///////    File CalcFace.C    ///////
#include  <iostream.h>
#include  <strstream.h>
#include  <string.h>
#include  <ctype.h>
#include    "CalcFace.h"

int in_string(char c, char *str)         // file scope
{     int i = 0;                       
      while (str[i] != '\0')
      {   if (str[i] == c) return(1);    // return true
          i++;
      }
      return(0);                         // return false
}

inline int CalcFace::nump(char c)
       {  return( c == '.' || isdigit(c) );  }

void CalcFace::extract_number(double& number)
{   if ( nbuf[0] == '\0' )
        number = 0.0;
    else
    {   istrstream tmp(nbuf, PREC + 1);
        tmp >> number;
    }
}

int CalcFace::input(char& op, double& number)
{  int c, current_position = 0, num=0;
       while ( (c = inchar()) != 'q' && c != 'Q' )    // (1)
       {   if ( in_string(c, keys) )                  // if c an operator
           {  op = c; 
              if ( num ) 
              {   nbuf[current_position] = '\0';
                  extract_number(number);
                  return(0);
              }
              else return(OPONLY);
           }
           if ( nump(c) && current_position < PREC )  // (2)
           {  num = 1;
              build_number(c, current_position);
           }
       }  // end of while
       return(OFF);  // end of input
}


void CalcFace::build_number(char c, int& i)
{    static int point_seen = 0;
     if ( i == 0 ) point_seen = 0;        // reset
     if ( i == 0 && c == '0') return;     // ignore leading zeros
     if ( c == '.' )                      // at most one decimal point
     {    if ( point_seen ) return;
          else point_seen = 1;
     }
     nbuf[i++] = c;                       // current_position++
}

void CalcFace::show_number(double number)
{ 
    cout << "Calc:  " << number << "\n";
}