#include <iostream>
#include <iomanip>
#include <string>

using namespace std;

void ClassifyLetter(char letter);
void IsInString(string word, string pattern);

int main() {
    string word = "Hello, World 123!";
    size_t i;

    cout << "The string \"" << word << "\" is "
         << word.size() <<  " characters long." << endl;
    cout << "The string '" << word << "' is "
         << word.size() <<  " characters long." << endl;

    cout << endl << endl;
    cout << "The leters Gare:" << endl;
    for(i=0; i < word.size(); i++) {
       cout << setw(4) << i << "    '" << word[i] << "'     ";
       ClassifyLetter(word[i]);
       cout << endl;
    }

    //  lhs = rhs
    //  the thing on the left hand side gets a copy of the thing on the rhs
    //
    //  x = 3 + 2
    //
    //  cout << word[i] 

    cout << endl << endl;
    IsInString(word, "World");
    IsInString(word, ", W");
    IsInString(word, "l");
    IsInString(word, "nope");

    cout << endl << endl;
    for(i = 0; i < word.size(); i++) {
       cout << "The substring starting at " << i << " is \""
            << word.substr(i) << "\"." << endl;
    }

    cout << endl << endl;
    for(i = 0; i < word.size(); i++) {
       cout << "The substring starting at 2 for " << i << " letters is \""
            << word.substr(2,i) << "\"." << endl;
    }

    cout << endl << endl;
    for(i = 0; i < word.size(); i++) {
        //word[i] = char(toupper(word[i]));
        word[i] = static_cast<char> (toupper(word[i]));
    }

    cout << "After changing to uppercase the word is \""
         << word << "\"." << endl;

   string  phrase = "danger danger danger";
   size_t pos;

   pos = phrase.find("dan");
   while (pos != string::npos) {
      cout << "dan is at position " << pos << endl;
      pos = phrase.find("dan", pos+1);
      //pos = phrase.find("dan", ++pos);
   }

   /*
   
   i++
    ( rv = i;
      i = i + 1
      return rv
    )

    ++i 
    (  i = i + 1
       return i)

   
    */



    return 0;
}

void ClassifyLetter(char letter) {

   if (isalpha(letter)) {
      cout << "a letter";
      if (isupper(letter)) {
         cout <<" (upper case)";
      } else {
         cout <<" (lower case)";
      }
   } else if (isdigit(letter)) {
      cout << "a digit";
   } else if (isspace (letter)) {
      cout << "a whitespace character";
   } else if (ispunct(letter)) {
      cout << "punctuation";
   } else {
      cout << "unknown";
   }
     
   return;
}

void IsInString(string word, string pattern){
   size_t pos;
 
   cout << "Searching for \"" << pattern << "\" in \"" << word << '"' << endl;

   pos = word.find(pattern);
   if (pos == string::npos) {
      cout  << "\t\"" << pattern << "\" is not in the string." << endl;
   } else {
      cout  << "\t\"" << pattern << "\" is in the string at position " 
            << pos << "." << endl;
   }

   return;
}