source/libs/mpfr/mpfr-3.1.3/src/out_str.c

   1 /* mpfr_out_str -- output a floating-point number to a stream
   2
   3 Copyright 1999, 2001-2002, 2004, 2006-2015 Free Software Foundation, Inc.
   4 Contributed by the AriC and Caramel projects, INRIA.
   5
   6 This file is part of the GNU MPFR Library.
   7
   8 The GNU MPFR Library is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU Lesser General Public License as published by
  10 the Free Software Foundation; either version 3 of the License, or (at your
  11 option) any later version.
  12
  13 The GNU MPFR Library is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
  15 or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  16 License for more details.
  17
  18 You should have received a copy of the GNU Lesser General Public License
  19 along with the GNU MPFR Library; see the file COPYING.LESSER.  If not, see
  20 http://www.gnu.org/licenses/ or write to the Free Software Foundation, Inc.,
  21 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA. */
  22
  23 #include "mpfr-impl.h"
  24
  25 /* Warning! S should not contain "%". */
  26 #define OUT_STR_RET(S)                          \
  27   do                                            \
  28     {                                           \
  29       int r;                                    \
  30       r = fprintf (stream, (S));                \
  31       return r < 0 ? 0 : r;                     \
  32     }                                           \
  33   while (0)
  34
  35 size_t
  36 mpfr_out_str (FILE *stream, int base, size_t n_digits, mpfr_srcptr op,
  37               mpfr_rnd_t rnd_mode)
  38 {
  39   char *s, *s0;
  40   size_t l;
  41   mpfr_exp_t e;
  42   int err;
  43
  44   MPFR_ASSERTN (base >= 2 && base <= 62);
  45
  46   /* when stream=NULL, output to stdout */
  47   if (stream == NULL)
  48     stream = stdout;
  49
  50   if (MPFR_UNLIKELY (MPFR_IS_SINGULAR (op)))
  51     {
  52       if (MPFR_IS_NAN (op))
  53         OUT_STR_RET ("@NaN@");
  54       else if (MPFR_IS_INF (op))
  55         OUT_STR_RET (MPFR_IS_POS (op) ? "@Inf@" : "-@Inf@");
  56       else
  57         {
  58           MPFR_ASSERTD (MPFR_IS_ZERO (op));
  59           OUT_STR_RET (MPFR_IS_POS (op) ? "0" : "-0");
  60         }
  61     }
  62
  63   s = mpfr_get_str (NULL, &e, base, n_digits, op, rnd_mode);
  64
  65   s0 = s;
  66   /* for op=3.1416 we have s = "31416" and e = 1 */
  67
  68   l = strlen (s) + 1; /* size of allocated block returned by mpfr_get_str
  69                          - may be incorrect, as only an upper bound? */
  70
  71   /* outputs possible sign and significand */
  72   err = (*s == '-' && fputc (*s++, stream) == EOF)
  73     || fputc (*s++, stream) == EOF  /* leading digit */
  74     || fputc ((unsigned char) MPFR_DECIMAL_POINT, stream) == EOF
  75     || fputs (s, stream) == EOF;     /* trailing significand */
  76   (*__gmp_free_func) (s0, l);
  77   if (MPFR_UNLIKELY (err))
  78     return 0;
  79
  80   e--;  /* due to the leading digit */
  81
  82   /* outputs exponent */
  83   if (e)
  84     {
  85       int r;
  86
  87       MPFR_ASSERTN(e >= LONG_MIN);
  88       MPFR_ASSERTN(e <= LONG_MAX);
  89
  90       r = fprintf (stream, (base <= 10 ? "e%ld" : "@%ld"), (long) e);
  91       if (MPFR_UNLIKELY (r < 0))
  92         return 0;
  93
  94       l += r;
  95     }
  96
  97   return l;
  98 }