Json: implement structural == for JsonObject/JsonValue/JsonArray

Common/Cpp/Json/JsonArray.h

@@ -26,6 +26,24 @@ class JsonArray{
 public:
     JsonArray clone() const;
 
+    //  Structurally compare two arrays.
+    friend bool operator==(const JsonArray& x, const JsonArray& y){
+        if (x.m_data.size() != y.m_data.size()){
+            return false;
+        }
+        auto itx = x.m_data.cbegin();
+        auto ity = y.m_data.cbegin();
+        for (; itx != x.m_data.cend(); ++itx, ++ity){
+            if (!(*itx == *ity)){
+                return false;
+            }
+        }
+        return true;
+    }
+    friend bool operator!=(const JsonArray& x, const JsonArray& y){
+        return !(x == y);
+    }
+
 public:
     std::string dump(int indent = 4) const;
     void dump(const std::string& filename, int indent = 4) const;

Common/Cpp/Json/JsonObject.h

@@ -19,9 +19,19 @@ class JsonObject{
     JsonObject(JsonObject&& x) = default;
     JsonObject& operator=(JsonObject&& x) = default;
 
-    //  TODO: implement == properly. For JsonValue as well.
+    //  Structurally compare two objects.
     friend bool operator==(const JsonObject& x, const JsonObject& y){
-        return x.dump() == y.dump();
+        if (x.m_data.size() != y.m_data.size()){
+            return false;
+        }
+        auto itx = x.m_data.cbegin();
+        auto ity = y.m_data.cbegin();
+        for (; itx != x.m_data.cend(); ++itx, ++ity){
+            if (itx->first != ity->first || !(itx->second == ity->second)){
+                return false;
+            }
+        }
+        return true;
     }
     friend bool operator!=(const JsonObject& x, const JsonObject& y){
         return !(x == y);

Common/Cpp/Json/JsonValue.cpp

@@ -367,6 +367,36 @@ bool JsonValue::read_string(std::string& value) const{
 
 
 
+//  Equality.
+
+bool operator==(const JsonValue& x, const JsonValue& y){
+    if (x.m_type != y.m_type){
+        return false;
+    }
+    switch (x.m_type){
+    case JsonType::EMPTY:
+        return true;
+    case JsonType::BOOLEAN:
+        return x.u.m_bool == y.u.m_bool;
+    case JsonType::INTEGER:
+        return x.u.m_integer == y.u.m_integer;
+    case JsonType::FLOAT:
+        return x.u.m_float == y.u.m_float;
+    case JsonType::STRING:
+        return *x.u.m_string == *y.u.m_string;
+    case JsonType::ARRAY:
+        return *x.u.m_array == *y.u.m_array;
+    case JsonType::OBJECT:
+        return *x.u.m_object == *y.u.m_object;
+    }
+    return false;
+}
+bool operator!=(const JsonValue& x, const JsonValue& y){
+    return !(x == y);
+}
+
+
+
 JsonValue parse_json(const std::string& str){
     return from_nlohmann(nlohmann::json::parse(str, nullptr, false));
 }

Common/Cpp/Json/JsonValue.h

@@ -72,6 +72,11 @@ class JsonValue{
 public:
     JsonValue clone() const;
 
+    //  Structurally compare two values.
+    //  (Defined in JsonValue.cpp; requires the complete types of JsonArray/JsonObject.)
+    friend bool operator==(const JsonValue& x, const JsonValue& y);
+    friend bool operator!=(const JsonValue& x, const JsonValue& y);
+
 public:
     JsonValue() = default;
     JsonValue(bool x);