keep insertion order in merge and clone

README.md

@@ -29,7 +29,7 @@ The C++ implementation of Hjson is based on [hjson-go](https://github.com/hjson/
 
 # Compiling
 
-The easiest way to use hjson-cpp is to simply include all of the files from the folders `src` and `include` into you own project. The only requirement is that your compiler fully supports C++11.
+The easiest way to use hjson-cpp is to simply include all of the files from the folders `src` and `include` into your own project. The only requirement is that your compiler fully supports C++11.
 
 GCC 4.8 has the C++11 headers for regex, but unfortunately not a working implementation, so for GCC at least version 4.9 is required.
 
@@ -247,6 +247,8 @@ assert(val1.key(1) == "zeta");
 assert(val1[0] == 2);
 ```
 
+The insertion order is kept when cloning or merging *Hjson::Value* maps.
+
 ### Performance
 
 Hjson is not much optimized for speed. But if you require fast(-ish) execution, escpecially in a multithreaded application, you can experiment with different values for the Cmake option `HJSON_NUMBER_PARSER`. The default value `StringStream` uses C++ string streams with the locale `classic` imbued to ensure that dots are used as decimal separators rather than commas.

src/hjson_value.cpp

@@ -741,8 +741,8 @@ Value Value::clone() const {
   case ValueImpl::IMPL_MAP:
     {
       Value ret;
-      for (auto it = begin(); it != end(); ++it) {
-        ret[it->first] = it->second.clone();
+      for (int index = 0; index < size(); ++index) {
+        ret[key(index)] = operator[](index).clone();
       }
       return ret;
     }
@@ -1209,13 +1209,17 @@ Value Merge(const Value base, const Value ext) {
   if (!ext.defined()) {
     merged = base.clone();
   } else if (base.type() == Value::MAP && ext.type() == Value::MAP) {
-    for (auto it = ext.begin(); it != ext.end(); ++it) {
-      merged[it->first] = Merge(base[it->first], it->second);
+    for (int index = 0; index < base.size(); ++index) {
+      if (ext[base.key(index)].defined()) {
+        merged[base.key(index)] = Merge(base[index], ext[base.key(index)]);
+      } else {
+        merged[base.key(index)] = base[index].clone();
+      }
     }
 
-    for (auto it = base.begin(); it != base.end(); ++it) {
-      if (!merged[it->first].defined()) {
-        merged[it->first] = it->second.clone();
+    for (int index = 0; index < ext.size(); ++index) {
+      if (!merged[ext.key(index)].defined()) {
+        merged[ext.key(index)] = ext[index].clone();
       }
     }
   } else {

test/test_value.cpp

@@ -650,8 +650,7 @@ void test_value() {
   }
 
   {
-    Hjson::Value base = Hjson::Unmarshal(R"(
-{
+    std::string baseStr = R"({
   debug: false
   rect: {
     x: 0
@@ -672,8 +671,8 @@ void test_value() {
     width: 200
     height: 200
   }
-}
-)");
+})";
+    Hjson::Value base = Hjson::Unmarshal(baseStr);
 
     Hjson::Value ext = Hjson::Unmarshal(R"(
 {
@@ -704,5 +703,14 @@ void test_value() {
     assert(merged["scale"] == 3);
     assert(merged["window"]["y"] == 37);
     assert(merged["otherWindow"]["x"] == 17);
+    // The insertion order must have been kept in the merge.
+    assert(merged.key(1) == "rect");
+    // The insertion order must have been kept in the clone.
+    auto baseClone = base.clone();
+    auto options = Hjson::DefaultOptions();
+    options.bracesSameLine = true;
+    options.preserveInsertionOrder = true;
+    auto baseCloneStr = Hjson::MarshalWithOptions(baseClone, options);
+    assert(baseCloneStr == baseStr);
   }
 }