Interpreting / Reading text files written for Assembly application - c++

Question

I am just starting out in C++.
I am writing a console application, to "read in" an .evt file (custom, not to be confused with Event viewer files in Windows) and its contents but now I need to write a method to.
a) Store each block of 'EVENT X' including but also ending at 'END'.
b) Make the contents of each block searchable/selectable.
If the content wasn't so 'wildly' varied, I would be happy to put this into some SQL table or experiment with an array but I don't know a starting point to do this as the number of 'fields' or parameters varies. The maximum number of lines I have seen in a block is around 20, the maximum number of parameters per line I have seen is around 13.
I'm not asking for an explicit answer or the whole code to do it although it is welcome, just a generic sample of code to get started that might be appropriate.
This my function to just load the data as it is.
void event_data_loader()
{
string evt_data;
string response2;
cout << "You have chosen to Create/Load Soma events\n\n";
ifstream named_EVT("C:/evts/1.evt");
while (getline(named_EVT, evt_data))
{
// Output the text from the file
cout << evt_data << "\n"; // Iterate out each line of the EVT file including spaces
//name_EVT.close();*/
}
cout << "Does the output look ok?(Y/N)";
cin >> response2;
if (response2 == "Y")
{
// Vectors? Dynamic array? to re-arrange the data?
}
}
The files themselves have content like this. I know what most of the functions do, less so all of the parameters. For some reason putting this on the page it puts them into a single line.
EVENT 01
A CHECK_HUMAN
A CHECK_POSITION 1 250 90 350 90
E BBS_OPEN 1 0
END
EVENT 02
E SELECT_MSG 336 363 314 337 03 338 12 -1 -1
END
EVENT 03
E RUN_EVENT 761
E RUN_EVENT 04
E RUN_EVENT 05
END
EVENT 761
A EXIST_ITEM 373 1
E SELECT_MSG 857 315 762 316 763 -1 -1 -1 -1
E RETURN
END
EVENT 762
A EXIST_ITEM 373 1
E ROB_ITEM 373 1
E SHOW_MAGIC 6
E CHANGE_HP 1 10000
E CHANGE_MP 1 10000
E MESSAGE_NONE 858
E RETURN
END
EVENT 1862
A ABSENT_EVENT 1582
A EXIST_ITEM 1800 1
A EXIST_ITEM 1801 1
A EXIST_ITEM 1802 1
A EXIST_ITEM 1803 1
A EXIST_ITEM 1804 1
A EXIST_ITEM 1805 1
A EXIST_ITEM 1806 1
A EXIST_ITEM 1807 1
A WEIGHT 365 1854 1 1832 1 -1 1 -1 -1 -1 -1
A CHECK_ITEMSLOT 393 1854 1 1832 1 -1 1 -1 -1 -1 -1
A GENDER 1
E ADD_EVENT 1582
E MESSAGE_NONE 3237
E ROB_ITEM 1800 1
E ROB_ITEM 1801 1
E ROB_ITEM 1802 1
E ROB_ITEM 1803 1
E ROB_ITEM 1804 1
E ROB_ITEM 1805 1
E ROB_ITEM 1806 1
E ROB_ITEM 1807 1
E GIVE_ITEM 1854 1
E GIVE_ITEM 1832 1
E RETURN
END

Answer 1

I would do something like this:
struct Subevent {
std::string selector;
std::string name;
std::vector<int> params;
};
struct Event {
int id;
std::vector<Subevent> subevents;
};
std::vector<Event> load_events(std::istream& input_stream) {
std::vector<Event> out;
Event current_event {}; // current event being built
std::string line;
bool inside_event = false; // are we inside the scope of an event?
while (std::getline(input_stream, line)) {
// strip trailing whitespace
while (isspace(line.back())) {
line.pop_back();
}
// skip empty lines
if (line.size() == 0) {
continue;
}
// read first token (until first space)
std::stringstream ss(line);
std::string first_token;
ss >> first_token;
bool is_new_event_line = first_token == "EVENT";
bool is_end_line = first_token == "END";
if (is_new_event_line) {
// line: EVENT <id>
if (inside_event) {
// error: "not expecting new event"
// choose your own error messaging method
}
int id;
ss >> id; // read <id>
// setup new event
current_event.id = id;
inside_event = true;
}
else if (is_end_line) {
// line: END
if (!inside_event) {
// error: "unexpected END"
}
// record and clear current event
out.push_back(current_event);
inside_event = false;
current_event = Event();
}
else {
// line: <selector> <name> <params...>
// e.g.: A GENDER 1
if (!inside_event) {
// error: "unexpected property entry"
}
// read subevent
Subevent subevent {};
subevent.selector = first_token;
ss >> subevent.name;
// copy over the int params from the line
std::copy(
std::istream_iterator<int>(ss),
std::istream_iterator<int>(),
std::back_inserter(subevent.params)
);
// push back subevent
event.subevents.push_back(subevent);
}
}
return out;
}