Dogcows Code - chaz/yoink/blob - src/stlplus/strings/string_float.cpp

   1 ////////////////////////////////////////////////////////////////////////////////
   2
   3 //   Author:    Andy Rushton
   4 //   Copyright: (c) Southampton University 1999-2004
   5 //              (c) Andy Rushton           2004-2009
   6 //   License:   BSD License, see ../docs/license.html
   7
   8 ////////////////////////////////////////////////////////////////////////////////
   9 #include "string_float.hpp"
  10 #include <stdlib.h>
  11 #include <ctype.h>
  12 #include <stdarg.h>
  13 #include <stdio.h>
  14
  15 namespace stlplus
  16 {
  17
  18   // added as a local copy to break the dependency on the portability library
  19   static std::string local_dformat(const char* format, ...) throw(std::invalid_argument)
  20   {
  21     std::string formatted;
  22     va_list args;
  23     va_start(args, format);
  24 #ifdef MSWINDOWS
  25     int length = 0;
  26     char* buffer = 0;
  27     for(int buffer_length = 256; ; buffer_length*=2)
  28     {
  29       buffer = (char*)malloc(buffer_length);
  30       if (!buffer) throw std::invalid_argument("string_float");
  31       length = _vsnprintf(buffer, buffer_length-1, format, args);
  32       if (length >= 0)
  33       {
  34         buffer[length] = 0;
  35         formatted += std::string(buffer);
  36         free(buffer);
  37         break;
  38       }
  39       free(buffer);
  40     }
  41 #else
  42     char* buffer = 0;
  43     int length = vasprintf(&buffer, format, args);
  44     if (!buffer) throw std::invalid_argument("string_float");
  45     if (length >= 0)
  46       formatted += std::string(buffer);
  47     free(buffer);
  48 #endif
  49     va_end(args);
  50     if (length < 0) throw std::invalid_argument("string_float");
  51     return formatted;
  52   }
  53
  54   ////////////////////////////////////////////////////////////////////////////////
  55   // floating-point types
  56
  57   std::string float_to_string(float f, real_display_t display, unsigned width, unsigned precision)
  58     throw(std::invalid_argument)
  59   {
  60     return double_to_string((double)f, display, width, precision);
  61   }
  62
  63   std::string double_to_string(double f, real_display_t display, unsigned width, unsigned precision)
  64     throw(std::invalid_argument)
  65   {
  66     switch(display)
  67     {
  68     case display_fixed:
  69       return local_dformat("%*.*f", width, precision, f);
  70     case display_floating:
  71       return local_dformat("%*.*e", width, precision, f);
  72     case display_mixed:
  73       return local_dformat("%*.*g", width, precision, f);
  74     default:
  75       throw std::invalid_argument("invalid radix display value");
  76     }
  77   }
  78
  79   ////////////////////////////////////////////////////////////////////////////////
  80
  81   float string_to_float(const std::string& value)
  82     throw(std::invalid_argument)
  83   {
  84     return (float)string_to_double(value);
  85   }
  86
  87   double string_to_double(const std::string& value)
  88     throw(std::invalid_argument)
  89   {
  90     // TODO - error checking
  91     return strtod(value.c_str(), 0);
  92   }
  93
  94   ////////////////////////////////////////////////////////////////////////////////
  95
  96 } // end namespace stlplus