libcruft-util/parse.cpp

102 lines
3.3 KiB
C++

/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*
* Copyright 2017-2018 Danny Robson <danny@nerdcruft.net>
*/
#include "parse.hpp"
#include "cast.hpp"
#include <cstdlib>
#include <stdexcept>
using cruft::parse;
///////////////////////////////////////////////////////////////////////////////
template <typename T> struct c_traits;
template <> struct c_traits<long> { static constexpr auto func = strtol; };
template <> struct c_traits<long long> { static constexpr auto func = strtoll; };
template <> struct c_traits<unsigned long> { static constexpr auto func = strtoul; };
template <> struct c_traits<unsigned long long> { static constexpr auto func = strtoull; };
template <> struct c_traits<float> { static constexpr auto func = strtof; };
template <> struct c_traits<double> { static constexpr auto func = strtod; };
template <> struct c_traits<long double> { static constexpr auto func = strtold; };
//-----------------------------------------------------------------------------
template <typename T>
T
c_iparse (cruft::view<char const*> &data)
{
auto head = const_cast<char *> (data.begin ());
auto tail = head;
auto val = c_traits<T>::func (head, &tail, 0);
if (tail == head)
throw std::invalid_argument ("unable to parse integer");
data = data.consume (tail);
return val;
}
//-----------------------------------------------------------------------------
template <typename T>
T
c_fparse (cruft::view<char const*> &data)
{
auto head = const_cast<char *> (data.begin ());
auto tail = head;
auto val = c_traits<T>::func (head, &tail);
if (tail == head)
throw std::invalid_argument ("unable to parse float");
data = data.consume (tail);
return val;
}
///////////////////////////////////////////////////////////////////////////////
#define C_PARSE(T, KLASS) \
template <> \
T \
cruft::parse<T> ( \
cruft::view<const char *> &str \
) { \
return c_ ## KLASS ## parse<T> (str); \
}
//-----------------------------------------------------------------------------
C_PARSE(long, i)
C_PARSE(long long, i)
C_PARSE(unsigned long, i)
C_PARSE(unsigned long long, i)
C_PARSE(float, f)
C_PARSE(double, f)
C_PARSE(long double, f)
#define C_PARSE_WITH_CAST(FINAL, USED) \
template<> \
FINAL \
cruft::parse<FINAL> (cruft::view<char const*> &str) { \
auto remain = str; \
auto res = parse<USED> (remain); \
if (res > std::numeric_limits<FINAL>::max ()) \
throw std::invalid_argument ("overflow during parse"); \
\
str = remain; \
return cruft::cast::narrow<FINAL> (res); \
}
C_PARSE_WITH_CAST(unsigned int, unsigned long)