Question

Below is the section I am having trouble with

        if(transition == *(vec.end()-1)) { //vec contains the ASCI code
            vec.pop_back();
            --vec_index;
            result.append(vec[vec_index]);
        } else if(colors.find(modified.substr(1)) == colors.end()) {
            cout << result << endl;
            cout << "\033[0;37m";
            cerr << "**ERROR: INVALID CLOSING COLOR TAG ON LINE: "
            //cerr << "**ERROR: OVERLAPPING CLOSING COLOR TAG ON LINE: "
            << nlines << endl;
            exit(0);
        } else {
            cout << result << endl;
            cout << "\033[0;37m";
            cerr << "**ERROR: INVALID CLOSING COLOR TAG ON LINE: "
            //cerr << "**ERROR: OVERLAPPING CLOSING COLOR TAG ON LINE: "
            << nlines << endl;
            exit(0);
        }

In the above code, my else-if statement does not seem to execute at all. What I am trying to do is when modified.substr(1) is not found in the map is print the first error otherwise (the color string is in the map but it’s not the same one as the last one in the vector) print the “else” error. However, my else case is always printing. The reason why it’s modified.substr(1) is because modified (in this case) starts with a /.

Answer 1

transition = colors[modified.substr(1)];

will create an entry in map<> color; if it’s not existing and value initialize it. That’s why your else if condition will never be true. Use map::find instead of operator [] to find the entry. Something like,

map<string,string>::const_iterator it = colors.find(modified.substr(1)];

And use it instead of transition. You can de-reference it (as it->first for key and it->second for string-value) when needed to get the underlying string.