Add Object.to_string method

cclox_src/scanner/object.cc

@@ -1,6 +1,26 @@
 #include "object.hh"
 #include <string>
 
+std::string Object::to_string() {
+  switch (type) {
+    case ObjectType::NIL:
+      return "nil";
+    case ObjectType::BOOL: {
+      bool val = std::get<bool>(value);
+      return (val ? "true" : "false");
+    }
+    case ObjectType::IDENTIFIER:
+    case ObjectType::STRING_LIT: {
+      std::string val = std::get<std::string>(value);
+      return val;
+    }
+    case ObjectType::NUMBER: {
+      double val = std::get<double>(value);
+      return std::to_string(val);
+    }
+  }
+}
+
 std::ostream &operator<<(std::ostream &os, const ObjectType &type) {
   switch (type) {
     case ObjectType::NIL:

cclox_src/scanner/object.hh

@@ -29,6 +29,7 @@ struct Object {
         ObjectType::STRING_LIT
       },
       value{std::move(value)} {};
+  std::string to_string();
 
   ObjectType type;
   std::variant<std::monostate, std::string, double, bool> value;