filter_even.cpp

Get all the even numbers from 0 to 50.

#include <iostream>
 
#include "filter_rdd.h"
#include "generator_rdd.h"
#include "sample_rdd.h"
template <cpark::concepts::Rdd R>
void printRdd(R rdd) {
  for (const cpark::concepts::Split auto& split : rdd) {
    for (const auto& x : split)
      std::cout << x << "\t";
    std::cout << std::endl;
  }
  std::cout << std::endl;
}
 
int main() {
  using namespace cpark;
 
  // Creates execution contexts.
  ExecutionContext default_context{};
 
  // Creates a generator rdd, who holds 50 strings, each containing a number and a "hello".
  std::cout << "Generator rdd : " << std::endl;
  auto generator_rdd = GeneratorRdd(
      0, 50 + 1, [](auto x) { return x; }, &default_context);
  printRdd(generator_rdd);
 
  auto even = [](int i) {
    return 0 == i % 2;
  };
 
  // Test for FilterRdd(const R& prev, Func func) constructor
  std::cout << "Filter rdd (basic): " << std::endl;
  auto filter_rdd_1 = FilterRdd(generator_rdd, even);
  printRdd(filter_rdd_1);
 
  // Test for pipeline and Filter(Func func) operators
  std::cout << "Filter rdd (operators): " << std::endl;
  auto filter_rdd_2 = generator_rdd | Filter(even);
  printRdd(filter_rdd_2);
 
  // Creates a sample rdd with sample ratio of 0.5 using class constructor style
  std::cout << "Sample rdd: " << std::endl;
  auto sample_rdd = SampleRdd(generator_rdd, 0.5);
  printRdd(sample_rdd);
 
  // Creates a sample rdd with sample ratio of 0.5 using pipeline style
  std::cout << "Sample rdd (operators): " << std::endl;
  auto sample_rdd_2 = generator_rdd | Sample(0.5);
  printRdd(sample_rdd_2);
 
  return 0;
}