example3.cpp

#include <vector>
#include <iostream>
#include <unordered_map>
#include <string>
#include <ewah.h>
#include <string>
#include <algorithm>
#include <fstream>
#include <sstream>

using namespace std;

/**
* Simple DEMO to test the intersects function
*/

unordered_map<string, EWAHBoolArray<uint32_t>> indexColumn(vector<string> col) {
  unordered_map<string, EWAHBoolArray<uint32_t>> indexes;
  for (size_t i = 0; i < col.size(); i++) {
    indexes[col[i]].set(i);
  }
  return indexes;
}

int main() {

  // read the data from the CSV file
  vector<string> col1, col2;
  ifstream infile("data/data.csv");

  while (infile) {
    string s;
    if (!getline(infile, s))
      break;

    istringstream ss(s);

    int numCommas = 0;
    while (ss) {
      if (!getline(ss, s, ','))
        break;
      if (numCommas == 0) {
        col1.push_back(s);
        numCommas++;
      } else {
        col2.push_back(s);
        numCommas = 0;
      }
    }
  }

  unordered_map<string, EWAHBoolArray<uint32_t>> index1 = indexColumn(col1);
  unordered_map<string, EWAHBoolArray<uint32_t>> index2 = indexColumn(col2);
  size_t testcount = 0;

  for (unordered_map<string, EWAHBoolArray<uint32_t>>::iterator i =
           index1.begin();
       i != index1.end(); ++i) {
    EWAHBoolArray<uint32_t> &bitmap1 = i->second;
    for (unordered_map<string, EWAHBoolArray<uint32_t>>::iterator j =
             index2.begin();
         j != index2.end(); ++j) {
      EWAHBoolArray<uint32_t> &bitmap2 = j->second;
      bool intersect = bitmap1.intersects(bitmap2);
      EWAHBoolArray<uint32_t> result;
      testcount++;
      bitmap1.logicaland(bitmap2, result);
      if (intersect) {
        assert(result.numberOfOnes() > 0);
      } else {
        assert(result.numberOfOnes() == 0);
      }
    }
  }
  cout << "Ran " << testcount << " tests. Your code is probably ok. " << endl;

  return 0;
}