Merge pull request #127 from cdunn2001/removeIndex

`Value::removeIndex()`

See issue #28.

Author: cdunn2001

include/json/value.h

@@ -395,6 +395,14 @@ Json::Value obj_value(Json::objectValue); // {}
   Value removeMember(const char* key);
   /// Same as removeMember(const char*)
   Value removeMember(const std::string& key);
+  /** \brief Remove the indexed array element.
+
+      O(n) expensive operations.
+      Update 'removed' iff removed.
+      (This is a better pattern than removeMember().)
+      \return true iff removed (no exceptions)
+  */
+  bool removeIndex(ArrayIndex i, Value* removed);
 
   /// Return true if the object has a member named key.
   bool isMember(const char* key) const;

src/lib_json/json_value.cpp

@@ -1018,6 +1018,34 @@ Value Value::removeMember(const std::string& key) {
   return removeMember(key.c_str());
 }
 
+bool Value::removeIndex(ArrayIndex index, Value* removed) {
+  if (type_ != arrayValue) {
+    return false;
+  }
+#ifdef JSON_VALUE_USE_INTERNAL_MAP
+  JSON_FAIL_MESSAGE("removeIndex is not implemented for ValueInternalArray.");
+  return false;
+#else
+  CZString key(index);
+  ObjectValues::iterator it = value_.map_->find(key);
+  if (it == value_.map_->end()) {
+    return false;
+  }
+  *removed = it->second;
+  ArrayIndex oldSize = size();
+  // shift left all items left, into the place of the "removed"
+  for (ArrayIndex i = index; i < (oldSize - 1); ++i){
+    CZString key(i);
+    (*value_.map_)[key] = (*this)[i + 1];
+  }
+  // erase the last one ("leftover")
+  CZString keyLast(oldSize - 1);
+  ObjectValues::iterator itLast = value_.map_->find(keyLast);
+  value_.map_->erase(itLast);
+  return true;
+#endif
+}
+
 #ifdef JSON_USE_CPPTL
 Value Value::get(const CppTL::ConstString& key,
                  const Value& defaultValue) const {

src/test_lib_json/main.cpp

@@ -198,6 +198,14 @@ JSONTEST_FIXTURE(ValueTest, objects) {
 
   object1_["some other id"] = "foo";
   JSONTEST_ASSERT_EQUAL(Json::Value("foo"), object1_["some other id"]);
+  JSONTEST_ASSERT_EQUAL(Json::Value("foo"), object1_["some other id"]);
+
+  // Remove.
+  Json::Value got;
+  got = object1_.removeMember("some other id");
+  JSONTEST_ASSERT_EQUAL(Json::Value("foo"), got);
+  got = object1_.removeMember("some other id");
+  JSONTEST_ASSERT_EQUAL(Json::nullValue, got);
 }
 
 JSONTEST_FIXTURE(ValueTest, arrays) {
@@ -240,6 +248,10 @@ JSONTEST_FIXTURE(ValueTest, arrays) {
   array1_[2] = Json::Value(17);
   JSONTEST_ASSERT_EQUAL(Json::Value(), array1_[1]);
   JSONTEST_ASSERT_EQUAL(Json::Value(17), array1_[2]);
+  Json::Value got;
+  JSONTEST_ASSERT_EQUAL(true, array1_.removeIndex(2, &got));
+  JSONTEST_ASSERT_EQUAL(Json::Value(17), got);
+  JSONTEST_ASSERT_EQUAL(false, array1_.removeIndex(2, &got)); // gone now
 }
 
 JSONTEST_FIXTURE(ValueTest, null) {