TextQuery.cpp

#include "TextQuery.h"
#include <sstream>
#include <string>
#include <vector>
#include <map>
#include <set>
#include <iostream>
#include <regex>
using namespace std;
TextQuery::TextQuery(ifstream &is):file(new vector<string>)
{
    string text;
    while (getline(is, text)) {
        file->push_back(text);     // remember this line of text
        int n = file->size() - 1;  // the current line number
        istringstream line(text);  // separate the line into words
        string word;  
      //  cout << word<<endl;             
        while (line >> word) {     // for each word in that line
        auto &lines = wm[word];    // lines is a shared_ptr 
        if (!lines)                // that pointer is null the first time we see word
            lines.reset(new set<line_no>); // allocate a new set
          
            lines->insert(n);      // insert this line number
        }
    }
}


QueryResult TextQuery::query(const string &sought) const
{
    // we'll return a pointer to this empty set if we don't find sought
    static shared_ptr<set<line_no>> nodata(new set<line_no>); 
    // use find and not a subscript to avoid adding words to wm!
    auto loc = wm.find(sought);
    if (loc == wm.end()) 
        return QueryResult(sought, nodata, file);  // not found
    else 
        return QueryResult(sought, loc->second, file);
}

// debugging routine
void TextQuery::display_map()
{
    for (auto iter_wm = wm.cbegin() ; iter_wm != wm.cend(); ++iter_wm) {
        cout << iter_wm->first << ": ";
        for(auto iter_num = iter_wm->second->cbegin() ; iter_num != iter_wm->second->cend() ; ++iter_num)
            cout << *iter_num << " ";
        cout << endl;
    }
    cout << endl;
}

//std::ostream &print(std::ostream &os, const QueryResult &qr)
//{
  //  os << "\"" << qr.sought << "\"" << " occurs " << 
    //        qr.lines->size() << " times:" <<std::endl;
  //for (auto num : *qr.lines)
    //{
      //  os << "\t(line " << num + 1 << ") " 
        //    << *(qr.file->begin() + num) << std::endl;
    //}
    //return os;}