From 208aeac98cdd1e53b0d9d95bd8779008bdf039a2 Mon Sep 17 00:00:00 2001
From: Xie Han <63350856@qq.com>
Date: Fri, 22 Dec 2023 19:21:02 +0800
Subject: [PATCH] feat: use JSON type: -1 as placeholder.

---
 Json.cc               | 12 ++++++------
 Json.h                | 12 ++++++------
 test/json_obj_test.cc |  4 ++--
 3 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/Json.cc b/Json.cc
index 2505a7a..d306d32 100644
--- a/Json.cc
+++ b/Json.cc
@@ -52,7 +52,7 @@ json_value_t* json_value_copy(const json_value_t* val)
 
 // ------------------------ Constructor -------------------------
 Json::Json()
-    : node_(json_value_create(JSON_VALUE_NULL)), parent_(nullptr),
+    : node_(json_value_create(-1)), parent_(nullptr),
       allocated_(true)
 {
 }
@@ -231,7 +231,7 @@ std::string Json::dump(int spaces) const
 
 Json Json::operator[](const char* key)
 {
-    if (is_null() && is_root())
+    if (is_placeholder() && is_root())
     {
         // todo : need is_root here?
         to_object();
@@ -369,7 +369,7 @@ bool Json::can_obj_push_back()
     {
         return true;
     }
-    if (is_root() && is_null())
+    if (is_root() && is_placeholder())
     {
         to_object();
     }
@@ -585,7 +585,7 @@ void Json::normal_push_back(const std::string& key, const Json& val)
 
 bool Json::can_arr_push_back()
 {
-    if (is_root() && is_null())
+    if (is_root() && is_placeholder())
     {
         to_array();
     }
@@ -786,7 +786,7 @@ void Json::clear()
 
 bool Json::to_object()
 {
-    if (!allocated_ || !is_null())
+    if (!allocated_ || !is_placeholder())
     {
         // watcher and non-null type can't change type
         return false;
@@ -799,7 +799,7 @@ bool Json::to_object()
 
 bool Json::to_array()
 {
-    if (!allocated_ || !is_null())
+    if (!allocated_ || !is_placeholder())
     {
         // watcher and non-null type can't change type
         return false;
diff --git a/Json.h b/Json.h
index 14a06ae..060261b 100644
--- a/Json.h
+++ b/Json.h
@@ -175,6 +175,12 @@ class Json
         return type() == JSON_VALUE_STRING;
     }
 
+    // can convert to any type, just like a placeholder
+    bool is_placeholder() const
+    {
+        return json_value_type(node_) == -1;
+    }
+
     bool is_valid() const
     {
         return node_ != nullptr;
@@ -684,12 +690,6 @@ class Json
 
     bool can_arr_push_back();
 
-    // can convert to any type, just like a placeholder
-    bool is_placeholder() const
-    {
-        return is_null() && parent_ != nullptr;
-    }
-
     void destroy_node(json_value_t** node)
     {
         if (allocated_)
diff --git a/test/json_obj_test.cc b/test/json_obj_test.cc
index a197a36..84c0c8f 100644
--- a/test/json_obj_test.cc
+++ b/test/json_obj_test.cc
@@ -19,9 +19,9 @@ TEST(ObjTest, empty_obj)
 TEST(ObjTest, one_level)
 {
     Json data;
-    EXPECT_TRUE(data.is_null());
+    EXPECT_TRUE(data.is_placeholder());
     Json data_tmp = data["test"];
-    EXPECT_TRUE(data_tmp.is_null());
+    EXPECT_TRUE(data_tmp.is_placeholder());
     data["test"] = 1.0;
     EXPECT_EQ(data.type(), JSON_VALUE_OBJECT);
     EXPECT_TRUE(data.is_object());