp);
 }
 
 void ExecuteVisitor::Visit(WhileLoop* node) {
-  Visitor::Visit(node->condition);
-  Visitor::Visit(node->statement);
+  std::vector<utils::IdType> result;
+  while(HandleCondition(node->condition, node->base)) {
+    Visitor::Visit(node->statement);
+    if (active_loop_control_expression_.has_value()) {
+      if (active_loop_control_expression_.value() == LoopControlExpression::Break) {
+        active_loop_control_expression_ = std::nullopt;
+        break;
+      }
+      active_loop_control_expression_ = std::nullopt;
+      continue;
+
+    }
+    result.push_back(current_value_);
+  }
+
+  current_value_ = context_manager_.AddValue<info::value::ArrayValue>(
+    info::value::ArrayValue(result, false),
+    utils::ValueType::Tmp);
 }
 void ExecuteVisitor::Visit(ForLoop* node) {
-  Visitor::Visit(node->variable);
+  std::vector<utils::IdType> result;
+
+  // TODO: extend on different interval types (not only array)
   Visitor::Visit(node->interval);
-  Visitor::Visit(node->statement);
+  info::value::ArrayValue* interval = ExtractValue<info::value::ArrayValue>(current_value_, node->base);
+
+  for (auto& value : interval->elements) {
+    current_value_ = value;
+    Visitor::Visit(node->variable);
+
+    Visitor::Visit(node->statement);
+    if (active_loop_control_expression_.has_value()) {
+      if (active_loop_control_expression_.value() == LoopControlExpression::Break) {
+        active_loop_control_expression_ = std::nullopt;
+        break;
+      }
+      active_loop_control_expression_ = std::nullopt;
+      continue;
+
+    }
+    result.push_back(current_value_);
+  }
+
+  current_value_ = context_manager_.AddValue<info::value::ArrayValue>(
+    info::value::ArrayValue(result, false),
+    utils::ValueType::Tmp);
 }
 
 void ExecuteVisitor::Visit(LoopLoop* node) {
-  Visitor::Visit(node->statement);
+  std::vector<utils::IdType> result;
+  while(true) {
+    Visitor::Visit(node->statement);
+    if (active_loop_control_expression_.has_value()) {
+      if (active_loop_control_expression_.value() == LoopControlExpression::Break) {
+        active_loop_control_expression_ = std::nullopt;
+        break;
+      }
+      active_loop_control_expression_ = std::nullopt;
+      continue;
+
+    }
+    result.push_back(current_value_);
+  }
+
+  current_value_ = context_manager_.AddValue<info::value::ArrayValue>(
+    info::value::ArrayValue(result, false),
+    utils::ValueType::Tmp);
 }
 
 // Statements, expressions, blocks, etc. -----------------
 
 void ExecuteVisitor::Visit(Block* node) {
   for (auto& statement : node->statements) {
+    return_value_ = std::nullopt;
     Visitor::Visit(statement);
+    if (return_value_.has_value()) {
+      current_value_ = return_value_.value();
+      return;
+    }
   }
+  current_value_ = context_manager_.AddValue<info::value::InternalValue>(
+    info::value::InternalValue(info::value::Unit()),
+    utils::ValueType::Tmp);
 }
 
 void ExecuteVisitor::Visit(ScopedStatement* node) {
   Visitor::Visit(node->statement);
 }
 
-void ExecuteVisitor::Visit(LoopControlExpression& node) {} // enum
+void ExecuteVisitor::Visit(LoopControlExpression& node) {
+  active_loop_control_expression_ = node;
+
+  current_value_ = context_manager_.AddValue(info::value::InternalValue(info::value::Unit()),
+                                             utils::ValueType::Tmp); // ??
+}
 
 // Operators
 
@@ -186,17 +225,35 @@ void ExecuteVisitor::Visit(BinaryOperatorExpression* node) {
 }
 
 void ExecuteVisitor::Visit(UnaryOperatorExpression* node) {
-  Visit(&node->operator_name);
+  // Visit(&node->operator_name);
   Visitor::Visit(node->expression);
 }
 
 void ExecuteVisitor::Visit(ReferenceExpression* node) {
+  // TODO: check, that therie is no references to "Tmp"
   Visit(node->expression.get());
+
+  utils::ValueType value_type = context_manager_.GetValueType(current_value_);
+
+  current_value_ = context_manager_.AddValue(
+    info::value::ReferenceToValue(node->references, current_value_),
+    value_type);
 }
 
 void ExecuteVisitor::Visit(AccessExpression* node) {
+  // TODO: extend to other types
   Visit(node->name.get());
+  info::value::ArrayValue* array_value = ExtractValue<info::value::ArrayValue>(current_value_, node->base);
+  utils::ValueType value_type = context_manager_.GetValueType(current_value_);
+
   Visitor::Visit(node->id);
+  long long index = *ExtractInternalValue<long long>(current_value_, node->base); // TODO: size_t
+
+  if (index < 0 || index >= array_value->elements.size()) {
+    error_handling::HandleRuntimeError("Access index out of range", node->base);
+  }
+
+  current_value_ = context_manager_.ToModifiedValue(array_value->elements[index], value_type); // needed ??
 }
 
 // Other Expressions
@@ -212,7 +269,7 @@ void ExecuteVisitor::Visit(FunctionCallExpression* node) {
     }
   }
 
-  Visit(&node->name);
+  // Visit(&node->name);
 
   for (auto& parameter : node->parameters) {
     Visit(parameter.get());
@@ -224,24 +281,37 @@ void ExecuteVisitor::Visit(FunctionCallExpression* node) {
 }
 
 void ExecuteVisitor::Visit(TupleExpression* node) {
+  std::vector<std::pair<std::optional<std::string>, utils::IdType>> fields;
+  fields.reserve(node->expressions.size());
   for (auto& expression : node->expressions) {
     Visitor::Visit(expression);
+    fields.push_back({std::nullopt, current_value_});
   }
+
+  current_value_ = context_manager_.AddValue<info::value::TupleValue>(info::value::TupleValue(std::move(fields)),
+                                                     utils::ValueType::Tmp);
 }
 
-void ExecuteVisitor::Visit(VariantExpression* node) {
+// TODO
+void ExecuteVisitor::Visit(VariantExpression* node) { // ??
   for (auto& expression : node->expressions) {
     Visitor::Visit(expression);
+    info::value::OptionalValue* expression_value = ExtractValue<info::value::OptionalValue>(current_value_, node->base);
+    if (expression_value->value.has_value()) {
+
+      break;
+    }
   }
 }
 
 void ExecuteVisitor::Visit(ReturnExpression* node) {
   Visitor::Visit(node->expression);
+  return_value_ = current_value_;
 }
 
 void ExecuteVisitor::Visit(TypeConstructorParameter* node) {
   if (node->name.has_value()) {
-    Visit(&node->name.value());
+    // Visit(&node->name.value());
   }
   Visitor::Visit(node->value);
 }
@@ -253,14 +323,10 @@ void ExecuteVisitor::Visit(TypeConstructor* node) {
   }
 }
 
+// TODO
 void ExecuteVisitor::Visit(LambdaFunction* node) {
-  for (auto& parameter : node->parameters) {
-    Visit(parameter.get());
-  }
-  for (auto& argument : node->arguments) {
-    Visit(&argument);
-  }
-  Visitor::Visit(node->expression);
+  error_handling::HandleInternalError("Lambda function are not implemented yet",
+                                      "ExecuteVisitor.LambdaFunction");
 }
 
 void ExecuteVisitor::Visit(ArrayExpression* node) {
@@ -271,17 +337,9 @@ void ExecuteVisitor::Visit(ArrayExpression* node) {
 
 // Name
 
-void ExecuteVisitor::Visit(PartitionName* node) {
-  for (auto& path_namespace : node->path) {
-    Visit(&path_namespace);
-  }
-
-  Visit(&node->name);
-}
-
 void ExecuteVisitor::Visit(NameExpression* node) {
   for (auto& name : node->names) {
-    Visit(&name);
+    // Visit(&name);
   }
 }
 
@@ -298,7 +356,7 @@ void ExecuteVisitor::Visit(VariantName* node) {
 }
 
 void ExecuteVisitor::Visit(AnnotatedName* node) {
-  Visit(&node->name);
+  // Visit(&node->name);
   if (node->type.has_value()) {
     Visitor::Visit(node->type.value());
   }
@@ -308,85 +366,68 @@ void ExecuteVisitor::Visit(AnnotatedName* node) {
 
 // Type
 
-void ExecuteVisitor::Visit(FunctionType* node) {
-  for (auto& type : node->types) {
-    Visitor::Visit(type);
-  }
-}
-
-void ExecuteVisitor::Visit(TupleType* node) {
-  if (node->type.has_value()) {
-    Visit(&node->type.value());
-  }
-  for (auto& entity : node->entities) {
-    if (entity.first.has_value()) {
-      Visit(&entity.first.value());
-    }
-    Visit(entity.second.get());
-  }
-}
-
-void ExecuteVisitor::Visit(VariantType* node) {
-  if (node->type.has_value()) {
-    Visit(&node->type.value());
-  }
-  for (auto& constructor : node->constructors) {
-    if (std::holds_alternative<Constructor>(constructor)) {
-      Visit(&std::get<Constructor>(constructor));
-    } else if (std::holds_alternative<std::unique_ptr<TupleType>>(constructor)) {
-      Visit(std::get<std::unique_ptr<TupleType>>(constructor).get());
-    } else {
-      // error
-    }
-  }
-}
-
-void ExecuteVisitor::Visit(TypeExpression* node) {
-  for (auto& type : node->path) {
-    Visit(&type);
-  }
-  Visit(&node->type);
-}
-
-void ExecuteVisitor::Visit(ExtendedScopedAnyType* node) {
-  Visitor::Visit(node->type);
-}
+void ExecuteVisitor::Visit(FunctionType* node) {} // no value
+void ExecuteVisitor::Visit(TupleType* node) {} // no value
+void ExecuteVisitor::Visit(VariantType* node) {} // no value
+void ExecuteVisitor::Visit(TypeExpression* node) {} // no value
+void ExecuteVisitor::Visit(ExtendedScopedAnyType* node) {} // no value
 
 // Typeclass
 
-void ExecuteVisitor::Visit(ParametrizedTypeclass* node) {
-  Visit(&node->typeclass);
-  for (auto& parameter : node->parameters) {
-    Visit(parameter.get());
-  }
-}
+void ExecuteVisitor::Visit(ParametrizedTypeclass* node) {} // no value
 
 // Typeclass & Type -----------------
 
-void ExecuteVisitor::Visit(ParametrizedType* node) {
-  Visit(&node->type);
-  for (auto& parameter : node->parameters) {
-    Visit(parameter.get());
-  }
-}
+void ExecuteVisitor::Visit(ParametrizedType* node) {} // no value
 
 // Identifiers, constants, etc. -----------------
 
-void ExecuteVisitor::Visit(ExtendedName* node) {}
+// void ExecuteVisitor::Visit(ExtendedName* node) {}
 
-void ExecuteVisitor::Visit(std::string* node) {} // std::string
+// void ExecuteVisitor::Visit(std::string* node) {} // std::string
 
-void ExecuteVisitor::Visit(FloatNumberLiteral* node) {}
+void ExecuteVisitor::Visit(FloatNumberLiteral* node) {
+  current_value_ = context_manager_.AddValue<info::value::InternalValue>(
+    info::value::InternalValue(node->value),
+    utils::ValueType::Tmp);
+}
 
-void ExecuteVisitor::Visit(NumberLiteral* node) {}
+void ExecuteVisitor::Visit(NumberLiteral* node) {
+  current_value_ = context_manager_.AddValue<info::value::InternalValue>(
+    info::value::InternalValue(node->value),
+    utils::ValueType::Tmp);
+}
 
-void ExecuteVisitor::Visit(StringLiteral* node) {}
+void ExecuteVisitor::Visit(StringLiteral* node) {
+  current_value_ = context_manager_.AddValue<info::value::InternalValue>(
+    info::value::InternalValue(node->value),
+    utils::ValueType::Tmp);
+}
 
-void ExecuteVisitor::Visit(CharLiteral* node) {}
+void ExecuteVisitor::Visit(CharLiteral* node) {
+  current_value_ = context_manager_.AddValue<info::value::InternalValue>(
+    info::value::InternalValue(node->value),
+    utils::ValueType::Tmp);
+}
 
-void ExecuteVisitor::Visit(UnitLiteral* node) {}
+void ExecuteVisitor::Visit(UnitLiteral* node) {
+  current_value_ = context_manager_.AddValue<info::value::InternalValue>(
+    info::value::InternalValue(info::value::Unit()),
+    utils::ValueType::Tmp);
+}
 
-void ExecuteVisitor::Visit(BoolLiteral* node) {}
+void ExecuteVisitor::Visit(BoolLiteral* node) {
+  current_value_ = context_manager_.AddValue<info::value::InternalValue>(
+    info::value::InternalValue(node->value),
+    utils::ValueType::Tmp);
+}
+
+//
+
+bool ExecuteVisitor::HandleCondition(Expression& node, const BaseNode& base_node) {
+  Visitor::Visit(node);
+  return *ExtractInternalValue<bool>(current_value_, base_node);
+}
 
 } // namespace interpreter
 
diff --git a/src/type_check_visitor.cpp b/src/type_check_visitor.cpp
index a10e86e..0b0bab8 100644
--- a/src/type_check_visitor.cpp
+++ b/src/type_check_visitor.cpp
@@ -541,6 +541,7 @@ void TypeCheckVisitor::Visit(Block* node) {
           error_handling::HandleTypecheckError("Different return types in block", node->base);
         }
       }
+      // returned_type_ = std::nullopt; // not needed
     }
   }
   context_manager_.EnterContext();
@@ -571,27 +572,28 @@ void TypeCheckVisitor::Visit(LoopControlExpression& node) { // enum
 void TypeCheckVisitor::Visit(BinaryOperatorExpression* node) {
   // TODO: Check, that type is not abstract ??
   auto maybe_operator_id = namespace_visitor_.FindFunction(std::nullopt, node->operator_name);
+  const info::definition::Function* operator_info = nullptr;
 
   if (maybe_operator_id.has_value()) {
-    const info::definition::Function& operator_info = namespace_visitor_.GetGlobalInfo()->GetFunctionInfo(maybe_operator_id.value());
+    operator_info = &namespace_visitor_.GetGlobalInfo()->GetFunctionInfo(maybe_operator_id.value());
 
-    if (!operator_info.declaration.has_value()) {
+    if (!operator_info->declaration.has_value()) {
       error_handling::HandleTypecheckError("Operator declaration not found", node->base);
     }
 
-    if (!operator_info.definition.has_value()) { // TODO: builtin, etc.
+    if (!operator_info->definition.has_value()) { // TODO: builtin, etc.
       error_handling::HandleTypecheckError("Operator definition not found", node->base);
     }
 
-    if (operator_info.argument_count != 3) { // 2 + return type
+    if (operator_info->argument_count != 3) { // 2 + return type
       error_handling::HandleTypecheckError("Operator wrong argument count", node->base);
     }
 
-    if (operator_info.declaration->parameters.size() > 0) {
+    if (operator_info->declaration->parameters.size() > 0) {
       error_handling::HandleTypecheckError("Operator with parameters", node->base);
     }
 
-    Visitor::Visit(*operator_info.declaration.value().argument_types[0]);
+    Visitor::Visit(*operator_info->declaration.value().argument_types[0]);
     utils::IdType left_expression_type = current_type_; // TODO: type in context of deduced types
 
     Visitor::Visit(node->left_expression);
@@ -599,82 +601,82 @@ void TypeCheckVisitor::Visit(BinaryOperatorExpression* node) {
       error_handling::HandleTypecheckError("Operator left expression has wrong type", node->base);
     }
 
-    Visitor::Visit(*operator_info.declaration.value().argument_types[1]);
+    Visitor::Visit(*operator_info->declaration.value().argument_types[1]);
     utils::IdType right_expression_type = current_type_; // TODO: type in context of deduced types
 
     Visitor::Visit(node->right_expression);
     if (!context_manager_.AddTypeRequirement(current_type_, right_expression_type)) {
       error_handling::HandleTypecheckError("Operator right expression has wrong type", node->base);
     }
+  } else {
 
-    Visitor::Visit(*operator_info.declaration.value().argument_types.back());
-    return;
+    Visitor::Visit(node->left_expression);
+    auto maybe_left_type = context_manager_.GetType<info::type::DefinedType>(current_type_);
+
+    utils::ValueType left_value_type = context_manager_.GetValueType(current_type_);
+
+    if (!maybe_left_type.has_value()) {
+      error_handling::HandleTypecheckError("Operator not found (type is not DefinedType)", node->base);
+    }
+
+    auto maybe_left_type_info = namespace_visitor_.GetGlobalInfo()->GetTypeInfo<info::definition::AnyType>(maybe_left_type.value()->GetTypeId());
+
+    std::string left_type_name = maybe_left_type_info.value()->type.type;
+
+    auto maybe_const_operator_id = namespace_visitor_.FindMethod(std::nullopt,
+                                                                left_type_name,
+                                                                node->operator_name,
+                                                                utils::IsConstModifier::Const);
+
+    if (left_value_type != utils::ValueType::Const) {
+      maybe_operator_id = namespace_visitor_.FindMethod(std::nullopt,
+                                                        left_type_name,
+                                                        node->operator_name,
+                                                        utils::IsConstModifier::Var);
+    }
+
+    if (!maybe_operator_id.has_value() && !maybe_const_operator_id.has_value()) {
+      error_handling::HandleTypecheckError("Operator not found (method name not found)", node->base);
+    }
+
+    if (maybe_operator_id.has_value() && maybe_const_operator_id.has_value()) {
+      error_handling::HandleTypecheckError("Ambigious operator (const and var method)", node->base);
+    }
+
+    if (!maybe_operator_id.has_value()) {
+      maybe_operator_id = maybe_const_operator_id;
+    }
+
+    operator_info = &namespace_visitor_.GetGlobalInfo()->GetFunctionInfo(maybe_operator_id.value());
+
+    if (!operator_info->declaration.has_value()) {
+      error_handling::HandleTypecheckError("Operator declaration not found", node->base);
+    }
+
+    if (!operator_info->definition.has_value()) { // TODO: builtin, etc.
+      error_handling::HandleTypecheckError("Operator definition not found", node->base);
+    }
+
+    if (operator_info->argument_count != 2) { // argument + return type
+      error_handling::HandleTypecheckError("Operator wrong argument count", node->base);
+    }
+
+    if (operator_info->declaration->parameters.size() > 0) {
+      error_handling::HandleTypecheckError("Operator with parameters", node->base);
+    }
+
+    Visitor::Visit(*operator_info->declaration.value().argument_types[9]);
+    utils::IdType right_expression_type = current_type_; // TODO: type in context of deduced types
+
+    Visitor::Visit(node->right_expression);
+    if (!context_manager_.AddTypeRequirement(current_type_, right_expression_type)) {
+      error_handling::HandleTypecheckError("Operator right expression has wrong type", node->base);
+    }
   }
 
-  Visitor::Visit(node->left_expression);
-  auto maybe_left_type = context_manager_.GetType<info::type::DefinedType>(current_type_);
+  node->function_id_ = maybe_operator_id.value(); // IMPORTANT
 
-  utils::ValueType left_value_type = context_manager_.GetValueType(current_type_);
-
-  if (!maybe_left_type.has_value()) {
-    error_handling::HandleTypecheckError("Operator not found (type is not DefinedType)", node->base);
-  }
-
-  auto maybe_left_type_info = namespace_visitor_.GetGlobalInfo()->GetTypeInfo<info::definition::AnyType>(maybe_left_type.value()->GetTypeId());
-
-  std::string left_type_name = maybe_left_type_info.value()->type.type;
-
-  auto maybe_const_operator_id = namespace_visitor_.FindMethod(std::nullopt,
-                                                               left_type_name,
-                                                               node->operator_name,
-                                                               utils::IsConstModifier::Const);
-
-  if (left_value_type != utils::ValueType::Const) {
-    maybe_operator_id = namespace_visitor_.FindMethod(std::nullopt,
-                                                      left_type_name,
-                                                      node->operator_name,
-                                                      utils::IsConstModifier::Var);
-  }
-
-  if (!maybe_operator_id.has_value() && !maybe_const_operator_id.has_value()) {
-    error_handling::HandleTypecheckError("Operator not found (method name not found)", node->base);
-  }
-
-  if (maybe_operator_id.has_value() && maybe_const_operator_id.has_value()) {
-    error_handling::HandleTypecheckError("Ambigious operator (const and var method)", node->base);
-  }
-
-  if (!maybe_operator_id.has_value()) {
-    maybe_operator_id = maybe_const_operator_id;
-  }
-
-  const info::definition::Function& operator_info = namespace_visitor_.GetGlobalInfo()->GetFunctionInfo(maybe_operator_id.value());
-
-  if (!operator_info.declaration.has_value()) {
-    error_handling::HandleTypecheckError("Operator declaration not found", node->base);
-  }
-
-  if (!operator_info.definition.has_value()) { // TODO: builtin, etc.
-    error_handling::HandleTypecheckError("Operator definition not found", node->base);
-  }
-
-  if (operator_info.argument_count != 2) { // argument + return type
-    error_handling::HandleTypecheckError("Operator wrong argument count", node->base);
-  }
-
-  if (operator_info.declaration->parameters.size() > 0) {
-    error_handling::HandleTypecheckError("Operator with parameters", node->base);
-  }
-
-  Visitor::Visit(*operator_info.declaration.value().argument_types[9]);
-  utils::IdType right_expression_type = current_type_; // TODO: type in context of deduced types
-
-  Visitor::Visit(node->right_expression);
-  if (!context_manager_.AddTypeRequirement(current_type_, right_expression_type)) {
-    error_handling::HandleTypecheckError("Operator right expression has wrong type", node->base);
-  }
-
-  Visitor::Visit(*operator_info.declaration.value().argument_types.back());
+  Visitor::Visit(*operator_info->declaration.value().argument_types.back());
 
   node->base.type_ = current_type_;
 }
@@ -714,6 +716,8 @@ void TypeCheckVisitor::Visit(UnaryOperatorExpression* node) {
     error_handling::HandleTypecheckError("Operator expression has wrong type", node->base);
   }
 
+  node->function_id_ = maybe_operator_id.value(); // IMPORTANT
+
   Visitor::Visit(*operator_info.declaration.value().argument_types.back());
 
   node->base.type_ = current_type_;
@@ -867,6 +871,8 @@ void TypeCheckVisitor::Visit(FunctionCallExpression* node) {
     context_manager_.AddTypeRequirement(current_type_, argument_type);
   }
 
+  node->function_id_ = maybe_function_id.value(); // IMPORTANT
+
   Visitor::Visit(*function_declaration.argument_types.back());
   current_type_ = TypeInContext(current_type_, context);
 }
@@ -899,6 +905,9 @@ void TypeCheckVisitor::Visit(VariantExpression* node) {
   }
 
 
+  current_type_ = context_manager_.AddType(info::type::VariantType(std::nullopt, constructors, -1),
+                                           utils::ValueType::Tmp);
+
   current_type_ = context_manager_.AddType(info::type::VariantType(std::nullopt, constructors, -1),
                                            utils::ValueType::Tmp);