/* Auxiliary functions for C++-style input of GMP types.

Copyright 2001 Free Software Foundation, Inc.

This file is part of the GNU MP Library.

The GNU MP Library is free software; you can redistribute it and/or modify
it under the terms of the GNU Lesser General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at your
option) any later version.

The GNU MP Library is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public License
along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.  */

#include <cctype>
#include <iostream>
#include <string>
#include "gmp.h"
#include "gmp-impl.h"

using namespace std;


int
__gmp_istream_set_base (istream &i, char &c, bool &zero, bool &showbase)
{
  int base;

  zero = showbase = false;
  switch (i.flags() & ios::basefield)
    {
    case ios::dec:
      base = 10;
      break;
    case ios::hex:
      base = 16;
      break;
    case ios::oct:
      base = 8;
      break;
    default:
      showbase = true; // look for initial "0" or "0x" or "0X"
      if (c == '0')
	{
	  if (! i.get(c))
	    c = 0; // reset or we might loop indefinitely

	  if (c == 'x' || c == 'X')
	    {
	      base = 16;
	      i.get(c);
	    }
	  else
	    {
	      base = 8;
	      zero = true; // if no other digit is read, the "0" counts
	    }
	}
      else
	base = 10;
      break;
    }

  return base;
}

void
__gmp_istream_set_digits (string &s, istream &i, char &c, bool &ok, int base)
{
  switch (base)
    {
    case 10:
      while (isdigit(c))
	{
	  ok = true; // at least a valid digit was read
	  s += c;
	  if (! i.get(c))
	    break;
	}
      break;
    case 8:
      while (isdigit(c) && c != '8' && c != '9')
	{
	  ok = true; // at least a valid digit was read
	  s += c;
	  if (! i.get(c))
	    break;
	}
      break;
    case 16:
      while (isxdigit(c))
	{
	  ok = true; // at least a valid digit was read
	  s += c;
	  if (! i.get(c))
	    break;
	}
      break;
    }
}