137 lines
3.4 KiB
C++
137 lines
3.4 KiB
C++
/* operator>> -- C++-style input of mpf_t.
|
|
|
|
Copyright 2001, 2003 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 2.1 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; see the file COPYING.LIB. If not, write to
|
|
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
|
MA 02110-1301, USA. */
|
|
|
|
#include <cctype>
|
|
#include <iostream>
|
|
#include <string>
|
|
#include <clocale> // for localeconv
|
|
|
|
#include "gmp.h"
|
|
#include "gmp-impl.h"
|
|
|
|
using namespace std;
|
|
|
|
|
|
// For g++ libstdc++ parsing see num_get<chartype,initer>::_M_extract_float
|
|
// in include/bits/locale_facets.tcc.
|
|
//
|
|
// There are no plans to accept hex or octal floats, not unless the standard
|
|
// C++ library does so. Although such formats might be of use, it's
|
|
// considered more important to be compatible with what the normal
|
|
// operator>> does on "double"s etc.
|
|
|
|
istream &
|
|
operator>> (istream &i, mpf_ptr f)
|
|
{
|
|
int base;
|
|
char c = 0;
|
|
string s;
|
|
bool ok = false;
|
|
|
|
// C decimal point, as expected by mpf_set_str
|
|
const char *lconv_point = localeconv()->decimal_point;
|
|
|
|
// C++ decimal point
|
|
#if HAVE_STD__LOCALE
|
|
const locale& loc = i.getloc();
|
|
char point_char = use_facet< numpunct<char> >(loc).decimal_point();
|
|
#else
|
|
const char *point = lconv_point;
|
|
char point_char = *point;
|
|
#endif
|
|
|
|
i.get(c); // start reading
|
|
|
|
if (i.flags() & ios::skipws) // skip initial whitespace
|
|
{
|
|
// C++ isspace
|
|
#if HAVE_STD__LOCALE
|
|
const ctype<char>& ct = use_facet< ctype<char> >(loc);
|
|
#define cxx_isspace(c) (ct.is(ctype_base::space,(c)))
|
|
#else
|
|
#define cxx_isspace(c) isspace(c)
|
|
#endif
|
|
|
|
while (cxx_isspace(c) && i.get(c))
|
|
;
|
|
}
|
|
|
|
if (c == '-' || c == '+') // sign
|
|
{
|
|
if (c == '-')
|
|
s = "-";
|
|
i.get(c);
|
|
}
|
|
|
|
base = 10;
|
|
__gmp_istream_set_digits(s, i, c, ok, base); // read the number
|
|
|
|
// look for the C++ radix point, but put the C one in for mpf_set_str
|
|
if (c == point_char)
|
|
{
|
|
#if HAVE_STD__LOCALE
|
|
i.get(c);
|
|
#else // lconv point can be multi-char
|
|
for (;;)
|
|
{
|
|
i.get(c);
|
|
point++;
|
|
if (*point == '\0')
|
|
break;
|
|
if (c != *point)
|
|
goto fail;
|
|
}
|
|
#endif
|
|
s += lconv_point;
|
|
__gmp_istream_set_digits(s, i, c, ok, base); // read the mantissa
|
|
}
|
|
|
|
if (ok && (c == 'e' || c == 'E')) // exponent
|
|
{
|
|
s += c;
|
|
i.get(c);
|
|
ok = false; // exponent is mandatory
|
|
|
|
if (c == '-' || c == '+') // sign
|
|
{
|
|
s += c;
|
|
i.get(c);
|
|
}
|
|
|
|
__gmp_istream_set_digits(s, i, c, ok, base); // read the exponent
|
|
}
|
|
|
|
if (i.good()) // last character read was non-numeric
|
|
i.putback(c);
|
|
else if (i.eof() && ok) // stopped just before eof
|
|
i.clear();
|
|
|
|
if (ok)
|
|
ASSERT_NOCARRY (mpf_set_str(f, s.c_str(), base)); // extract the number
|
|
else
|
|
{
|
|
fail:
|
|
i.setstate(ios::failbit); // read failed
|
|
}
|
|
|
|
return i;
|
|
}
|