diff --git a/boot/ast.cc b/boot/ast.cc
index 20b755c..d3e0b9f 100644
--- a/boot/ast.cc
+++ b/boot/ast.cc
@@ -464,7 +464,8 @@ namespace boot
         return *m_base;
     }
 
-    record_type_expression::record_type_expression(const struct position position, fields_t&& fields)
+    record_type_expression::record_type_expression(const struct position position,
+            std::vector<field_declaration>&& fields)
         : type_expression(position), fields(std::move(fields))
     {
     }
@@ -479,7 +480,8 @@ namespace boot
         return std::static_pointer_cast<record_type_expression>(shared_from_this());
     }
 
-    union_type_expression::union_type_expression(const struct position position, fields_t&& fields)
+    union_type_expression::union_type_expression(const struct position position,
+            std::vector<field_declaration>&& fields)
         : type_expression(position), fields(std::move(fields))
     {
     }
diff --git a/boot/parser.yy b/boot/parser.yy
index 13f9fe7..e5ed856 100644
--- a/boot/parser.yy
+++ b/boot/parser.yy
@@ -145,7 +145,7 @@ along with GCC; see the file COPYING3.  If not see
 %type <elna::boot::type_definition *> type_definition;
 %type <std::vector<elna::boot::type_definition *>> type_definitions type_part;
 %type <elna::boot::block *> block;
-%type <elna::boot::field_t> field_declaration;
+%type <elna::boot::field_declaration> field_declaration;
 %type <std::vector<std::pair<std::string, std::shared_ptr<elna::boot::type_expression>>>>
     optional_fields required_fields;
 %type <std::vector<elna::boot::conditional_statements *>> elsif_then_statements elsif_do_statements;
diff --git a/boot/semantic.cc b/boot/semantic.cc
index 6735976..9489625 100644
--- a/boot/semantic.cc
+++ b/boot/semantic.cc
@@ -21,33 +21,104 @@ namespace elna
 {
 namespace boot
 {
-    alias_type *type::is_alias()
-    {
-        return nullptr;
-    }
-
-    primitive_type *type::is_primitive()
-    {
-        return nullptr;
-    }
-
-    record_type *type::is_record()
-    {
-        return nullptr;
-    }
-
-    union_type *type::is_union()
-    {
-        return nullptr;
-    }
-
-    type::~type()
+    type::type(alias_type *alias)
+        : payload({ .alias = alias }), tag(type_tag::alias)
     {
     }
 
-    alias_type *alias_type::is_alias()
+    type::type(primitive_type *primitive)
+        : payload({ .primitive = primitive }), tag(type_tag::primitive)
+    {
+    }
+
+    type::type(record_type *record)
+        : payload({ .record = record }), tag(type_tag::record)
+    {
+    }
+
+    type::type(union_type *_union)
+        : payload({ ._union = _union }), tag(type_tag::_union)
+    {
+    }
+
+    type::type(pointer_type *pointer)
+        : payload({ .pointer = pointer }), tag(type_tag::pointer)
+    {
+    }
+
+    template<>
+    alias_type *const type::get<alias_type>() const
+    {
+        if (tag == type_tag::alias)
+        {
+            return payload.alias;
+        }
+        else
+        {
+            return nullptr;
+        }
+    }
+
+    template<>
+    primitive_type *const type::get<primitive_type>() const
+    {
+        if (tag == type_tag::primitive)
+        {
+            return payload.primitive;
+        }
+        else
+        {
+            return nullptr;
+        }
+    }
+
+    template<>
+    record_type *const type::get<record_type>() const
+    {
+        if (tag == type_tag::record)
+        {
+            return payload.record;
+        }
+        else
+        {
+            return nullptr;
+        }
+    }
+
+    template<>
+    union_type *const type::get<union_type>() const
+    {
+        if (tag == type_tag::_union)
+        {
+            return payload._union;
+        }
+        else
+        {
+            return nullptr;
+        }
+    }
+
+    template<>
+    pointer_type *const type::get<pointer_type>() const
+    {
+        if (tag == type_tag::pointer)
+        {
+            return payload.pointer;
+        }
+        else
+        {
+            return nullptr;
+        }
+    }
+
+    bool type::empty() const
+    {
+        return tag == type_tag::empty;
+    }
+
+    pointer_type::pointer_type(type base)
+        : base(base)
     {
-        return this;
     }
 
     primitive_type::primitive_type(const std::string& identifier)
@@ -55,19 +126,67 @@ namespace boot
     {
     }
 
-    primitive_type *primitive_type::is_primitive()
+    void declaration_visitor::visit(program *program)
     {
-        return this;
+        for (type_definition *const type : program->types)
+        {
+            this->unresolved.insert({ type->identifier, new alias_type() });
+        }
+        for (type_definition *const type : program->types)
+        {
+            type->accept(this);
+        }
     }
 
-    record_type *record_type::is_record()
+    void declaration_visitor::visit(type_definition *definition)
     {
-        return this;
+        auto unresolved_declaration = this->unresolved.at(definition->identifier);
+
+        definition->body().accept(this);
+
+        unresolved_declaration->reference = this->current_type;
     }
 
-    union_type *union_type::is_union()
+    void declaration_visitor::visit(primitive_type_expression *type_expression)
+    {
+        auto unresolved_alias = this->unresolved.find(type_expression->name);
+
+        if (unresolved_alias != this->unresolved.end())
+        {
+            this->current_type = type(unresolved_alias->second);
+        }
+        else
+        {
+            this->current_type = type(new primitive_type(type_expression->name));
+        }
+    }
+
+    void declaration_visitor::visit(array_type_expression *type_expression)
+    {
+    }
+
+    void declaration_visitor::visit(pointer_type_expression *type_expression)
+    {
+        type_expression->base().accept(this);
+        this->current_type = type(new pointer_type(this->current_type));
+    }
+
+    void declaration_visitor::visit(record_type_expression *type_expression)
+    {
+        auto type_definition = new record_type();
+
+        this->current_type = type(type_definition);
+    }
+
+    void declaration_visitor::visit(union_type_expression *type_expression)
+    {
+        auto type_definition = new union_type();
+
+        this->current_type = type(type_definition);
+    }
+
+    void declaration_visitor::visit(procedure_type_expression *type_expression)
     {
-        return this;
     }
 }
 }
diff --git a/gcc/elna-generic.cc b/gcc/elna-generic.cc
index 3ee4f94..cd9f64a 100644
--- a/gcc/elna-generic.cc
+++ b/gcc/elna-generic.cc
@@ -38,112 +38,41 @@ namespace elna
 {
 namespace gcc
 {
-    declaration_visitor::declaration_visitor(std::shared_ptr<symbol_table> symbol_table)
-        : symbols(symbol_table)
+    static tree get_inner_alias(std::shared_ptr<symbol_table> symbol_table, const boot::type& type)
     {
-        this->symbols->enter("Int", elna_int_type_node);
-        this->symbols->enter("Word", elna_word_type_node);
-        this->symbols->enter("Char", elna_char_type_node);
-        this->symbols->enter("Bool", elna_bool_type_node);
-        this->symbols->enter("Byte", elna_byte_type_node);
-        this->symbols->enter("Float", elna_float_type_node);
-        this->symbols->enter("String", elna_string_type_node);
-    }
-
-    tree declaration_visitor::get_inner_alias(const boot::alias_type& t)
-    {
-        if (t.reference == nullptr)
+        if (auto reference = type.get<boot::primitive_type>())
         {
-            return NULL_TREE;
+            return symbol_table->lookup(reference->identifier);
         }
-        else if (auto reference = t.reference->is_primitive())
-        {
-            return this->symbols->lookup(reference->identifier);
-        }
-        else if (auto reference = t.reference->is_alias())
-        {
-            return get_inner_alias(*reference);
-        }
-        else if (auto reference = t.reference->is_record())
+        else if (auto reference = type.get<boot::record_type>())
         {
             return make_node(RECORD_TYPE);
         }
-        else if (auto reference = t.reference->is_union())
+        else if (auto reference = type.get<boot::union_type>())
         {
             return make_node(UNION_TYPE);
         }
-        return NULL_TREE;
+        else if (auto reference = type.get<boot::pointer_type>())
+        {
+            return build_pointer_type_for_mode(get_inner_alias(symbol_table, reference->base), VOIDmode, true);
+        }
+        else if (auto reference = type.get<boot::alias_type>())
+        {
+            return get_inner_alias(symbol_table, reference->reference);
+        }
+        return error_mark_node;
     }
 
-    boot::type *declaration_visitor::build_type(boot::type_expression *type_expression)
+    void do_semantic_analysis(std::shared_ptr<symbol_table> symbols, std::unique_ptr<boot::program>& ast)
     {
-        if (auto alias_node = type_expression->is_primitive())
-        {
-            return this->unresolved.at(alias_node->name);
-        }
-        else if (auto alias_node = type_expression->is_record())
-        {
-            return build_record(alias_node.get());
-        }
-        else if (auto alias_node = type_expression->is_union())
-        {
-            return build_union(alias_node.get());
-        }
-        return nullptr;
-    }
+        boot::declaration_visitor declaration_visitor;
 
-    boot::record_type *declaration_visitor::build_record(boot::record_type_expression *type_expression)
-    {
-        return new boot::record_type();
-    }
-
-    boot::union_type *declaration_visitor::build_union(boot::union_type_expression *type_expression)
-    {
-        return new boot::union_type();
-    }
-
-    void declaration_visitor::visit(boot::program *program)
-    {
-        for (boot::type_definition *const type : program->types)
+        declaration_visitor.visit(ast.get());
+        for (auto unresolved : declaration_visitor.unresolved)
         {
-            type->accept(this);
+            auto inner_alias = elna::gcc::get_inner_alias(symbols, boot::type(unresolved.second));
+            symbols->enter(unresolved.first, inner_alias);
         }
-        for (boot::type_definition *const type : program->types)
-        {
-            auto unresolved_declaration = this->unresolved.at(type->identifier);
-
-            if (auto alias_node = type->body().is_primitive())
-            {
-                auto unresolved_alias = this->unresolved.find(alias_node->name);
-
-                if (unresolved_alias != this->unresolved.end())
-                {
-                    unresolved_declaration->reference = unresolved_alias->second;
-                }
-                else
-                {
-                    unresolved_declaration->reference = new boot::primitive_type(alias_node->name);
-                }
-            }
-            else if (auto alias_node = type->body().is_record())
-            {
-                unresolved_declaration->reference = build_record(alias_node.get());
-            }
-            else if (auto alias_node = type->body().is_union())
-            {
-                unresolved_declaration->reference = build_union(alias_node.get());
-            }
-        }
-        for (auto unresolved : this->unresolved)
-        {
-            auto inner_alias = get_inner_alias(*unresolved.second);
-            this->symbols->enter(unresolved.first, inner_alias);
-        }
-    }
-
-    void declaration_visitor::visit(boot::type_definition *definition)
-    {
-        this->unresolved.insert({ definition->identifier, new boot::alias_type() });
     }
 
     generic_visitor::generic_visitor(std::shared_ptr<symbol_table> symbol_table)
diff --git a/gcc/elna1.cc b/gcc/elna1.cc
index 5713719..07d8a31 100644
--- a/gcc/elna1.cc
+++ b/gcc/elna1.cc
@@ -90,10 +90,17 @@ static void elna_parse_file(const char *filename)
     {
         std::shared_ptr<elna::gcc::symbol_table> symbol_table = std::make_shared<elna::gcc::symbol_table>();
 
-        elna::gcc::declaration_visitor declaration_visitor{ symbol_table };
+        symbol_table->enter("Int", elna_int_type_node);
+        symbol_table->enter("Word", elna_word_type_node);
+        symbol_table->enter("Char", elna_char_type_node);
+        symbol_table->enter("Bool", elna_bool_type_node);
+        symbol_table->enter("Byte", elna_byte_type_node);
+        symbol_table->enter("Float", elna_float_type_node);
+        symbol_table->enter("String", elna_string_type_node);
+
+        elna::gcc::do_semantic_analysis(symbol_table, driver.tree);
         elna::gcc::generic_visitor generic_visitor{ symbol_table };
 
-        declaration_visitor.visit(driver.tree.get());
         generic_visitor.visit(driver.tree.get());
     }
     linemap_add(line_table, LC_LEAVE, 0, NULL, 0);
diff --git a/include/elna/boot/ast.h b/include/elna/boot/ast.h
index 0727a39..6c32a54 100644
--- a/include/elna/boot/ast.h
+++ b/include/elna/boot/ast.h
@@ -294,15 +294,14 @@ namespace boot
         type_expression& base();
     };
 
-    using field_t = std::pair<std::string, std::shared_ptr<type_expression>>;
-    using fields_t = std::vector<field_t>;
+    using field_declaration = std::pair<std::string, std::shared_ptr<type_expression>>;
 
     class record_type_expression : public type_expression
     {
     public:
-        fields_t fields;
+        const std::vector<field_declaration> fields;
 
-        record_type_expression(const struct position position, fields_t&& fields);
+        record_type_expression(const struct position position, std::vector<field_declaration>&& fields);
 
         void accept(parser_visitor *visitor);
         std::shared_ptr<record_type_expression> is_record() override;
@@ -311,9 +310,9 @@ namespace boot
     class union_type_expression : public type_expression
     {
     public:
-        fields_t fields;
+        std::vector<field_declaration> fields;
 
-        union_type_expression(const struct position position, fields_t&& fields);
+        union_type_expression(const struct position position, std::vector<field_declaration>&& fields);
 
         void accept(parser_visitor *visitor);
         std::shared_ptr<union_type_expression> is_union() override;
diff --git a/include/elna/boot/semantic.h b/include/elna/boot/semantic.h
index de6030a..fc343b2 100644
--- a/include/elna/boot/semantic.h
+++ b/include/elna/boot/semantic.h
@@ -17,59 +17,105 @@ along with GCC; see the file COPYING3.  If not see
 
 #include <string>
 #include <vector>
+#include <unordered_map>
+
+#include "elna/boot/ast.h"
 
 namespace elna
 {
 namespace boot
 {
     class alias_type;
+    class primitive_type;
     class record_type;
     class union_type;
-    class primitive_type;
+    class pointer_type;
 
     class type
     {
-    public:
-        virtual alias_type *is_alias();
-        virtual primitive_type *is_primitive();
-        virtual record_type *is_record();
-        virtual union_type *is_union();
+        enum class type_tag
+        {
+            empty,
+            alias,
+            primitive,
+            record,
+            _union,
+            pointer,
+        };
+        union
+        {
+            nullptr_t empty;
+            alias_type *alias;
+            primitive_type *primitive;
+            record_type *record;
+            union_type *_union;
+            pointer_type *pointer;
+        } payload{ .empty = nullptr };
 
-        virtual ~type() = 0;
+        type_tag tag{ type_tag::empty };
+
+    public:
+        type() = default;
+        explicit type(alias_type *alias);
+        explicit type(primitive_type *primitive);
+        explicit type(record_type *record);
+        explicit type(union_type *_union);
+        explicit type(pointer_type *pointer);
+
+        template<typename T>
+        T *const get() const;
+
+        bool empty() const;
     };
 
-    class alias_type : public type
+    struct alias_type
     {
-    public:
-        alias_type *is_alias() override;
-
-        type *reference{ nullptr };
+        type reference;
     };
 
-    class primitive_type : public type
+    struct pointer_type
     {
-    public:
-        std::string identifier;
+        const type base;
 
-        primitive_type(const std::string& identifier);
-
-        primitive_type *is_primitive() override;
+        explicit pointer_type(type base);
     };
 
-    class record_type : public type
+    struct primitive_type
     {
-    public:
-        std::vector<std::pair<std::string, type *>> fields;
+        const std::string identifier;
 
-        record_type *is_record() override;
+        explicit primitive_type(const std::string& identifier);
     };
 
-    class union_type : public type
-    {
-    public:
-        std::vector<std::pair<std::string, type *>> fields;
+    using type_field = typename std::pair<std::string, type>;
 
-        union_type *is_union() override;
+    struct record_type
+    {
+        std::vector<type_field> fields;
+    };
+
+    struct union_type
+    {
+        std::vector<type_field> fields;
+    };
+
+    class declaration_visitor final : public empty_visitor
+    {
+        type current_type;
+
+    public:
+        std::unordered_map<std::string, alias_type *> unresolved;
+
+        declaration_visitor() = default;
+
+        void visit(primitive_type_expression *type_expression) override;
+        void visit(array_type_expression *type_expression) override;
+        void visit(pointer_type_expression *type_expression) override;
+        void visit(program *program) override;
+        void visit(type_definition *definition) override;
+        void visit(record_type_expression *type_expression) override;
+        void visit(union_type_expression *type_expression) override;
+        void visit(procedure_type_expression *type_expression) override;
     };
 }
 }
diff --git a/include/elna/gcc/elna-generic.h b/include/elna/gcc/elna-generic.h
index 4f4c635..2dfb2d9 100644
--- a/include/elna/gcc/elna-generic.h
+++ b/include/elna/gcc/elna-generic.h
@@ -28,29 +28,13 @@ along with GCC; see the file COPYING3.  If not see
 #include "tree.h"
 #include "tree-iterator.h"
 
-#include <unordered_map>
 #include <string>
 
 namespace elna
 {
 namespace gcc
 {
-    class declaration_visitor final : public boot::empty_visitor
-    {
-        std::shared_ptr<symbol_table> symbols;
-        std::unordered_map<std::string, boot::alias_type *> unresolved;
-
-        boot::type *build_type(boot::type_expression *type_expression);
-        boot::record_type *build_record(boot::record_type_expression *type_expression);
-        boot::union_type *build_union(boot::union_type_expression *type_expression);
-        tree get_inner_alias(const boot::alias_type& t);
-
-    public:
-        declaration_visitor(std::shared_ptr<symbol_table> symbol_table);
-
-        void visit(boot::program *program) override;
-        void visit(boot::type_definition *definition) override;
-    };
+    void do_semantic_analysis(std::shared_ptr<symbol_table> symbols, std::unique_ptr<boot::program>& ast);
 
     class generic_visitor final : public boot::empty_visitor
     {