diff --git a/include/definitions.hpp b/include/definitions.hpp
index aa1ffd0..78db090 100644
--- a/include/definitions.hpp
+++ b/include/definitions.hpp
@@ -29,12 +29,12 @@ struct Parameter {
 };
 
 struct AbstractType {
-  enum { Basic, Abstract } modifier;
+  utils::AbstractTypeModifier modifier;
   Parameter type;
 };
 
 struct AliasType {
-  enum {Alias, Type, Let} modifier;
+  utils::AliasModifier modifier;
   std::vector<std::string> parameters;
   TypeUsage value;
   interpreter::tokens::AliasDefinitionStatement* node = nullptr;
@@ -87,17 +87,17 @@ struct Import {
 };
 
 struct Namespace {
-  enum Modifier { Const, Var };
 
   std::unordered_map<std::string, utils::IdType> types;
   std::unordered_map<std::string, utils::IdType> functions;
   std::unordered_map<std::string, utils::IdType> constructors;
   std::unordered_map<std::string, Namespace> namespaces;
-  std::unordered_map<std::string, Namespace> variable_namespaces;
+  std::unordered_map<std::string, Namespace> var_namespaces;
+  std::unordered_map<std::string, Namespace> const_namespaces;
 
   Namespace* parent_namespace = nullptr;
 
-  std::optional<Modifier> modifier; // modifier => variable namespace
+  std::optional<utils::IsConstModifier> modifier; // modifier => variable namespace
   std::string type_name;
 };
 
diff --git a/include/global_info.hpp b/include/global_info.hpp
index 1b669b5..c3cb784 100644
--- a/include/global_info.hpp
+++ b/include/global_info.hpp
@@ -27,7 +27,7 @@ public:
     void AddImport(definition::Import&& import_info, const std::optional<std::string>& name = std::nullopt);
 
     void AddEnterNamespace(const std::string& name,
-                           const std::optional<definition::Namespace::Modifier>& modifier = std::nullopt);
+                           std::optional<utils::IsConstModifier> modifier = std::nullopt);
 
     void EnterNamespace(const std::string& name);
 
@@ -41,15 +41,21 @@ public:
     utils::IdType AddFunctionDefinition(const std::string& name,
                                         definition::FunctionDefinition&& function_definition_info);
 
-    utils::IdType AddType(const std::string& type, definition::Type&& type_info);
+    utils::IdType AddType(const std::string& type,
+                          definition::Type&& type_info,
+                          const interpreter::tokens::BaseNode& base_node);
 
     utils::IdType AddAbstractType(const std::string& abstract_type,
-                                  definition::AbstractType&& abstract_type_info);
+                                  definition::AbstractType&& abstract_type_info,
+                                  const interpreter::tokens::BaseNode& base_node);
 
-    utils::IdType AddTypeclass(const std::string& typeclass, definition::Typeclass&& typeclass_info);
+    utils::IdType AddTypeclass(const std::string& typeclass,
+                               definition::Typeclass&& typeclass_info,
+                               const interpreter::tokens::BaseNode& base_node);
 
     utils::IdType AddConstructor(const std::string& constructor,
-                                 definition::Constructor&& constructor_info);
+                                 definition::Constructor&& constructor_info,
+                                 const interpreter::tokens::BaseNode& base_node);
 
     std::optional<definition::Namespace*> FindNamespace(const std::optional<std::vector<std::string>>& path);
 
@@ -58,7 +64,8 @@ public:
 
     std::optional<utils::IdType> FindMethod(const std::optional<std::vector<std::string>>& path,
                                             const std::string& type,
-                                            const std::string& name);
+                                            const std::string& name,
+                                            utils::IsConstModifier modifier);
 
     std::optional<utils::IdType> FindType(const std::optional<std::vector<std::string>>& path,
                                           const std::string& type);
@@ -92,11 +99,13 @@ public:
                                                 namespace_stack_({&global_info.global_namespace_}) {}
 
     template<typename T>
-    std::optional<T> FindSomething(const std::optional<std::vector<std::string>>& path,
-                                    std::function<std::optional<T>(definition::Namespace*)> search_func);
+    std::optional<T> FindSomething(
+      const std::optional<std::vector<std::string>>& path,
+      std::function<std::optional<T>(definition::Namespace*)> search_func);
 
-    std::optional<definition::Namespace*> FindNamespaceIn(definition::Namespace* current_namespace,
-                                                  const std::vector<std::string>& path);
+    std::optional<definition::Namespace*> FindNamespaceIn(
+      definition::Namespace* current_namespace,
+      const std::vector<std::string>& path);
   private:
     std::vector<definition::Namespace*> namespace_stack_;
     std::vector<std::string> current_path_;
diff --git a/include/interpreter_tree.hpp b/include/interpreter_tree.hpp
index 72e7180..5a7a13e 100644
--- a/include/interpreter_tree.hpp
+++ b/include/interpreter_tree.hpp
@@ -296,8 +296,7 @@ struct NamespaceSources {
 struct Namespace {
   BaseNode base;
 
-  enum Modifier { Const, Var };
-  std::optional<Modifier> modifier; // modifier => variable namespace
+  std::optional<utils::IsConstModifier> modifier; // modifier => variable namespace
   TypeIdentifier type;
   NamespaceSources scope;
 
@@ -318,7 +317,7 @@ struct ImportStatement {
 struct AliasDefinitionStatement {
   BaseNode base;
 
-  enum {Alias, Type, Let} modifier;
+  utils::AliasModifier modifier;
   TypeIdentifier type;
   std::vector<AbstractTypeIdentifier> parameters;
   std::unique_ptr<TypeExpression> value;
@@ -329,8 +328,8 @@ struct AliasDefinitionStatement {
 struct VariableDefinitionStatement {
   BaseNode base;
 
-  enum { Var, Const } modifier;
-  enum { Move, Assign } assignment_modifier;
+  utils::IsConstModifier modifier;
+  utils::AssignmentModifier assignment_modifier;
   AnyName name;
   SuperExpression value;
 };
@@ -358,7 +357,7 @@ struct FunctionDefinitionStatement {
 struct TypeDefinitionStatement {
   BaseNode base;
 
-  enum { Struct, Class } modifier;
+  utils::ClassModifier modifier;
   std::unique_ptr<TypeDefinition> definition;
   AnyType value;
 
@@ -368,7 +367,7 @@ struct TypeDefinitionStatement {
 struct AbstractTypeDefinitionStatement {
   BaseNode base;
 
-  enum { Basic, Abstract } modifier;
+  utils::AbstractTypeModifier modifier;
   std::unique_ptr<AnnotatedType> type;
 
   utils::IdType type_graph_id_;
@@ -389,7 +388,7 @@ struct TypeclassDefinitionStatement {
 struct FunctionDefinition {
   BaseNode base;
 
-  enum { Operator, Function } modifier;
+  utils::FunctionTypeModifier modifier;
   ExtendedName name;
   std::vector<ExtendedName> arguments;
 };
@@ -514,7 +513,7 @@ struct UnaryOperatorExpression {
 struct ReferenceExpression {
   BaseNode base;
 
-  std::vector<utils::ReferenceType> references;
+  std::vector<utils::ReferenceModifier> references;
   std::unique_ptr<ScopedStatement> expression;
 };
 
@@ -558,9 +557,8 @@ struct ReturnExpression {
 struct TypeConstructorParameter {
   BaseNode base;
 
-  enum AssignmentModifier { Move, Assign };
   std::optional<ExtendedName> name;
-  std::optional<AssignmentModifier> asignment_modifier;
+  std::optional<utils::AssignmentModifier> asignment_modifier;
   SubExpression value;
 };
 
@@ -663,7 +661,7 @@ struct TypeExpression {
 struct ExtendedScopedAnyType {
   BaseNode base;
 
-  std::vector<utils::ReferenceType> references;
+  std::vector<utils::ReferenceModifier> references;
   AnyType type;
 };
 
diff --git a/include/types.hpp b/include/types.hpp
index 445a508..20f3e37 100644
--- a/include/types.hpp
+++ b/include/types.hpp
@@ -19,8 +19,9 @@ class TypeManager;
 class AbstractType { // later will be found in context
 public:
   AbstractType() = default;
-  AbstractType(const std::string& name,
-               const std::vector<utils::IdType>& requirements) : name_(name) {
+  AbstractType(utils::AbstractTypeModifier modifier,
+               const std::string& name,
+               const std::vector<utils::IdType>& requirements) : modifier_(modifier), name_(name) {
     for (auto& typeclass : requirements) {
       requirements_.insert(typeclass);
     }
@@ -31,6 +32,7 @@ public:
   bool operator<(const AbstractType& type) const;
   bool operator>(const AbstractType& type) const;
 private:
+  utils::AbstractTypeModifier modifier_;
   std::string name_;
   std::unordered_set<utils::IdType> requirements_; // TODO: all typeclasses from tree
 };
@@ -135,7 +137,7 @@ private:
 class ReferenceToType {
 public:
   ReferenceToType() = default;
-  ReferenceToType(const std::vector<utils::ReferenceType>& references,
+  ReferenceToType(const std::vector<utils::ReferenceModifier>& references,
                   utils::IdType type,
                   TypeManager* type_manager)
     : references_(references), type_(type), type_manager_(type_manager) {}
@@ -146,7 +148,7 @@ public:
   bool operator>(const ReferenceToType& type) const;
 
 private:
-  std::vector<utils::ReferenceType> references_;
+  std::vector<utils::ReferenceModifier> references_;
   utils::IdType type_;
   TypeManager* type_manager_ = nullptr;
 };
diff --git a/include/utils.hpp b/include/utils.hpp
index de02aed..5c87112 100644
--- a/include/utils.hpp
+++ b/include/utils.hpp
@@ -9,7 +9,13 @@ using std::size_t;
 
 using IdType = size_t;
 
-enum class ReferenceType { Reference = 0, UniqueReference = 1 };
+enum class ReferenceModifier { Reference = 0, UniqueReference = 1 };
+enum class IsConstModifier { Const = 0, Var = 1 };
+enum class ClassModifier { Struct = 0, Class = 1 };
+enum class AssignmentModifier { Assign = 0, Move = 1 };
+enum class AliasModifier { Alias = 0, Type = 1, Let = 2 };
+enum class AbstractTypeModifier { Basic = 0, Abstract = 1 };
+enum class FunctionTypeModifier { Function = 0, Operator = 1 };
 
 template<typename T>
 class Storage {
diff --git a/src/build_visitor.cpp b/src/build_visitor.cpp
index fb0a41b..4d88370 100644
--- a/src/build_visitor.cpp
+++ b/src/build_visitor.cpp
@@ -95,9 +95,9 @@ void BuildVisitor::Visit(Namespace* node) {
   if (child_count > 3) { // "namespace", ["var"/"const",] type, scope
     std::string modifier = parse_node.NthChild(1).GetValue();
     if (modifier == "const") {
-      node->modifier = Namespace::Const;
+      node->modifier = utils::IsConstModifier::Const;
     } else if (modifier == "var") {
-      node->modifier = Namespace::Var;
+      node->modifier = utils::IsConstModifier::Var;
     }
   }
 
@@ -149,11 +149,11 @@ void BuildVisitor::Visit(AliasDefinitionStatement* node) {
 
   std::string modifier = parse_node.NthChild(0).GetValue();
   if (modifier == "alias") {
-    node->modifier = AliasDefinitionStatement::Alias;
+    node->modifier = utils::AliasModifier::Alias;
   } else if (modifier == "type") {
-    node->modifier = AliasDefinitionStatement::Type;
+    node->modifier = utils::AliasModifier::Type;
   } else if (modifier == "let") {
-    node->modifier = AliasDefinitionStatement::Let;
+    node->modifier = utils::AliasModifier::Let;
   }
 
   node->type = parse_node.ChildByFieldName("type").GetValue();
@@ -182,9 +182,9 @@ void BuildVisitor::Visit(VariableDefinitionStatement* node) {
 
   std::string modifier = parse_node.NthChild(0).GetValue();
   if (modifier == "const") {
-    node->modifier = VariableDefinitionStatement::Const;
+    node->modifier = utils::IsConstModifier::Const;
   } else if (modifier == "var") {
-    node->modifier = VariableDefinitionStatement::Var;
+    node->modifier = utils::IsConstModifier::Var;
   }
 
   current_node_ = parse_node.ChildByFieldName("name");
@@ -195,9 +195,9 @@ void BuildVisitor::Visit(VariableDefinitionStatement* node) {
 
   std::string assignment_modifier = parse_node.NthChild(2).GetValue();
   if (assignment_modifier == "=") {
-    node->assignment_modifier = VariableDefinitionStatement::Assign;
+    node->assignment_modifier = utils::AssignmentModifier::Assign;
   } else if (assignment_modifier == "<-") {
-    node->assignment_modifier = VariableDefinitionStatement::Move;
+    node->assignment_modifier = utils::AssignmentModifier::Move;
   }
 
   current_node_ = parse_node;
@@ -252,9 +252,9 @@ void BuildVisitor::Visit(TypeDefinitionStatement* node) {
 
   std::string modifier = parse_node.NthChild(0).GetValue();
   if (modifier == "class") {
-    node->modifier = TypeDefinitionStatement::Class;
+    node->modifier = utils::ClassModifier::Class;
   } else if (modifier == "struct") {
-    node->modifier = TypeDefinitionStatement::Struct;
+    node->modifier = utils::ClassModifier::Struct;
   }
 
   current_node_ = parse_node.ChildByFieldName("definition");
@@ -274,9 +274,9 @@ void BuildVisitor::Visit(AbstractTypeDefinitionStatement* node) {
 
   std::string modifier = parse_node.NthChild(0).GetValue();
   if (modifier == "basic") {
-    node->modifier = AbstractTypeDefinitionStatement::Basic;
+    node->modifier = utils::AbstractTypeModifier::Basic;
   } else if (modifier == "abstract") {
-    node->modifier = AbstractTypeDefinitionStatement::Abstract;
+    node->modifier = utils::AbstractTypeModifier::Abstract;
   }
 
   current_node_ = parse_node.ChildByFieldName("type");
@@ -397,9 +397,9 @@ void BuildVisitor::Visit(FunctionDefinition* node) {
   node->name.name = parse_node.ChildByFieldName("name").GetValue();
 
   if (parse_node.NthChild(0).GetValue() == "(") {
-    node->modifier = FunctionDefinition::Operator;
+    node->modifier = utils::FunctionTypeModifier::Operator;
   } else {
-    node->modifier = FunctionDefinition::Function;
+    node->modifier = utils::FunctionTypeModifier::Function;
   }
 
   size_t child_count = parse_node.NamedChildCount();
@@ -939,9 +939,9 @@ void BuildVisitor::Visit(ReferenceExpression* node) {
     for (size_t i = 0; i + 1 < child_count; ++i) {
       std::string reference = parse_node.NthChild(i).GetValue();
       if (reference == "~") {
-        node->references[i] = utils::ReferenceType::Reference;
+        node->references[i] = utils::ReferenceModifier::Reference;
       } else if (reference == "@") {
-        node->references[i] = utils::ReferenceType::UniqueReference;
+        node->references[i] = utils::ReferenceModifier::UniqueReference;
       }
     }
   }
@@ -1083,9 +1083,9 @@ void BuildVisitor::Visit(TypeConstructorParameter* node) {
 
     std::string assignment_modifier = current_node_.NextSibling().GetValue();
     if (assignment_modifier == "=") {
-      node->asignment_modifier = TypeConstructorParameter::Assign;
+      node->asignment_modifier = utils::AssignmentModifier::Assign;
     } else if (assignment_modifier == "<-") {
-      node->asignment_modifier = TypeConstructorParameter::Move;
+      node->asignment_modifier = utils::AssignmentModifier::Move;
     }
   }
 
@@ -1445,9 +1445,9 @@ void BuildVisitor::Visit(ExtendedScopedAnyType* node) {
     for (size_t i = 0; i + 1 < child_count; ++i) {
       std::string reference = parse_node.NthChild(i).GetValue();
       if (reference == "~") {
-        node->references[i] = utils::ReferenceType::Reference;
+        node->references[i] = utils::ReferenceModifier::Reference;
       } else if (reference == "@") {
-        node->references[i] = utils::ReferenceType::UniqueReference;
+        node->references[i] = utils::ReferenceModifier::UniqueReference;
       }
     }
   }
diff --git a/src/find_symbols_visitor.cpp b/src/find_symbols_visitor.cpp
index 9e3da04..5dab1da 100644
--- a/src/find_symbols_visitor.cpp
+++ b/src/find_symbols_visitor.cpp
@@ -13,19 +13,7 @@ void FindSymbolsVisitor::Visit(Partition* node) {
 }
 
 void FindSymbolsVisitor::Visit(Namespace* node) {
-  std::optional<info::definition::Namespace::Modifier> modifier;
-  if (node->modifier.has_value()) {
-    switch (node->modifier.value()) {
-      case interpreter::Namespace::Var:
-        modifier = info::definition::Namespace::Var;
-        break;
-      case interpreter::Namespace::Const:
-        modifier = info::definition::Namespace::Const;
-        break;
-    }
-  }
-
-  namespace_visitor_.AddEnterNamespace(node->type, modifier);
+  namespace_visitor_.AddEnterNamespace(node->type, node->modifier);
   Visitor::Visit(&node->scope);
   namespace_visitor_.ExitNamespace();
 }
@@ -51,17 +39,7 @@ void FindSymbolsVisitor::Visit(AliasDefinitionStatement* node) {
 
   info::definition::AliasType alias_info;
 
-  switch (node->modifier) {
-    case interpreter::AliasDefinitionStatement::Alias:
-      alias_info.modifier = info::definition::AliasType::Alias;
-      break;
-    case interpreter::AliasDefinitionStatement::Type:
-      alias_info.modifier = info::definition::AliasType::Type;
-      break;
-    case interpreter::AliasDefinitionStatement::Let:
-      alias_info.modifier = info::definition::AliasType::Let;
-      break;
-  }
+  alias_info.modifier = node->modifier;
 
   // TODO: deduce parameter requirements
 
@@ -71,7 +49,7 @@ void FindSymbolsVisitor::Visit(AliasDefinitionStatement* node) {
 
   info.type = std::move(alias_info);
 
-  node->type_id_ = namespace_visitor_.AddType(node->type, std::move(info));
+  node->type_id_ = namespace_visitor_.AddType(node->type, std::move(info), node->base);
 
   is_in_statement_ = false;
 }
@@ -150,7 +128,7 @@ void FindSymbolsVisitor::Visit(TypeDefinitionStatement* node) {
 
   info.type = std::move(any_type_info);
 
-  node->type_id_ = namespace_visitor_.AddType(type, std::move(info));
+  node->type_id_ = namespace_visitor_.AddType(type, std::move(info), node->base);
 
   is_in_statement_ = false;
 }
@@ -164,18 +142,11 @@ void FindSymbolsVisitor::Visit(AbstractTypeDefinitionStatement* node) {
   info.type = std::move(std::any_cast<info::definition::Parameter>(current_info_));
   current_info_.reset();
 
-  switch (node->modifier) {
-    case interpreter::AbstractTypeDefinitionStatement::Basic:
-      info.modifier = info::definition::AbstractType::Basic;
-      break;
-    case interpreter::AbstractTypeDefinitionStatement::Abstract:
-      info.modifier = info::definition::AbstractType::Abstract;
-      break;
-  }
+  info.modifier = node->modifier;
 
   std::string type = info.type.type;
 
-  node->type_id_ = namespace_visitor_.AddAbstractType(type, std::move(info));
+  node->type_id_ = namespace_visitor_.AddAbstractType(type, std::move(info), node->base);
 
   is_in_statement_ = false;
 }
@@ -201,7 +172,7 @@ void FindSymbolsVisitor::Visit(TypeclassDefinitionStatement* node) {
     current_info_.reset();
   }
 
-  node->typeclass_id_ = namespace_visitor_.AddTypeclass(definition->type.get()->type, std::move(info));
+  node->typeclass_id_ = namespace_visitor_.AddTypeclass(definition->type.get()->type, std::move(info), node->base);
 
   is_in_statement_ = false;
 }
diff --git a/src/global_info.cpp b/src/global_info.cpp
index 9fd0e6a..bc29fca 100644
--- a/src/global_info.cpp
+++ b/src/global_info.cpp
@@ -15,10 +15,14 @@ void GlobalInfo::NamespaceVisitor::AddImport(definition::Import&& import_info,
 }
 
 void GlobalInfo::NamespaceVisitor::AddEnterNamespace(const std::string& name,
-                                                     const std::optional<definition::Namespace::Modifier>& modifier) {
+                                                     std::optional<utils::IsConstModifier> modifier) {
   definition::Namespace* namespace_info = nullptr;
   if (modifier.has_value()) {
-    namespace_info = &namespace_stack_.back()->variable_namespaces[name];
+    if (modifier.value() == utils::IsConstModifier::Const) {
+      namespace_info = &namespace_stack_.back()->const_namespaces[name];
+    } else {
+      namespace_info = &namespace_stack_.back()->var_namespaces[name];
+    }
     namespace_stack_.push_back(namespace_info);
 
     namespace_info->modifier = modifier;
@@ -112,7 +116,8 @@ utils::IdType GlobalInfo::NamespaceVisitor::AddFunctionDefinition(const std::str
 // TODO: internal types, etc.
 // TODO: extended constructor names (point separated names)
 utils::IdType GlobalInfo::NamespaceVisitor::AddType(const std::string& type,
-                                                    definition::Type&& type_info) {
+                                                    definition::Type&& type_info,
+                                                    const interpreter::tokens::BaseNode& base_node) {
   size_t id = 0;
 
   auto type_id_iter = namespace_stack_.back()->types.find(type);
@@ -122,8 +127,8 @@ utils::IdType GlobalInfo::NamespaceVisitor::AddType(const std::string& type,
     namespace_stack_.back()->types[type] = id;
     global_info_.types_.push_back(std::move(type_info));
   } else {
-    error_handling::HandleTypecheckError("More then one type with the same name in namespace");
-  }
+    error_handling::HandleTypecheckError("More then one type with the same name in namespace", base_node);
+  } // TODO: typecheck error??
 
   definition::Type& moved_type_info = global_info_.types_.back();
 
@@ -160,7 +165,7 @@ utils::IdType GlobalInfo::NamespaceVisitor::AddType(const std::string& type,
 
         constructor_info.name = constructor_name;
 
-        AddConstructor(constructor_name, std::move(constructor_info));
+        AddConstructor(constructor_name, std::move(constructor_info), base_node);
       }
     }
   }
@@ -170,19 +175,21 @@ utils::IdType GlobalInfo::NamespaceVisitor::AddType(const std::string& type,
 
 // TODO: link abstract type with let definitions
 utils::IdType GlobalInfo::NamespaceVisitor::AddAbstractType(const std::string& abstract_type,
-                                                            definition::AbstractType&& abstract_type_info) {
+                                                            definition::AbstractType&& abstract_type_info,
+                                                            const interpreter::tokens::BaseNode& base_node) {
   if (!FindAbstractType(abstract_type).has_value()) {
     size_t id = global_info_.abstract_types_.size();
     global_info_.name_to_abstract_type_[abstract_type] = id;
     global_info_.abstract_types_.push_back(std::move(abstract_type_info));
   }
 
-  error_handling::HandleTypecheckError("More then one abstract type with the same name in namespace");
+  error_handling::HandleTypecheckError("More then one abstract type with the same name in namespace", base_node);
   return 0;
 }
 
 utils::IdType GlobalInfo::NamespaceVisitor::AddTypeclass(const std::string& typeclass,
-                                                         definition::Typeclass&& typeclass_info) {
+                                                         definition::Typeclass&& typeclass_info,
+                                                         const interpreter::tokens::BaseNode& base_node) {
   if (!FindTypeclass(typeclass).has_value()) {
     size_t id = global_info_.typeclasses_.size();
     global_info_.name_to_typeclass_[typeclass] = id;
@@ -190,12 +197,13 @@ utils::IdType GlobalInfo::NamespaceVisitor::AddTypeclass(const std::string& type
   }
 
 
-  error_handling::HandleTypecheckError("More then one typeclass with the same name in namespace");
+  error_handling::HandleTypecheckError("More then one typeclass with the same name in namespace", base_node);
   return 0;
 }
 
 utils::IdType GlobalInfo::NamespaceVisitor::AddConstructor(const std::string& constructor,
-                                                           definition::Constructor&& constructor_info) {
+                                                           definition::Constructor&& constructor_info,
+                                                           const interpreter::tokens::BaseNode& base_node) {
   auto constructor_id_iter = namespace_stack_.back()->constructors.find(constructor);
 
   if (constructor_id_iter == namespace_stack_.back()->constructors.end()) {
@@ -204,7 +212,7 @@ utils::IdType GlobalInfo::NamespaceVisitor::AddConstructor(const std::string& co
     global_info_.constructors_.push_back(std::move(constructor_info));
   }
 
-  error_handling::HandleTypecheckError("More then one constructor with the same name in namespace");
+  error_handling::HandleTypecheckError("More then one constructor with the same name in namespace", base_node);
   return 0;
 }
 
@@ -233,14 +241,22 @@ std::optional<utils::IdType> GlobalInfo::NamespaceVisitor::FindFunction(
 std::optional<utils::IdType> GlobalInfo::NamespaceVisitor::FindMethod(
     const std::optional<std::vector<std::string>>& path,
     const std::string& type,
-    const std::string& name) {
+    const std::string& name,
+    utils::IsConstModifier modifier) {
   // TODO: remove overhead
 
   return GlobalInfo::NamespaceVisitor::FindSomething<utils::IdType>(path,
-      [type, name] (definition::Namespace* current_namespace) -> std::optional<utils::IdType> {
+      [type, name, modifier] (definition::Namespace* current_namespace) -> std::optional<utils::IdType> {
 
-    auto variable_namespace_iter = current_namespace->variable_namespaces.find(type);
-    if (variable_namespace_iter == current_namespace->variable_namespaces.end()) {
+
+    auto variable_namespace_iter =
+      (modifier == utils::IsConstModifier::Const
+        ? current_namespace->const_namespaces.find(type)
+        : current_namespace->var_namespaces.find(type));
+    if (variable_namespace_iter ==
+      (modifier == utils::IsConstModifier::Const
+        ? current_namespace->const_namespaces.end()
+        : current_namespace->var_namespaces.end())) {
       return std::nullopt;
     }
 
diff --git a/src/type_check_visitor.cpp b/src/type_check_visitor.cpp
index b9870a9..dd55f59 100644
--- a/src/type_check_visitor.cpp
+++ b/src/type_check_visitor.cpp
@@ -41,31 +41,40 @@ void TypeCheckVisitor::Visit(NamespaceSources* node) {
   current_type_ = context_manager_.AddType(info::type::InternalType::Unit);
 }
 
-void TypeCheckVisitor::Visit(Namespace* node) {
+void TypeCheckVisitor::Visit(Namespace* node) { // TODO: two var namespces for class: const and var
   if (node->modifier.has_value()) {
-    // TODO
-    if (node->link_typeclass_id_.has_value()) {
+    bool is_const = node->modifier.value() == utils::IsConstModifier::Const;
 
+    if (node->link_typeclass_id_.has_value()) { // TODO: think about typeclass
+
+      std::vector<utils::IdType> requirements {node->link_typeclass_id_.value()};
+      utils::IdType abstract_type = context_manager_.AddType(info::type::AbstractType(utils::AbstractTypeModifier::Abstract, node->type, requirements));
+
+      context_manager_.EnterVariableContext("self",
+                                            abstract_type,
+                                            is_const); // TODO: different name ??
+      context_manager_.DefineLocalAbstractType(node->type, abstract_type);
+    } else if (node->link_type_id_.has_value()) {
+      Visitor::Visit(*namespace_visitor_.GetGlobalInfo()->GetTypeInfo<info::definition::AnyType>(node->link_type_id_.value()).value().value); // handle error?
+
+      context_manager_.EnterVariableContext(
+        "self", // TODO: different name ??
+        context_manager_.AddType(
+          info::type::DefinedType(node->link_type_id_.value(), current_type_, context_manager_.GetTypeManager())),
+        is_const);
     }
-
-    if (node->link_type_id_.has_value()) {
-
-    }
-    // Visit(node->link_type_id_);
-
-    // context_manager_.EnterVariableContext(node->name.value().name,
-    //   context_manager_.AddType(info::type::DefinedType {node->type_id_.value()}));
   } else {
     if (node->link_typeclass_id_.has_value()) { // ??
       error_handling::HandleTypecheckError("Typeclass can't have not variable namespace", node->base);
     }
+    context_manager_.EnterContext();
   }
-
   namespace_visitor_.EnterNamespace(node->type);
 
   Visit(&node->scope);
 
   namespace_visitor_.ExitNamespace();
+  context_manager_.ExitContext();
   current_type_ = context_manager_.AddType(info::type::InternalType::Unit);
 }
 
@@ -81,22 +90,27 @@ void TypeCheckVisitor::Visit(AliasDefinitionStatement* node) {
     return;
   }
 
-  // TODO: parameter requirments
+  context_manager_.EnterContext();
+
   for (auto& parameter : node->parameters) {
-    current_type_ = context_manager_.AddType(info::type::AbstractType(parameter, /*TODO*/{}));
+    current_type_ = context_manager_.AddType(info::type::AbstractType(utils::AbstractTypeModifier::Abstract,
+                                                                      parameter,
+                                                                      /*TODO*/{}));
     context_manager_.DefineLocalAbstractType(parameter, current_type_);
   }
 
   Visit(node->value.get());
+
+  context_manager_.ExitContext();
 }
 
-// TODO: remove variable on move, etc.
+// TODO: remove variable on move
 void TypeCheckVisitor::Visit(VariableDefinitionStatement* node) {
   is_in_statement_ = true;
 
   Visitor::Visit(node->value);
   // current_type from value automatically passed to name definitions
-  is_const_definition_ = (node->assignment_modifier == VariableDefinitionStatement::Const);
+  is_const_definition_ = (node->modifier == utils::IsConstModifier::Const);
   Visitor::Visit(node->name);
   is_const_definition_ = std::nullopt;
 
@@ -109,7 +123,6 @@ void TypeCheckVisitor::Visit(FunctionDeclaration* node) {
   bool was_in_statement = is_in_statement_;
   is_in_statement_ = true;
 
-  // check declaration correctness ??
   current_type_ = context_manager_.AddType(info::type::InternalType::Unit);
 
   if (!was_in_statement) {
@@ -139,21 +152,22 @@ void TypeCheckVisitor::Visit(FunctionDefinitionStatement* node) {
       requirements.push_back(typeclass->typeclass_id_);
     }
     // TODO: add recursive typeclasses from typeclass tree
-    current_type_ = context_manager_.AddType(info::type::AbstractType(parameter.type, requirements)); // TODO: move requirements
+    current_type_ = context_manager_.AddType(info::type::AbstractType(utils::AbstractTypeModifier::Abstract,
+                                                                      parameter.type,
+                                                                      requirements));
     if (!context_manager_.DefineLocalAbstractType(parameter.type, current_type_)) {
-      error_handling::HandleTypecheckError("Can't define function parameter type: type redefinition", node->base);
+      error_handling::HandleTypecheckError("Can't define function parameter type: abstract type redefinition", node->base);
     }
   }
 
-  // Visit(node->definition.get()); // ??
   for (size_t i = 0; i < node->definition->arguments.size(); ++i) {
-    Visitor::Visit(*declaration.argument_types[i]); // TODO: ConstructAnyType
+    Visitor::Visit(*declaration.argument_types[i]);
     if (!context_manager_.DefineVariable(node->definition->arguments[i].name, current_type_, true)) { // TODO: watch to reference
       error_handling::HandleTypecheckError("Can't define function argument variable: name redefinition", node->base);
     }
   }
 
-  Visitor::Visit(*declaration.argument_types.back()); // TODO: ConstructAnyType
+  Visitor::Visit(*declaration.argument_types.back());
   utils::IdType return_type = current_type_;
 
   Visitor::Visit(node->value);
@@ -168,11 +182,9 @@ void TypeCheckVisitor::Visit(FunctionDefinitionStatement* node) {
   is_in_statement_ = false;
 }
 
-// TODO ??
 void TypeCheckVisitor::Visit(TypeDefinitionStatement* node) {
   is_in_statement_ = true;
 
-  // check definition correctness ??
   current_type_ = context_manager_.AddType(info::type::InternalType::Unit);
 
   is_in_statement_ = false;
@@ -181,7 +193,7 @@ void TypeCheckVisitor::Visit(TypeDefinitionStatement* node) {
 void TypeCheckVisitor::Visit(AbstractTypeDefinitionStatement* node) {
   is_in_statement_ = true;
 
-  // TODO: basic types ??
+  // basic types ??
 
   std::vector<utils::IdType> requirements;
   requirements.reserve(node->type->typeclasses.size());
@@ -189,9 +201,10 @@ void TypeCheckVisitor::Visit(AbstractTypeDefinitionStatement* node) {
     requirements.push_back(typeclass->typeclass_id_);
   }
   // TODO: add recursive typeclasses from typeclass tree
-  current_type_ = context_manager_.AddType(info::type::AbstractType(node->type->type, requirements));
+
+  current_type_ = context_manager_.AddType(info::type::AbstractType(node->modifier, node->type->type, requirements));
   if (!context_manager_.DefineLocalAbstractType(node->type->type, current_type_)) {
-    error_handling::HandleTypecheckError("Can't define basic/bastract type: type redefinition", node->base);
+    error_handling::HandleTypecheckError("Can't define basic/bastract type: abstract type redefinition", node->base);
   }
 
   current_type_ = context_manager_.AddType(info::type::InternalType::Unit);