Unify the build_type function

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;
     }
 }
 }