diff --git a/include/abstract_types_context.hpp b/include/abstract_types_context.hpp
new file mode 100644
index 0000000..0113185
--- /dev/null
+++ b/include/abstract_types_context.hpp
@@ -0,0 +1,73 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <optional>
+#include <unordered_map>
+
+// for clangd
+#include "utils.hpp"
+
+namespace info {
+
+class AbstractTypesContextManager {
+public:
+  void EnterContext() {
+    contexts_.emplace_back();
+  }
+
+  void ExitContext() {
+    if (contexts_.empty()) {
+      // error
+    }
+
+    contexts_.pop_back();
+  }
+
+  void ExitFromAllContexts() {
+    contexts_.clear();
+  }
+
+  bool DefineType(const std::string& type, utils::IdType id) {
+    return contexts_.back().DefineType(type, id);
+  }
+
+  std::optional<utils::IdType> GetTypeId(const std::string& type) {
+    for (ssize_t i = contexts_.size() - 1; i >= 0; --i) {
+      auto maybe_type = contexts_[i].GetTypeId(type);
+      if (maybe_type.has_value()) {
+        return maybe_type.value();
+      }
+    }
+    return std::nullopt;
+  }
+
+private:
+  class Context {
+  public:
+    bool DefineType(const std::string& type, utils::IdType id) {
+      if (types_.count(type) > 0) {
+        return false;
+      }
+      types_[type] = id;
+      return true;
+    }
+
+    std::optional<utils::IdType> GetTypeId(const std::string& type) {
+      auto type_iter = types_.find(type);
+
+      if (type_iter == types_.end()) {
+        return std::nullopt;
+      }
+
+      return type_iter->second;
+    }
+
+  private:
+    std::unordered_map<std::string, utils::IdType> types_;
+  };
+
+  std::vector<Context> contexts_;
+};
+
+} // namespace info
diff --git a/include/error_handling.hpp b/include/error_handling.hpp
index 3c9d4df..aee85cb 100644
--- a/include/error_handling.hpp
+++ b/include/error_handling.hpp
@@ -1,29 +1,24 @@
+#pragma once
+
 #include <iostream>
 
-enum class ErrorVisitor {
-  BuildVisitor,
-  PrintVisitor,
-  FindSymbolsVisitor,
-  // ...
-};
+namespace error_handling {
 
-// TODO
-inline void handle_error(std::string message, ErrorVisitor visitor) { // TODO: add place in code
-  std::string visitor_str;
-  switch (visitor) {
-    case ErrorVisitor::BuildVisitor:
-      visitor_str = "Build Visitor";
-      break;
-    case ErrorVisitor::PrintVisitor:
-      visitor_str = "Print Visitor";
-      break;
-    case ErrorVisitor::FindSymbolsVisitor:
-      visitor_str = "Find Symbols Visitor";
-      break;
-    // ...
-    default:
-      break;
-  }
-  std::cerr << "Error: " << message << " in " << visitor_str;
+inline void HandleParsingError(const std::string& message, std::pair<size_t, size_t> place) {
+  std::cout << "Parsing Error: " << message << " at (" << place.first << ", " << place.second << ").\n";
   exit(1);
 }
+
+inline void HandleInternalError(const std::string& message, const std::string& place) {
+  std::cout << "Internal Error: " << message << " at " << place << ".\n";
+  exit(1);
+}
+
+inline void HandleTypecheckError(const std::string& message) { // TODO: place in code
+  std::cout << "Typecheck Error: " << message << ".\n";
+  exit(1);
+}
+
+// ...
+
+} // namespace error_handling
diff --git a/include/global_info.hpp b/include/global_info.hpp
index 2801d1d..7156427 100644
--- a/include/global_info.hpp
+++ b/include/global_info.hpp
@@ -63,6 +63,10 @@ public:
     TypeGraph* GetAbstractTypeGraph() {
       return global_info_.GetAbstractTypeGraph();
     }
+
+    const std::vector<std::string>& GetCurrentPath() {
+      return current_path_;
+    }
   private:
     NamespaceVisitor(GlobalInfo& global_info) : global_info_(global_info),
                                                 namespace_stack_({&global_info.global_namespace_}) {}
@@ -75,6 +79,7 @@ public:
                                                   const std::vector<std::string>& path);
   private:
     std::vector<NamespaceInfo*> namespace_stack_;
+    std::vector<std::string> current_path_;
 
     GlobalInfo& global_info_;
   };
diff --git a/include/interpreter_tree.hpp b/include/interpreter_tree.hpp
index f89d36b..dd5fcaf 100644
--- a/include/interpreter_tree.hpp
+++ b/include/interpreter_tree.hpp
@@ -297,6 +297,7 @@ struct AliasDefinitionStatement {
   std::vector<AbstractTypeIdentifier> parameters;
   std::unique_ptr<ParametrizedType> value;
 
+  std::vector<utils::IdType> parameter_graph_ids_;
   utils::IdType type_id_;
 };
 
@@ -321,6 +322,7 @@ struct FunctionDefinitionStatement {
   SuperExpression value;
 
   utils::IdType function_id_;
+  std::vector<utils::IdType> argument_graph_ids_;
 };
 
 struct TypeDefinitionStatement {
@@ -335,6 +337,7 @@ struct AbstractTypeDefinitionStatement {
   enum { Basic, Abstract } modifier;
   std::unique_ptr<AnnotatedType> type;
 
+  utils::IdType type_graph_id_;
   utils::IdType type_id_;
 };
 
@@ -362,6 +365,8 @@ struct TypeDefinition {
 struct AnnotatedAbstractType {
   AbstractTypeIdentifier type;
   std::vector<TypeclassUsage> typeclasses;
+
+  utils::IdType type_graph_id_;
 };
 
 // ----------------- Flow control -----------------
@@ -518,6 +523,8 @@ struct TypeExpression {
   std::vector<TypeSubExpression> namespaces;
   AnyTypeIdentifier type;
   std::optional<size_t> array_size; // if array; 0 - dynamic size
+
+  utils::IdType type_id_;
 };
 
 struct ExtendedScopedAnyType {
@@ -535,6 +542,8 @@ struct ParametrizedTypeclass {
 struct TypeclassExpression {
     std::vector<TypeSubExpression> namespaces;
     TypeclassIdentifier typeclass;
+
+    utils::IdType type_id_;
 };
 
 // ----------------- Comments [IGNORE] -----------------
diff --git a/include/link_symbols_visitor.hpp b/include/link_symbols_visitor.hpp
index 42801f8..f723e19 100644
--- a/include/link_symbols_visitor.hpp
+++ b/include/link_symbols_visitor.hpp
@@ -3,15 +3,17 @@
 #include <ostream>
 
 // for clangd
+#include "abstract_types_context.hpp"
 #include "visitor.hpp"
-
+#include "global_info.hpp"
 
 namespace interpreter {
 
 // TODO, (maybe add VisitSourceFile?)
 class LinkSymbolsVisitor : public Visitor {
 public:
-  explicit LinkSymbolsVisitor() {}
+  explicit LinkSymbolsVisitor(info::GlobalInfo& global_info)
+    : namespace_visitor_(global_info.CreateVisitor()) {}
 
 private:
   // Sources -----------------
@@ -102,16 +104,18 @@ private:
 
   // Identifiers, constants, etc. -----------------
 
-  void Visit(ExtendedName* node) override;
-
-  void Visit(std::string* node) override; // std::string
-
-  void Visit(FloatNumberLiteral* node) override;
-  void Visit(NumberLiteral* node) override;
-  void Visit(StringLiteral* node) override;
-  void Visit(CharLiteral* node) override;
+  // // void Visit(ExtendedName* node) override;
+  // //
+  // // void Visit(std::string* node) override; // std::string
+  // //
+  // // void Visit(FloatNumberLiteral* node) override;
+  // // void Visit(NumberLiteral* node) override;
+  // // void Visit(StringLiteral* node) override;
+  // // void Visit(CharLiteral* node) override;
 
 private:
+  info::GlobalInfo::NamespaceVisitor namespace_visitor_;
+  info::AbstractTypesContextManager abstract_types_;
 };
 
 } // namespace interpreter
diff --git a/include/type_graph.hpp b/include/type_graph.hpp
index 78e8937..19cfe23 100644
--- a/include/type_graph.hpp
+++ b/include/type_graph.hpp
@@ -15,13 +15,11 @@ namespace info {
 
 class TypeGraph {
 public:
-  size_t AddVertex(const std::vector<std::string>& path,
-                   const std::vector<std::string>& methods = {},
+  size_t AddVertex(const std::vector<std::string>& methods = {},
                    const std::vector<std::string>& typeclasses = {}) {
     is_calculated_ = false;
 
     Vertex vertex;
-    vertex.path = path;
 
     for (auto& method : methods) {
       vertex.new_requirements.methods.insert(storage_.GetId(method));
@@ -35,14 +33,9 @@ public:
     edges_.emplace_back();
     back_edges_.emplace_back();
 
-    verticle_ids_[vertex.path] = verticles_.size() - 1;
     return verticles_.size() - 1;
   }
 
-  size_t FindVertex(const std::vector<std::string>& path) {
-    return verticle_ids_[path];
-  }
-
   std::vector<std::string> VertexMethods(size_t id) {
     if (!is_calculated_) {
       // error
@@ -162,7 +155,6 @@ private:
   };
 
   struct Vertex {
-    std::vector<std::string> path;
     RequirementsData new_requirements;
     std::optional<size_t> cluster;
   };
@@ -212,7 +204,6 @@ private:
   }
 
 private:
-  std::unordered_map<std::vector<std::string>,  size_t> verticle_ids_;
   std::vector<std::vector<size_t>> edges_;
   std::vector<std::vector<size_t>> back_edges_;
   std::vector<Vertex> verticles_;
diff --git a/src/find_symbols_visitor.cpp b/src/find_symbols_visitor.cpp
index 8029194..f15b7ad 100644
--- a/src/find_symbols_visitor.cpp
+++ b/src/find_symbols_visitor.cpp
@@ -54,6 +54,7 @@ void FindSymbolsVisitor::Visit(Namespace* node) {
 
 // Definitions -----------------
 
+// TODO: add imported symbols to symbol table (global info)
 void FindSymbolsVisitor::Visit(ImportStatement* node) {
   is_in_statement = true;
 
@@ -65,8 +66,6 @@ void FindSymbolsVisitor::Visit(ImportStatement* node) {
   is_in_statement = false;
 }
 
-// <-- current position
-
 void FindSymbolsVisitor::Visit(AliasDefinitionStatement* node) {
   is_in_statement = true;
 
@@ -86,6 +85,11 @@ void FindSymbolsVisitor::Visit(AliasDefinitionStatement* node) {
       break;
   }
   alias_info.parameters = node->parameters;
+  node->parameter_graph_ids_.resize(node->parameters.size());
+  for (size_t i = 0; i < node->parameters.size(); ++i) {
+    node->parameter_graph_ids_[i] = namespace_visitor_.GetAbstractTypeGraph()->AddVertex();
+  }
+
   alias_info.value.node = node->value.get();
 
   info.type = std::move(alias_info);
@@ -136,8 +140,10 @@ void FindSymbolsVisitor::Visit(FunctionDefinitionStatement* node) {
   }
 
   info.argument_names.resize(definition->arguments.size());
+  node->argument_graph_ids_.resize(definition->arguments.size());
   for (size_t i = 0; i < definition->arguments.size(); ++i) {
     info.argument_names[i] = definition->arguments[i].name;
+    node->argument_graph_ids_[i] = namespace_visitor_.GetAbstractTypeGraph()->AddVertex();
   }
 
   info.expression = &node->value;
@@ -202,6 +208,7 @@ void FindSymbolsVisitor::Visit(AbstractTypeDefinitionStatement* node) {
 
   info.type = std::move(abstract_type_info);
 
+  node->type_graph_id_ = namespace_visitor_.GetAbstractTypeGraph()->AddVertex(); // ??
   node->type_id_ = namespace_visitor_.AddType(type, std::move(info));
 
   is_in_statement = false;
@@ -245,6 +252,8 @@ void FindSymbolsVisitor::Visit(AnyAnnotatedType* node) {
     info.typeclass_nodes[i] = &node->typeclasses[i];
   }
 
+  node->type_graph_id_ = namespace_visitor_.GetAbstractTypeGraph()->AddVertex();
+
   current_info_ = std::move(info);
 }
 
diff --git a/src/global_info.cpp b/src/global_info.cpp
index dbf1a42..a2f7e02 100644
--- a/src/global_info.cpp
+++ b/src/global_info.cpp
@@ -28,10 +28,12 @@ void GlobalInfo::NamespaceVisitor::AddEnterNamespace(const std::string& name,
   }
 
   namespace_info->type_name = name;
+  current_path_.push_back(name);
 }
 
 void GlobalInfo::NamespaceVisitor::EnterNamespace(const std::string& name) { // TODO: enter sibling namespace, etc.
   namespace_stack_.push_back(&namespace_stack_.back()->namespaces[name]);
+  current_path_.push_back(name);
 }
 
 void GlobalInfo::NamespaceVisitor::ExitNamespace() {
@@ -41,10 +43,13 @@ void GlobalInfo::NamespaceVisitor::ExitNamespace() {
   }
 
   namespace_stack_.pop_back();
+  current_path_.pop_back();
 }
 
 void GlobalInfo::NamespaceVisitor::ToGlobalNamespace() {
   namespace_stack_.clear();
+  current_path_.clear();
+
   namespace_stack_.push_back(&global_info_.global_namespace_);
 }
 
diff --git a/src/link_symbols_visitor.cpp b/src/link_symbols_visitor.cpp
index 9c7542f..1934779 100644
--- a/src/link_symbols_visitor.cpp
+++ b/src/link_symbols_visitor.cpp
@@ -1,12 +1,12 @@
 // for clangd
 #include "../include/link_symbols_visitor.hpp"
+#include "../include/error_handling.hpp"
 
 namespace interpreter {
 
 // Sources -----------------
 
 void LinkSymbolsVisitor::Visit(SourceFile* node) {
-  out_ << "[SourceFile] (\n\n";
   for (auto& statement : node->statements) {
     if (std::holds_alternative<Partition>(statement)) {
       Visit(&std::get<Partition>(statement));
@@ -16,523 +16,267 @@ void LinkSymbolsVisitor::Visit(SourceFile* node) {
       // error
     }
   }
-  out_ << "\n)\n";
 }
 
 void LinkSymbolsVisitor::Visit(Sources* node) {
-  out_ << "[Sources](\n";
+  abstract_types_.EnterContext();
   for (auto& statement : node->statements) {
     Visitor::Visit(statement);
   }
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 // Namespaces, partitions -----------------
 
 void LinkSymbolsVisitor::Visit(Partition* node) {
-  out_ << "[Partition] ";
-  switch (node->name) {
-    case Partition::Test:
-      out_ << "TEST";
-      break;
-    case Partition::Interface:
-      out_ << "INTERFACE";
-      break;
-    case Partition::Core:
-      out_ << "CORE";
-      break;
-    case Partition::Lib:
-      out_ << "LIB";
-      break;
-    case Partition::Module:
-      out_ << "MODULE";
-      break;
-    case Partition::Exe:
-      out_ << "EXE";
-      break;
-  }
-  out_ << " {\n";
+  // TODO
   Visit(node->scope.get());
-  out_ << "}\n";
 }
 
 void LinkSymbolsVisitor::Visit(Namespace* node) {
-  out_ << "[Namespace] ";
-  if (node->name.has_value()) {
-    if (node->modifier.has_value()) {
-      switch (node->modifier.value()) {
-        case Namespace::Const:
-          out_ << "const ";
-          break;
-        case Namespace::Var:
-          out_ << "var ";
-          break;
-      }
-    } else {
-      // error
-    }
-    Visit(&node->name.value());
-  }
-  Visit(&node->type);
-  out_ << "{\n";
+  namespace_visitor_.EnterNamespace(node->type);
   Visit(node->scope.get());
-  out_ << "}\n";
+  namespace_visitor_.ExitNamespace();
 }
 
 // Definitions -----------------
 
-void LinkSymbolsVisitor::Visit(ImportStatement* node) {
-  if (node->name.has_value()) {
-    out_ << "[Use " << node->name.value() << "] = ";
-  }
-  out_ << "[Import " << node->module_name << "]";
-  if (!node->symbols.empty()) {
-    out_ << " (\n";
-    for (auto& symbol : node->symbols) {
-      Visit(&symbol);
-      out_ << '\n';
-    }
-    out_ << ')';
-  }
-  out_ << '\n';
-}
+void LinkSymbolsVisitor::Visit(ImportStatement* node) {}
 
 void LinkSymbolsVisitor::Visit(AliasDefinitionStatement* node) {
-  out_ << "[Alias ";
-  switch (node->modifier) {
-    case AliasDefinitionStatement::Alias:
-    out_ << "alias";
-    break;
-    case AliasDefinitionStatement::Type:
-    out_ << "type";
-    break;
-    case AliasDefinitionStatement::Let:
-    out_ << "let";
-    break;
+  abstract_types_.EnterContext();
+  for (size_t i = 0; i <node->parameters.size(); ++i) {
+    abstract_types_.DefineType(node->parameters[i], node->parameter_graph_ids_[i]);
   }
-  out_ << ' ';
-  Visit(&node->type);
-  out_ << "] = (";
   Visit(node->value.get());
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 void LinkSymbolsVisitor::Visit(VariableDefinitionStatement* node) {
-  out_ << "[Variable ";
-  switch (node->modifier) {
-    case VariableDefinitionStatement::Const:
-    out_ << "const";
-    break;
-    case VariableDefinitionStatement::Var:
-    out_ << "var";
-    break;
-  }
-  out_ << ' ';
+  abstract_types_.EnterContext();
   Visitor::Visit(node->name);
-  out_ << "] = (";
   Visitor::Visit(node->value);
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 void LinkSymbolsVisitor::Visit(FunctionDeclaration* node) {
-  out_ << "[FunctionDeclaration ";
-  Visit(&node->name);
-  out_ << "] (";
+  abstract_types_.EnterContext();
   for (auto& parameter : node->parameters) {
     Visit(parameter.get());
+    abstract_types_.DefineType(parameter->type, parameter->type_graph_id_);
   }
-  out_ << ") : (";
   Visit(node->type.get());
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 void LinkSymbolsVisitor::Visit(FunctionDefinitionStatement* node) {
-  out_ << "[Function] (";
+  abstract_types_.EnterContext();
   Visit(node->definition.get());
-  out_ << ") = (";
   Visitor::Visit(node->value);
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 void LinkSymbolsVisitor::Visit(TypeDefinitionStatement* node) {
-  out_ << "[Type ";
-  switch (node->modifier) {
-    case TypeDefinitionStatement::Struct:
-    out_ << "struct";
-    break;
-    case TypeDefinitionStatement::Class:
-    out_ << "class";
-    break;
-  }
-  out_ << "] (";
+  abstract_types_.EnterContext();
   Visit(node->definition.get());
-  out_ << ") = (";
   Visitor::Visit(node->value);
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 void LinkSymbolsVisitor::Visit(AbstractTypeDefinitionStatement* node) {
-  out_ << "[AbstractType ";
-  switch (node->modifier) {
-    case AbstractTypeDefinitionStatement::Basic:
-    out_ << "basic";
-    break;
-    case AbstractTypeDefinitionStatement::Abstract:
-    out_ << "abstract";
-    break;
-  }
-  out_ << "] (";
   Visit(node->type.get());
-  out_ << ")\n";
+  // TODO: can't be used before definition
+  abstract_types_.DefineType(node->type->type, node->type->type_graph_id_);
 }
 
 void LinkSymbolsVisitor::Visit(TypeclassDefinitionStatement* node) {
-  out_ << "[Typeclass] (";
+  abstract_types_.EnterContext();
   Visit(node->definition.get());
-  if (!node->requirements.empty()) {
-    out_ << ") : (\n";
-  }
   for (auto& requirement : node->requirements) {
-    out_ << "& ";
     Visit(requirement.get());
-    out_ << "\n";
   }
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 // Definition parts
 
 void LinkSymbolsVisitor::Visit(FunctionDefinition* node) {
-  out_ << "[FunctionDefinition ";
-  switch (node->modifier) {
-    case FunctionDefinition::Operator:
-    out_ << "operator";
-    break;
-    case FunctionDefinition::Function:
-    out_ << "function";
-    break;
+  for (auto& parameter : node->parameters) {
+    Visit(parameter.get());
+    abstract_types_.DefineType(parameter->type, parameter->type_graph_id_);
   }
-  out_ << ' ';
-  Visit(&node->name);
-  out_ << "]";
-  if (!node->parameters.empty()) {
-    out_ << " (";
-    for (auto& parameter : node->parameters) {
-      Visit(parameter.get());
-    }
-    out_ << ')';
-  }
-  if (!node->arguments.empty()) {
-    out_ << " : (";
-    for (auto& argument : node->arguments) {
-      Visit(&argument);
-    }
-    out_ << ')';
-  }
-  out_ << ' ';
 }
 
 void LinkSymbolsVisitor::Visit(TypeDefinition* node) {
-  out_ << "[TypeDefinition] (";
   Visit(node->type.get());
-  out_ << ')';
-  if (!node->parameters.empty()) {
-    out_ << '(';
-    for (auto& parameter : node->parameters) {
-      Visit(parameter.get());
-    }
-    out_ << ')';
+  for (auto& parameter : node->parameters) {
+    Visit(parameter.get());
+    abstract_types_.DefineType(parameter->type, parameter->type_graph_id_);
   }
-  out_ << ' ';
 }
 
 void LinkSymbolsVisitor::Visit(AnyAnnotatedType* node) {
-  out_ << "[Annotated (Abstract) Type ";
-  Visit(&node->type);
-  out_ << ']';
+  // TODO check ??
   if (!node->typeclasses.empty() > 0) {
-    out_ << " (";
     for (auto& typeclass : node->typeclasses) {
       Visitor::Visit(typeclass);
     }
-    out_ << ')';
   }
-  out_ << ' ';
 }
 
 // Flow control -----------------
 
 void LinkSymbolsVisitor::Visit(MatchCase* node) {
-  out_ << "[MatchCase | ";
   Visitor::Visit(node->value);
   if (node->condition.has_value()) {
-    out_ << " ? ";
     Visitor::Visit(node->condition.value());
   }
   if (node->statement.has_value()) {
-    out_ << " -> ";
     Visitor::Visit(node->statement.value());
   }
-  out_ << "]\n";
 }
 
 void LinkSymbolsVisitor::Visit(Match* node) {
-  out_ << "[Match] (";
   Visitor::Visit(node->value);
-  out_ << ") [with] (\n";
   for (auto& match_case : node->matches) {
     Visit(&match_case);
   }
-  out_ << ")\n";
 }
 
 void LinkSymbolsVisitor::Visit(Condition* node) {
-  out_ << "[If] (";
   Visitor::Visit(node->conditions[0]);
-  out_ << ") [then] (\n";
   Visitor::Visit(node->statements[0]);
-  out_ << ')';
   for (size_t i = 1; i < node->conditions.size(); ++i) {
-      out_ << " [elif] (";
       Visitor::Visit(node->conditions[i]);
-      out_ << ") [then] (\n";
       Visitor::Visit(node->statements[i]);
-      out_ << ')';
   }
   if (node->statements.size() > node->conditions.size()) {
-    out_ << " [else] (\n";
     Visitor::Visit(node->statements[node->conditions.size()]);
-    out_ << ')';
   }
-  out_ << '\n';
 }
 
 void LinkSymbolsVisitor::Visit(DoWhileLoop* node) {
-  out_ << "[Do] (\n";
   Visitor::Visit(node->statement);
-  out_ << ") [while] (";
   Visitor::Visit(node->condition);
-  out_ << ")\n";
 }
 
 void LinkSymbolsVisitor::Visit(WhileLoop* node) {
-  out_ << "[While] (";
-  Visitor::Visit(node->statement);
-  out_ << ") [do] (\n";
   Visitor::Visit(node->condition);
-  out_ << ")\n";
+  Visitor::Visit(node->statement);
 }
 void LinkSymbolsVisitor::Visit(ForLoop* node) {
-  out_ << "[For] (";
   Visitor::Visit(node->variable);
-  out_ << ") [in] (";
   Visitor::Visit(node->interval);
-  out_ << ") [do] (\n";
   Visitor::Visit(node->statement);
-  out_ << ")\n";
 }
 
 void LinkSymbolsVisitor::Visit(LoopLoop* node) {
-  out_ << "[Loop] (\n";
   Visitor::Visit(node->statement);
-  out_ << ")\n";
 }
 
 // Statements, expressions, blocks, etc. -----------------
 
 void LinkSymbolsVisitor::Visit(Block* node) {
-  out_ << "[Block] {\n";
   for (auto& statement : node->statements) {
     Visitor::Visit(statement);
   }
-  out_ << "}\n";
 }
 
 void LinkSymbolsVisitor::Visit(ScopedStatement* node) {
-  out_ << "[Scoped] ( ";
   Visitor::Visit(node->statement);
-  out_ << ")\n";
 }
 
-void LinkSymbolsVisitor::Visit(LoopControlExpression& node) { // enum
-  switch (node) {
-    case LoopControlExpression::Break:
-      out_ << "[Break]\n";
-      break;
-    case LoopControlExpression::Continue:
-      out_ << "[Continue]\n";
-      break;
-  }
-}
+void LinkSymbolsVisitor::Visit(LoopControlExpression& node) {}
 
 // Operators
 
 void LinkSymbolsVisitor::Visit(BinaryOperatorExpression* node) {
-  out_ << "[BinaryOperator] (";
   Visitor::Visit(node->left_expression);
-  out_ << ") [";
-  Visit(&node->operator_name);
-  out_ << "] (";
   Visitor::Visit(node->right_expression);
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(UnaryOperatorExpression* node) {
-  out_ << "[UnaryOperator ";
-  Visit(&node->operator_name);
-  out_ << "] (";
   Visitor::Visit(node->expression);
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(ReferenceExpression* node) {
-  out_ << "[ReferenceExpression ";
-  for (auto& reference : node->references) {
-    switch (reference) {
-      case ReferenceType::Reference:
-      out_ << '~';
-      break;
-      case ReferenceType::UniqueReference:
-      out_ << '@';
-      break;
-    }
-  }
-  out_ << "] (";
   Visit(node->expression.get());
-  out_ << ')';
 }
 
 // Other Expressions
 
 void LinkSymbolsVisitor::Visit(FunctionCallExpression* node) {
-  out_ << "[FunctionCall ";
   Visit(node->name.get());
-  out_ << "] (";
   for (auto& argument : node->arguments) {
     Visitor::Visit(argument);
-    out_ << ", ";
   }
-  out_ << ")";
 }
 
 void LinkSymbolsVisitor::Visit(TupleExpression* node) {
-  out_ << "[TupleExpression] (";
   for (auto& expression : node->expressions) {
-    out_ << "&";
     Visitor::Visit(expression);
   }
-  out_ << ")";
 }
 
 void LinkSymbolsVisitor::Visit(VariantExpression* node) {
-  out_ << "[VariantExpression] (";
   for (auto& expression : node->expressions) {
-    out_ << "|";
     Visitor::Visit(expression);
   }
-  out_ << ")";
 }
 
 void LinkSymbolsVisitor::Visit(ReturnExpression* node) {
-  out_ << "[Return] (";
   Visitor::Visit(node->expression);
-  out_ << ")\n";
 }
 
 void LinkSymbolsVisitor::Visit(TypeConstructor* node) {
-  out_ << "[TypeConstructor ";
   Visit(node->type.get());
-  out_ << "]\n(";
-
-  bool is_first = true;
   for (auto& parameter : node->parameters) {
-    if (!is_first) {
-      out_ << ")\n";
-      is_first = false;
-    }
-    out_ << '(';
-    Visit(&std::get<0>(parameter));
-    switch (std::get<1>(parameter)) {
-      case TypeConstructor::Assign:
-      out_ << " = ";
-      break;
-      case TypeConstructor::Move:
-      out_ << " <- ";
-      break;
-    }
     Visitor::Visit(std::get<2>(parameter));
   }
-  out_ << ")\n";
 }
 
 void LinkSymbolsVisitor::Visit(LambdaFunction* node) {
-  out_ << "[LambdaFunction] (";
+  abstract_types_.EnterContext();
   for (auto& parameter : node->parameters) {
     Visit(parameter.get());
+    abstract_types_.DefineType(parameter->type, parameter->type_graph_id_);
   }
-  if (!node->parameters.empty()) {
-    out_ << ") : (";
-  }
-  for (auto& argument : node->arguments) {
-    Visit(&argument);
-  }
-  out_ << ") -> (\n";
   Visitor::Visit(node->expression);
-  out_ << ")\n";
+  abstract_types_.ExitContext();
 }
 
 void LinkSymbolsVisitor::Visit(ArrayExpression* node) {
-  out_ << "[ArrayExpression] ([";
   for (auto& element : node->elements) {
     Visitor::Visit(element);
-    out_ << ';';
   }
-  out_ << "])";
 }
 
 // Name
 
 void LinkSymbolsVisitor::Visit(NameExpression* node) {
-  out_ << "[NameExpression] (";
   for (auto& variable_namespace : node->namespaces) {
     Visitor::Visit(variable_namespace);
-    out_ << '.';
   }
-  for (size_t i = 0; i < node->expressions.size(); ++i) {
-    Visitor::Visit(node->expressions[i]);
-    if (i + 1 < node->expressions.size()) {
-      out_ << '.';
-    }
+  for (auto& expression : node->expressions) {
+    Visitor::Visit(expression);
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(TupleName* node) {
-  out_ << "[TupleName] (";
   for (auto& name : node->names) {
-    out_ << "& ";
     Visitor::Visit(name);
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(VariantName* node) {
-  out_ << "[VariantName] (";
   for (auto& name : node->names) {
-    out_ << "| ";
     Visitor::Visit(name);
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(AnnotatedName* node) {
-  out_ << "[AnnotatedName ";
-  Visit(&node->name);
-  out_ << ']';
   if (node->type.has_value()) {
-    out_ << " : (";
     Visitor::Visit(node->type.value());
-    out_ << ')';
   }
 }
 
@@ -541,143 +285,117 @@ void LinkSymbolsVisitor::Visit(AnnotatedName* node) {
 // Type
 
 void LinkSymbolsVisitor::Visit(FunctionType* node) {
-  out_ << "[FunctionType] (";
-  bool is_first = true;
   for (auto& type : node->types) {
-    if (!is_first) {
-      out_ << " -> ";
-    }
-    is_first = false;
     Visitor::Visit(type);
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(TupleType* node) {
-  out_ << "[TupleType ";
-  if (node->type.has_value()) {
-    Visit(&node->type.value());
-  }
-  out_ << "] (";
   for (auto& entity : node->entities) {
-    out_ << "& ";
-    if (entity.first.has_value()) {
-      Visit(&entity.first.value());
-      out_ << " : ";
-    }
     Visit(entity.second.get());
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(VariantType* node) {
-  out_ << "[VariantType ";
-  if (node->type.has_value()) {
-    Visit(&node->type.value());
-  }
-  out_ << "] (";
   for (auto& constructor : node->constructors) {
-    out_ << "| ";
     if (std::holds_alternative<Constructor>(constructor)) {
-      Visit(&std::get<Constructor>(constructor));
+      // do nothing
     } else if (std::holds_alternative<std::unique_ptr<TupleType>>(constructor)) {
       Visit(std::get<std::unique_ptr<TupleType>>(constructor).get());
     } else {
       // error
     }
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(ParametrizedType* node) {
-  out_ << "[ParametrizedType] (";
   Visit(node->type_expression.get());
   for (auto& parameter : node->parameters) {
-    out_ << ' ';
     Visitor::Visit(parameter);
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(TypeExpression* node) {
-  out_ << "[TypeExpression ";
+  std::vector<std::string> path;
+  path.reserve(node->namespaces.size());
 
-  if (node->array_size.has_value()) {
-    out_ << "[array size: " << node->array_size.value() << ']';
-  }
-
-  out_ << "] (";
   for (auto& type_namespace : node->namespaces) {
     Visitor::Visit(type_namespace);
-    out_ << '.';
+    if (std::holds_alternative<std::unique_ptr<std::string>>(type_namespace)) {
+      path.push_back(*std::get<std::unique_ptr<std::string>>(type_namespace));
+    } else if (std::holds_alternative<std::unique_ptr<ParametrizedType>>(type_namespace)) {
+      path.push_back(std::get<std::unique_ptr<ParametrizedType>>(type_namespace)->type_expression->type);
+    } else {
+      // error
+    }
+  }
+
+  std::optional<utils::IdType> maybe_type = namespace_visitor_.FindType(path, node->type);
+  std::optional<utils::IdType> maybe_abstract_type = std::nullopt;
+
+  if (path.size() == 0) {
+    maybe_abstract_type = abstract_types_.GetTypeId(node->type);
+  }
+
+  if (maybe_abstract_type.has_value()) {
+    if (maybe_type.has_value()) {
+      error_handling::HandleTypecheckError("Ambigious type");
+    } else {
+      node->type_id_ = maybe_abstract_type.value();
+    }
+  } else if (maybe_type.has_value()) {
+    node->type_id_ = maybe_type.value();
+  } else {
+    error_handling::HandleTypecheckError("Type not found");
   }
-  Visit(&node->type);
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(ExtendedScopedAnyType* node) {
-  out_ << "[ExtendedScopedAnyType ";
-  for (auto& reference : node->references) {
-    switch (reference) {
-      case ReferenceType::Reference:
-      out_ << '~';
-      break;
-      case ReferenceType::UniqueReference:
-      out_ << '@';
-      break;
-    }
-  }
-  out_ << "] (";
   Visitor::Visit(node->type);
-  out_ << ')';
 }
 
 // Typeclass
 
 void LinkSymbolsVisitor::Visit(ParametrizedTypeclass* node) {
-  out_ << "[ParametrizedTypeclass] (";
   Visit(node->typeclass_expression.get());
-  for (auto& paramater : node->parameters) {
-    out_ << ' ';
-    Visitor::Visit(paramater);
+  for (auto& parameter : node->parameters) {
+    Visitor::Visit(parameter);
   }
-  out_ << ')';
 }
 
 void LinkSymbolsVisitor::Visit(TypeclassExpression* node) {
-  out_ << "[TypeclassExpression] (";
+  std::vector<std::string> path;
+  path.reserve(node->namespaces.size());
+
   for (auto& typeclass_namespace : node->namespaces) {
     Visitor::Visit(typeclass_namespace);
-    out_ << '.';
+    if (std::holds_alternative<std::unique_ptr<std::string>>(typeclass_namespace)) {
+      path.push_back(*std::get<std::unique_ptr<std::string>>(typeclass_namespace));
+    } else if (std::holds_alternative<std::unique_ptr<ParametrizedType>>(typeclass_namespace)) {
+      path.push_back(std::get<std::unique_ptr<ParametrizedType>>(typeclass_namespace)->type_expression->type);
+    } else {
+      // error
+    }
   }
-  Visit(&node->typeclass);
-  out_ << ')';
-}
 
-// Identifiers, constants, etc. -----------------
+  std::optional<utils::IdType> maybe_typeclass = namespace_visitor_.FindType(path, node->typeclass);
+  std::optional<utils::IdType> maybe_abstract_typeclass = std::nullopt;
 
-void LinkSymbolsVisitor::Visit(ExtendedName* node) {
-  out_ << "[ExtendedName " << node->name << "] ";
-}
+  if (path.size() == 0) {
+    maybe_abstract_typeclass = abstract_types_.GetTypeId(node->typeclass);
+  }
 
-void LinkSymbolsVisitor::Visit(std::string* node) { // std::string
-  out_ << "[Identifier " << *node << "] ";
-}
-
-void LinkSymbolsVisitor::Visit(FloatNumberLiteral* node) {
-  out_ << "[FloatNumber " << node->value << "] ";
-}
-
-void LinkSymbolsVisitor::Visit(NumberLiteral* node) {
-  out_ << "[Number " << node->value << "] ";
-}
-
-void LinkSymbolsVisitor::Visit(StringLiteral* node) {
-  out_ << "[String " << node->value << "] ";
-}
-
-void LinkSymbolsVisitor::Visit(CharLiteral* node) {
-  out_ << "[Char " << node->value << "] ";
+  if (maybe_abstract_typeclass.has_value()) {
+    if (maybe_typeclass.has_value()) {
+      error_handling::HandleTypecheckError("Ambigious type");
+    } else {
+      node->type_id_ = maybe_abstract_typeclass.value();
+    }
+  } else if (maybe_typeclass.has_value()) {
+    node->type_id_ = maybe_typeclass.value();
+  } else {
+    error_handling::HandleTypecheckError("Type not found");
+  }
 }
 
 } // namespace interpreter
diff --git a/src/print_visitor.cpp b/src/print_visitor.cpp
index f7081d2..9948889 100644
--- a/src/print_visitor.cpp
+++ b/src/print_visitor.cpp
@@ -317,9 +317,9 @@ void PrintVisitor::Visit(DoWhileLoop* node) {
 
 void PrintVisitor::Visit(WhileLoop* node) {
   out_ << "[While] (";
-  Visitor::Visit(node->statement);
-  out_ << ") [do] (\n";
   Visitor::Visit(node->condition);
+  out_ << ") [do] (\n";
+  Visitor::Visit(node->statement);
   out_ << ")\n";
 }
 void PrintVisitor::Visit(ForLoop* node) {
@@ -637,9 +637,9 @@ void PrintVisitor::Visit(ExtendedScopedAnyType* node) {
 void PrintVisitor::Visit(ParametrizedTypeclass* node) {
   out_ << "[ParametrizedTypeclass] (";
   Visit(node->typeclass_expression.get());
-  for (auto& paramater : node->parameters) {
+  for (auto& parameter : node->parameters) {
     out_ << ' ';
-    Visitor::Visit(paramater);
+    Visitor::Visit(parameter);
   }
   out_ << ')';
 }