Redesigned JsonVariant to leverage converting constructors instead of assignment operators

src/Internals/JsonParser.cpp

@@ -38,25 +38,27 @@ bool JsonParser::skip(const char *wordToSkip) {
   return *charToSkip == '\0';
 }
 
-void JsonParser::parseAnythingTo(JsonVariant &destination) {
-  if (_nestingLimit == 0) return;
+bool JsonParser::parseAnythingTo(JsonVariant *destination) {
+  if (_nestingLimit == 0) return false;
   _nestingLimit--;
+  bool success = parseAnythingToUnsafe(destination);
+  _nestingLimit++;
+  return success;
+}
 
+inline bool JsonParser::parseAnythingToUnsafe(JsonVariant *destination) {
   skipSpaces();
 
   switch (*_ptr) {
     case '[':
-      destination = parseArray();
-      break;
+      return parseArrayTo(destination);
 
     case '{':
-      destination = parseObject();
-      break;
+      return parseObjectTo(destination);
 
     case 't':
     case 'f':
-      parseBooleanTo(destination);
-      break;
+      return parseBooleanTo(destination);
 
     case '-':
     case '.':
@@ -70,20 +72,14 @@ void JsonParser::parseAnythingTo(JsonVariant &destination) {
     case '7':
     case '8':
     case '9':
-      parseNumberTo(destination);
-      break;
+      return parseNumberTo(destination);
 
     case 'n':
-      parseNullTo(destination);
-      break;
+      return parseNullTo(destination);
 
-    case '\'':
-    case '\"':
-      destination = parseString();
-      break;
+    default:
+      return parseStringTo(destination);
   }
-
-  _nestingLimit++;
 }
 
 JsonArray &JsonParser::parseArray() {
@@ -97,9 +93,9 @@ JsonArray &JsonParser::parseArray() {
   // Read each value
   for (;;) {
     // 1 - Parse value
-    JsonVariant &value = array.add();
-    parseAnythingTo(value);
-    if (!value.success()) goto ERROR_INVALID_VALUE;
+    JsonVariant value;
+    if (!parseAnythingTo(&value)) goto ERROR_INVALID_VALUE;
+    if (!array.add(value)) goto ERROR_NO_MEMORY;
 
     // 2 - More values?
     if (skip(']')) goto SUCCES_NON_EMPTY_ARRAY;
@@ -113,9 +109,18 @@ SUCCES_NON_EMPTY_ARRAY:
 ERROR_INVALID_VALUE:
 ERROR_MISSING_BRACKET:
 ERROR_MISSING_COMMA:
+ERROR_NO_MEMORY:
   return JsonArray::invalid();
 }
 
+bool JsonParser::parseArrayTo(JsonVariant *destination) {
+  JsonArray &array = parseArray();
+  if (!array.success()) return false;
+
+  *destination = array;
+  return true;
+}
+
 JsonObject &JsonParser::parseObject() {
   // Create an empty object
   JsonObject &object = _buffer->createObject();
@@ -132,9 +137,9 @@ JsonObject &JsonParser::parseObject() {
     if (!skip(':')) goto ERROR_MISSING_COLON;
 
     // 2 - Parse value
-    JsonVariant &value = object.add(key);
-    parseAnythingTo(value);
-    if (!value.success()) goto ERROR_INVALID_VALUE;
+    JsonVariant value;
+    if (!parseAnythingTo(&value)) goto ERROR_INVALID_VALUE;
+    if (!object.set(key, value)) goto ERROR_NO_MEMORY;
 
     // 3 - More keys/values?
     if (skip('}')) goto SUCCESS_NON_EMPTY_OBJECT;
@@ -150,19 +155,31 @@ ERROR_INVALID_VALUE:
 ERROR_MISSING_BRACE:
 ERROR_MISSING_COLON:
 ERROR_MISSING_COMMA:
+ERROR_NO_MEMORY:
   return JsonObject::invalid();
 }
 
-void JsonParser::parseBooleanTo(JsonVariant &destination) {
-  if (skip("true"))
-    destination = true;
-  else if (skip("false"))
-    destination = false;
-  else
-    destination = JsonVariant::invalid();
+bool JsonParser::parseObjectTo(JsonVariant *destination) {
+  JsonObject &object = parseObject();
+  if (!object.success()) return false;
+
+  *destination = object;
+  return true;
 }
 
-void JsonParser::parseNumberTo(JsonVariant &destination) {
+bool JsonParser::parseBooleanTo(JsonVariant *destination) {
+  if (skip("true")) {
+    *destination = true;
+    return true;
+  } else if (skip("false")) {
+    *destination = false;
+    return true;
+  } else {
+    return false;
+  }
+}
+
+bool JsonParser::parseNumberTo(JsonVariant *destination) {
   char *endOfLong;
   long longValue = strtol(_ptr, &endOfLong, 10);
   char stopChar = *endOfLong;
@@ -176,22 +193,28 @@ void JsonParser::parseNumberTo(JsonVariant &destination) {
     // Count the decimal digits
     uint8_t decimals = static_cast<uint8_t>(_ptr - endOfLong - 1);
     // Set the variant as a double
-    destination.set(doubleValue, decimals);
+    *destination = JsonVariant(doubleValue, decimals);
   } else {
     // No => set the variant as a long
     _ptr = endOfLong;
-    destination = longValue;
+    *destination = longValue;
   }
+  return true;
 }
 
-void JsonParser::parseNullTo(JsonVariant &destination) {
+bool JsonParser::parseNullTo(JsonVariant *destination) {
   const char *NULL_STRING = NULL;
-  if (skip("null"))
-    destination = NULL_STRING;
-  else
-    destination = JsonVariant::invalid();
+  if (!skip("null")) return false;
+  *destination = NULL_STRING;
+  return true;
 }
 
 const char *JsonParser::parseString() {
   return QuotedString::extractFrom(_ptr, &_ptr);
 }
+
+bool JsonParser::parseStringTo(JsonVariant *destination) {
+  const char *value = parseString();
+  *destination = value;
+  return value != NULL;
+}

src/Internals/List.cpp

@@ -13,8 +13,8 @@ using namespace ArduinoJson;
 using namespace ArduinoJson::Internals;
 
 template <typename T>
-int List<T>::size() const {
-  int nodeCount = 0;
+size_t List<T>::size() const {
+  size_t nodeCount = 0;
   for (node_type *node = _firstNode; node; node = node->next) nodeCount++;
   return nodeCount;
 }

src/Internals/Prettyfier.cpp

@@ -33,7 +33,7 @@ inline size_t Prettyfier::handleMarkupChar(uint8_t c) {
       return handleBlockClose(c);
 
     case ':':
-      return handleColumn();
+      return handleColon();
 
     case ',':
       return handleComma();
@@ -54,7 +54,7 @@ inline size_t Prettyfier::handleBlockClose(uint8_t c) {
   return unindentIfNeeded() + _sink.write(c);
 }
 
-inline size_t Prettyfier::handleColumn() {
+inline size_t Prettyfier::handleColon() {
   return _sink.write(':') + _sink.write(' ');
 }