change in literals, literal types

include/nodes/basic_nodes.hpp

@@ -79,6 +79,14 @@ protected:
 struct unit {};
 struct null {};
 
+struct unicode_string {
+  std::string str;
+};
+
+struct unicode {
+  std::string ch;
+};
+
 class Literal : public Node {
 public:
   template <typename T>
@@ -103,7 +111,9 @@ public:
   auto get_any() const { return &value_; }
 
 private:
-  std::variant<double, long long, std::string, char, bool, unit, null> value_;
+  std::variant<float, double, int32_t, int64_t, size_t, std::string,
+               unicode_string, char, unicode, bool, unit, null>
+      value_;
 };
 
 class Identifier : public Node {