// Phil Ottewell's STL Course - http://www.pottsoft.com/home/stl/stl.htmlx
//
// Example 7.1                  © Phil Ottewell 1997 <philXZY@pottsoftXZY_REMOVEXYZ.com>
//
// Purpose:
//          Use map to implement a simple token database

// ANSI C Headers
#include <stdlib.h>

// C++ and STL Headers
#include <fstream>
#include <iostream>
#include <map>
#include <string>

#ifdef _WIN32
using namespace std;
#endif

#ifdef _WIN32
// We know basic_string generates long names
# pragma warning(disable:4786)
#endif

int main( int argc, char *argv[] )
{
    size_t ip, lnum;
    fstream fs;
    string filename, line, token, value;
    map< string, double > token_data;
//  End of declarations ...

    if ( argc > 1) {
      filename = *argv[0];
    } else {
      filename = "tokens.dat";
    }

//  Open the file for reading
    fs.open( filename.c_str(), ios::in );

//  Read each line and parse it
    lnum = 0;
    while ( fs.good() ) {
      getline( fs, line );
      if ( fs.good() ) {
//      Parse out the tokens and values
        ++lnum;
        ip = line.find_first_of("=");
        if ( ip == line.npos ) {
          cerr << "Invalid Line " << lnum << ": " << line << endl;
          continue;
        }
        token = line.substr(0,ip);
        ip = token.find(" ");
        if ( ip != token.npos ) token = token.substr(0,ip);
        value = line.substr(ip+1);
        ip = value.find_first_of("0123456789.+-");
        if ( ip != value.npos ) {
//        Store token and value
          value = value.substr(ip);
          token_data[token] = atof( value.c_str() );
        } else {
          cerr << "Bad value at line " << lnum << ": " << value << endl;
        }
      }

//    Junk everything except alphanumerics, brackets and operators
/*
      ip = 0;
      while ( ip < line.length() ) {
        nxc = line.at(ip);
        if ( isspace(nxc) ||
             (!isalnum(nxc) && !precedence(nxc) &&
              nxc != '(' && nxc != ')') ) {
          line.erase(ip,1);
        } else {
          ++ip;
        }
      }
*/

    }

    if ( !lnum ) {
      cerr << "Invalid or empty file: " << filename << endl;
    } else {
      for ( map< string, double >::iterator im = token_data.begin();
            im != token_data.end(); ++im )
        cout << "\"" << im->first << "\"  = " << im->second << endl;

      cout << "Enter token name: ";
      getline( cin, token );

//    Use the find function so we can spot a "miss"
      im = token_data.find( token );
      if ( im != token_data.end() ) {
        cout << " Found \"" << im->first << "\"  = "
             << im->second << endl;
      } else {
        cout << "token_data.find(...) shows no token matches \"" 
             << token << "\"" << endl;
        cout << "Lookup using token_data[\""
             << token << "\"] would have given "
             << token_data[token] << endl;
      }
    }

    return( EXIT_SUCCESS );
}