//
// This is example code from Chapter 11.7 "Using non-standard separators" of
// "Programming -- Principles and Practice Using C++" by Bjarne Stroustrup
//

#include <algorithm>
#include <iostream>
#include <string>
#include <sstream>
#include <vector>

using namespace std;

//------------------------------------------------------------------------------

class Punct_stream { // like an istream, but the user can add to
                     // the set of whitespace characters
public:
   Punct_stream(istream& is)
      : source{is}, sensitive{true} { }

   void whitespace(const string& s)       // make s the whitespace set
      { white = s; }    
   void add_white(char c) { white += c; } // add to the whitespace set
   bool is_whitespace(char c);            // is c in the whitespace set?

   void case_sensitive(bool b) { sensitive = b; }
   bool is_case_sensitive() { return sensitive; }

   Punct_stream& operator>>(string& s);
   operator bool();
private:
   istream& source;       // character source
   istringstream buffer;  // we let buffer do our formatting
   string white;          // characters considered "whitespace"
   bool sensitive;        // is the stream case sensitive?
};

//------------------------------------------------------------------------------

Punct_stream& Punct_stream::operator>>(string& s)
{
   while (!(buffer>>s)) {    // try to read from buffer
      if (buffer.bad() || !source.good()) return *this;
      buffer.clear();

      string line;
      getline(source,line); // get a line from source

      // do character replacement as needed:
      for (char& ch: line) 
         if (is_whitespace(ch))
            ch = ' ';
         else if (!sensitive)
            ch = tolower(ch);

      buffer.str(line);     // put string into stream
   }
   return *this;
}

//------------------------------------------------------------------------------

bool Punct_stream::is_whitespace(char c)
{
   for (char w: white)
      if (c == w) return true;
   return false;
}

//------------------------------------------------------------------------------

Punct_stream::operator bool()
{
   return !(source.fail() || source.bad()) && source.good();
}

//------------------------------------------------------------------------------

int main()
// given text input, produce a sorted list of all words in that text
// ignore punctuation and case differences
// eliminate duplicates from the output
{
   Punct_stream ps(cin);
   ps.whitespace(";:,.?!()\"{}<>/&$@#%^*|~"); // note \" means " in string
   ps.case_sensitive(false);

   cout << "please enter words\n";
   vector<string> vs;
   for (string word; ps>>word; )
      vs.push_back(word);    // read words

   sort(vs.begin(),vs.end());              // sort in lexicographical order
   for (int i=0; i<vs.size(); ++i)         // write dictionary
      if (i==0 || vs[i]!=vs[i-1]) cout << vs[i] << endl;
}

//------------------------------------------------------------------------------