Unify the build_type function

boot/semantic.cc

@@ -69,5 +69,66 @@ namespace boot
     {
         return this;
     }
+
+    void declaration_visitor::visit(program *program)
+    {
+        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);
+        }
+    }
+
+    void declaration_visitor::visit(type_definition *definition)
+    {
+        auto unresolved_declaration = this->unresolved.at(definition->identifier);
+
+        definition->body().accept(this);
+
+        if (this->current_type != nullptr)
+        {
+            unresolved_declaration->reference = this->current_type;
+        }
+        this->current_type = nullptr;
+    }
+
+    void declaration_visitor::visit(primitive_type_expression *type)
+    {
+        auto unresolved_alias = this->unresolved.find(type->name);
+
+        if (unresolved_alias != this->unresolved.end())
+        {
+            this->current_type = unresolved_alias->second;
+        }
+        else
+        {
+            this->current_type = new primitive_type(type->name);
+        }
+    }
+
+    void declaration_visitor::visit(array_type_expression *type)
+    {
+    }
+
+    void declaration_visitor::visit(pointer_type_expression *type)
+    {
+    }
+
+    void declaration_visitor::visit(record_type_expression *type)
+    {
+        this->current_type = new record_type();
+    }
+
+    void declaration_visitor::visit(union_type_expression *type)
+    {
+        this->current_type = new union_type();
+    }
+
+    void declaration_visitor::visit(procedure_type_expression *type)
+    {
+    }
 }
 }