for (size_t i = 0; i != insertion.size(); ++i) {
for (pos_type j = 0; j != insertion[i].size(); ++j) {
if (insertion[i].isNewline(j)) {
// do not track deletion of newline
insertion[i].eraseChar(j, false);
for (size_t i = 0; i != insertion.size(); ++i) {
for (pos_type j = 0; j != insertion[i].size(); ++j) {
if (insertion[i].isNewline(j)) {
// do not track deletion of newline
insertion[i].eraseChar(j, false);