poco/Foundation/include/Poco/NumericString.h
2012-09-30 13:10:51 +00:00

378 lines
9.5 KiB
C++

//
// NumericString.h
//
// $Id: //poco/1.4/Foundation/include/Poco/NumericString.h#1 $
//
// Library: Foundation
// Package: Core
// Module: NumericString
//
// Numeric string utility functions.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
//
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//
#ifndef Foundation_NumericString_INCLUDED
#define Foundation_NumericString_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/FPEnvironment.h"
#ifdef min
#undef min
#endif
#ifdef max
#undef max
#endif
#include <limits>
#include <cmath>
#include <locale>
namespace Poco {
inline char decimalSeparator()
/// Returns decimal separator from global locale or
/// default '.' for platforms where locale is unavailable.
{
#if !defined(POCO_NO_LOCALE)
return std::use_facet<std::numpunct<char> >(std::locale()).decimal_point();
#else
return '.';
#endif
}
inline char thousandSeparator()
/// Returns thousand separator from global locale or
/// default ',' for platforms where locale is unavailable.
{
#if !defined(POCO_NO_LOCALE)
return std::use_facet<std::numpunct<char> >(std::locale()).thousands_sep();
#else
return ',';
#endif
}
template <typename I>
bool strToInt(const char* pStr, I& result, short base = -1)
/// Converts zero-terminated array to integer number;
/// If base is equal to -1, this functin will try to determine
/// the numeric base (using '0' prefix for octal, '0x' for
/// hexadecimal and no prefix for decimal).
/// Thousand separators are recognized for base10 and the locale
/// and silently skipped but not verified for correct positioning.
/// Returns true if succesful. If parsing was unsuccesful,
/// the return value is false with result value undetermined.
{
if (!std::numeric_limits<I>::is_integer) return false;
if (!pStr || (pStr && *pStr == '\0')) return false;
while ((*pStr != '\0') && (*pStr == ' ')) ++pStr;
if (*pStr == '\0') return false;
char sign = 1;
if (*pStr == '-')
{
++pStr;
sign = -1;
}
else if (*pStr == '+') ++pStr;
if (*pStr == '\0') return false;
result = 0;
if (*pStr == '0')
{
while ((*pStr != '\0') && (*pStr == '0')) ++pStr;
if (*pStr == '\0')
{
result = 0;
return true;
}
if ((*pStr == 'x') || (*pStr == 'X'))
{
base = 0x10;
++pStr;
if (*pStr == '\0') return false;
}
else if (base == -1) base = 010;
}
else if (base == -1) base = 10;
while ((*pStr == '0'))
{
if (*pStr != '\0')
{
result = 0;
return true;
}
++pStr;
}
if (*pStr == '\0') return false;
const char thSep = thousandSeparator();
bool allowDigits = true;
for (; *pStr != '\0'; ++pStr)
{
switch (*pStr)
{
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7':
if (allowDigits)
{
if (result > (std::numeric_limits<I>::max() / base)) return false;
result = result * base + (*pStr - '0');
}
else return false;
break;
case '8': case '9':
if (allowDigits && (base == 10 || base == 16))
{
if (result > (std::numeric_limits<I>::max() / base)) return false;
result = result * base + (*pStr - '0');
}
else return false;
break;
case 'a': case 'b': case 'c': case 'd': case 'e': case 'f':
if (allowDigits && base == 16)
{
if (result > (std::numeric_limits<I>::max() / base)) return false;
result = result * base + (10 + *pStr - 'a');
}
else return false;
break;
case 'A': case 'B': case 'C': case 'D': case 'E': case 'F':
if (allowDigits && base == 16)
{
if (result > (std::numeric_limits<I>::max() / base)) return false;
result = result * base + (10 + *pStr - 'A');
}
else
return false;
break;
case 'U':
case 'u':
case 'L':
case 'l':
allowDigits = false;
break;
case '.':
if ((base == 10) && (thSep == '.')) break;
else return false;
case ',':
if ((base == 10) && (thSep == ',')) break;
else return false;
case ' ':
if (base == 10) break;
else return false;
default:
return false;
}
}
if ((base == 10) && (std::numeric_limits<I>::is_signed))
result *= sign;
return true;
}
template <typename I>
bool strToInt(const std::string& str, I& result, short base = -1)
/// Converts string to integer number;
/// This is a wrapper function, for details see see the
/// bool strToInt(const char*, I&, short&) implementation.
{
return strToInt(str.c_str(), result, base);
}
#ifndef POCO_NO_FPENVIRONMENT
namespace {
static char DUMMY_EXP_UNDERFLOW = 0; // dummy default val
}
template <typename F>
bool strToFloat (const char* pStr, F& result, char& eu = DUMMY_EXP_UNDERFLOW)
/// Converts zero-terminated array to floating-point number;
/// Returns true if succesful. Exponent underflow (i.e. loss of precision)
/// is signalled in eu. Thousand separators are recognized for the locale
/// and silently skipped but not verified for correct positioning.
///
/// If parsing was unsuccesful, the return value is false with
/// result and eu values undetermined.
{
if (!pStr || (pStr && *pStr == '\0')) return false;
// parser states:
const char STATE_LEADING_SPACES = 0;
const char STATE_DIGITS_BEFORE_DEC_POINT = 1;
const char STATE_DIGITS_AFTER_DEC_POINT = 2;
const char STATE_EXP_CHAR = 3;
const char STATE_EXP_DIGITS = 4;
const char STATE_SUFFIX = 5; // 'f' suffix
const char decSep = decimalSeparator();
char numSign = 1, expSign = 1;
char state = STATE_LEADING_SPACES;
F mantissa = 0.0, exponent = 0.0;
F pow10 = 1.;
result = 0.0;
eu = 0;
for (; *pStr != '\0'; ++pStr)
{
switch (*pStr)
{
case '.':
if (decSep == '.')
{
if (state > STATE_DIGITS_BEFORE_DEC_POINT) return false;
state = STATE_DIGITS_AFTER_DEC_POINT;
}
break;
case ',':
if (decSep == ',')
{
if (state > STATE_DIGITS_BEFORE_DEC_POINT) return false;
state = STATE_DIGITS_AFTER_DEC_POINT;
}
break;
case ' ':
if ((state > STATE_LEADING_SPACES) && (state < STATE_DIGITS_AFTER_DEC_POINT))
return false;
break;
case '-':
if (state == STATE_LEADING_SPACES)
numSign = -1;
else if (state == STATE_EXP_CHAR) // exponential char
expSign = -1;
else return false;
case '+':
break;
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
if (state >= STATE_SUFFIX) return false; // constant suffix
if (state <= STATE_DIGITS_BEFORE_DEC_POINT) // integral part digits
{
result = result * 10 + (*pStr - '0');
state = STATE_DIGITS_BEFORE_DEC_POINT;
}
else if (state <= STATE_DIGITS_AFTER_DEC_POINT) // fractional part digits
{
mantissa += (*pStr - '0') / (pow10 *= 10.);
state = STATE_DIGITS_AFTER_DEC_POINT;
}
else if (state <= STATE_EXP_DIGITS) // exponent digits
{
exponent = exponent * 10 + (*pStr - '0');
state = STATE_EXP_DIGITS;
}
else return false;
break;
case 'E':
case 'e':
if (state > STATE_DIGITS_AFTER_DEC_POINT) return false;
state = STATE_EXP_CHAR;
break;
case 'F':
case 'f':
state = STATE_SUFFIX;
break;
default:
return false;
}
}
if (exponent > std::numeric_limits<F>::max_exponent10)
{
eu = expSign;
exponent = std::numeric_limits<F>::max_exponent10;
}
result += mantissa;
if (numSign != 1) result *= numSign;
if (exponent > 1.0)
{
F scale = std::pow(10., exponent);
result = (expSign < 0) ? (result / scale) : (result * scale);
}
return (state != STATE_LEADING_SPACES) && // empty/zero-length string
!FPEnvironment::isInfinite(result) &&
!FPEnvironment::isNaN(result);
}
template <typename F>
bool strToFloat (const std::string& s, F& result, char& eu = DUMMY_EXP_UNDERFLOW)
/// Converts string to floating-point number;
/// This is a wrapper function, for details see see the
/// bool strToFloat(const char*, F&, char&) implementation.
{
return strToFloat(s.c_str(), result, eu);
}
#endif // POCO_NO_FPENVIRONMENT
} // namespace Poco
#endif // Foundation_NumericString_INCLUDED