add a new method to insert a new value in an array at specific index. (#949)
* add a new method to insert a new value in an array at specific index.
* update: index > length, return false;
* fix clang-format
diff --git a/include/json/value.h b/include/json/value.h
index e3c3d2b..5c10163 100644
--- a/include/json/value.h
+++ b/include/json/value.h
@@ -464,6 +464,8 @@
/// Equivalent to jsonvalue[jsonvalue.size()] = value;
Value& append(const Value& value);
Value& append(Value&& value);
+ /// \brief Insert value in array at specific index
+ bool insert(ArrayIndex index, Value newValue);
/// Access an object value by name, create a null member if it does not exist.
/// \note Because of our implementation, keys are limited to 2^30 -1 chars.
diff --git a/src/lib_json/json_value.cpp b/src/lib_json/json_value.cpp
index 9518ab8..00d28f7 100644
--- a/src/lib_json/json_value.cpp
+++ b/src/lib_json/json_value.cpp
@@ -1148,6 +1148,7 @@
#endif
Value& Value::append(const Value& value) { return append(Value(value)); }
+
Value& Value::append(Value&& value) {
JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
"in Json::Value::append: requires arrayValue");
@@ -1157,6 +1158,21 @@
return this->value_.map_->emplace(size(), std::move(value)).first->second;
}
+bool Value::insert(ArrayIndex index, Value newValue) {
+ JSON_ASSERT_MESSAGE(type() == nullValue || type() == arrayValue,
+ "in Json::Value::insert: requires arrayValue");
+ ArrayIndex length = size();
+ if (index > length) {
+ return false;
+ } else {
+ for (ArrayIndex i = length; i > index; i--) {
+ (*this)[i] = std::move((*this)[i - 1]);
+ }
+ (*this)[index] = std::move(newValue);
+ return true;
+ }
+}
+
Value Value::get(char const* begin, char const* end,
Value const& defaultValue) const {
Value const* found = find(begin, end);
diff --git a/src/test_lib_json/main.cpp b/src/test_lib_json/main.cpp
index c79ad1e..f32a11f 100644
--- a/src/test_lib_json/main.cpp
+++ b/src/test_lib_json/main.cpp
@@ -327,6 +327,63 @@
// JSONTEST_ASSERT_EQUAL(5, root["array"].size());
}
+JSONTEST_FIXTURE_LOCAL(ValueTest, arrayInsertAtRandomIndex) {
+ Json::Value array;
+ const Json::Value str0("index2");
+ const Json::Value str1("index3");
+ array.append("index0"); // append rvalue
+ array.append("index1");
+ array.append(str0); // append lvalue
+
+ std::vector<Json::Value*> vec; // storage value address for checking
+ for (int i = 0; i < 3; i++) {
+ vec.push_back(&array[i]);
+ }
+ JSONTEST_ASSERT_EQUAL(Json::Value("index0"), array[0]); // check append
+ JSONTEST_ASSERT_EQUAL(Json::Value("index1"), array[1]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index2"), array[2]);
+
+ // insert lvalue at the head
+ JSONTEST_ASSERT(array.insert(0, str1));
+ JSONTEST_ASSERT_EQUAL(Json::Value("index3"), array[0]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index0"), array[1]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index1"), array[2]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index2"), array[3]);
+ // checking address
+ for (int i = 0; i < 3; i++) {
+ JSONTEST_ASSERT_EQUAL(vec[i], &array[i]);
+ }
+ vec.push_back(&array[3]);
+ // insert rvalue at middle
+ JSONTEST_ASSERT(array.insert(2, "index4"));
+ JSONTEST_ASSERT_EQUAL(Json::Value("index3"), array[0]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index0"), array[1]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index4"), array[2]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index1"), array[3]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index2"), array[4]);
+ // checking address
+ for (int i = 0; i < 4; i++) {
+ JSONTEST_ASSERT_EQUAL(vec[i], &array[i]);
+ }
+ vec.push_back(&array[4]);
+ // insert rvalue at the tail
+ Json::Value index5("index5");
+ JSONTEST_ASSERT(array.insert(5, std::move(index5)));
+ JSONTEST_ASSERT_EQUAL(Json::Value("index3"), array[0]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index0"), array[1]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index4"), array[2]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index1"), array[3]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index2"), array[4]);
+ JSONTEST_ASSERT_EQUAL(Json::Value("index5"), array[5]);
+ // checking address
+ for (int i = 0; i < 5; i++) {
+ JSONTEST_ASSERT_EQUAL(vec[i], &array[i]);
+ }
+ vec.push_back(&array[5]);
+ // beyond max array size, it should not be allowed to insert into its tail
+ JSONTEST_ASSERT(!array.insert(10, "index10"));
+}
+
JSONTEST_FIXTURE_LOCAL(ValueTest, null) {
JSONTEST_ASSERT_EQUAL(Json::nullValue, null_.type());