#include <iostream>
#include <regex>
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  if (std::regex_match ("subject", std::regex("(sub)(.*)") ))
    std::cout << "string literal matched\n";

  const char cstr[] = "subject peppo lello gianni andrea paolo mimmo antonio francesco giovanni giuseppe filippo roberto";
  std::string s ("subject");
  std::regex e ("(sub)(.*)");    

  if (std::regex_match (s,e))
    std::cout << "string object matched\n";

  if ( std::regex_match ( s.begin(), s.end(), e ) )
    std::cout << "range matched\n";  

  std::cmatch cm;    // same as std::match_results<const char*> cm;
  std::regex_match (cstr,cm,e);
  std::cout << "string literal with " << cm.size() << " matches\n";

  std::smatch sm;    // same as std::match_results<string::const_iterator> sm;
  std::regex_match (s,sm,e);
  std::cout << "string object with " << sm.size() << " matches\n";

  std::regex_match ( s.cbegin(), s.cend(), sm, e);
  std::cout << "range with " << sm.size() << " matches\n";

  // using explicit flags:
  std::regex_match ( cstr, cm, e, std::regex_constants::match_default );

  std::cout << "the matches were: ";
  for (unsigned i=0; i<cm.size(); ++i) {
    std::cout << "[" << cm[i] << "] ";
  }

  std::cout << std::endl;    


  s = "this subject has a submarine as a subsequence";
  std::smatch m;
  e = std::regex("\\b(sub)([^ ]*)");   // matches words beginning by "sub"

  std::cout << "Target sequence: " << s << std::endl;
  std::cout << "Regular expression: /\\b(sub)([^ ]*)/" << std::endl;
  std::cout << "The following matches and submatches were found:" << std::endl;

  while (std::regex_search (s,m,e)) {
    for (auto x:m) std::cout << x << " ";
    std::cout << std::endl;
    s = m.suffix().str();
  }

  std::cout << std::endl; 


  s = "there is a subsequence in the string\n";
  e = std::regex("\\b(sub)([^ ]*)");   // matches words beginning by "sub"

  // using string/c-string (3) version:
  std::cout << std::regex_replace (s,e,"sub-$2");

  // using range/c-string (6) version:
  std::string result;
  std::regex_replace (std::back_inserter(result), s.begin(), s.end(), e, "$2");
  std::cout << result;

  // with flags:
  std::cout << std::regex_replace (s,e,"$1 and $2",std::regex_constants::format_no_copy);
  std::cout << std::endl;

}

void loop() {
  return;
  // put your main code here, to run repeatedly:
  delay(1000); // this speeds up the simulation
 

  std::string s ("subject cotto e mangiato");
  std::regex e ("(sub)(.*t) (.*)");    

  //std::smatch sm;    // same as std::match_results<string::const_iterator> sm;
  std::smatch sm; 
  std::regex_match (s,sm,e);
  std::cout << "string object with " << sm.size() << " matches\n";
  std::cout << "the matches were: ";
  for (unsigned i=0; i<sm.size(); ++i) {
    std::cout << "[" << sm[i] << "] ";
  }
  std::cout << std::endl; 
  Serial.printf("ramfree %d\n", ESP.getFreeHeap());
  // Release memory allocated by matches
  sm = std::smatch();
  Serial.printf("ramfree %d\n", ESP.getFreeHeap());



  
}