libcruft-util/ascii.hpp

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/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Copyright 2016-2018 Danny Robson <danny@nerdcruft.net>
*/
#ifndef CRUFT_UTIL_ASCII_HPP
#define CRUFT_UTIL_ASCII_HPP
#include "annotation.hpp"
#include <cstdint>
#include <stdexcept>
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namespace util::ascii {
///////////////////////////////////////////////////////////////////////////
constexpr inline
bool
is_digit (char c) noexcept
{
return c >= '0' && c <= '9';
}
//-------------------------------------------------------------------------
constexpr inline
uint8_t
to_integer (char c)
{
return likely (is_digit (c)) ?
c - '0'
: throw std::invalid_argument ("character is not a digit");
}
//-------------------------------------------------------------------------
constexpr inline
bool
is_upper (char c) noexcept
{
return c >= 'A' && c <= 'Z';
}
//-------------------------------------------------------------------------
constexpr inline
bool
is_lower (char c) noexcept
{
return c >= 'a' && c <= 'z';
}
//-------------------------------------------------------------------------
constexpr inline
bool
is_hex (const char c) noexcept
{
switch (c) {
case '0'...'9': return true;
case 'a'...'f': return true;
case 'A'...'F': return true;
}
return false;
}
//-------------------------------------------------------------------------
constexpr inline
uint8_t
from_hex (char c)
{
return c >= '0' && c <= '9' ? (c - '0' ) :
c >= 'a' && c <= 'f' ? (c - 'a' + 10) :
c >= 'A' && c <= 'F' ? (c - 'A' + 10) :
throw std::invalid_argument ("character is not hexademical");
}
///////////////////////////////////////////////////////////////////////////
constexpr inline
char
to_upper (char c) noexcept
{
return c - 'a' + 'A';
}
//-------------------------------------------------------------------------
constexpr inline
char
to_lower (char c) noexcept
{
return c - 'A' + 'a';
}
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///////////////////////////////////////////////////////////////////////////
constexpr inline
bool
is_space (char c)
{
switch (c) {
case ' ':
case '\f':
case '\n':
case '\r':
case '\t':
case '\v':
return true;
default:
return false;
}
}
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}
///////////////////////////////////////////////////////////////////////////////
#include "debug.hpp"
#include <vector>
/// convert an ascii string of hex digits into a vector of uint8
std::vector<std::uint8_t>
inline
operator"" _hex2u8 (const char *str, size_t len)
{
CHECK_MOD (len, 2);
std::vector<uint8_t> res (len/2);
for (size_t i = 0; i < len; i += 2)
res[i/2] = util::ascii::from_hex (str[i]) << 4 | util::ascii::from_hex (str[i+1]);
return res;
};
///////////////////////////////////////////////////////////////////////////////
template <typename CharT, CharT ...StrV>
constexpr auto
operator"" _hex2array (void)
{
static_assert (sizeof ...(StrV) % 2 == 0);
std::array<std::uint8_t,sizeof...(StrV)/2> res {};
constexpr CharT literal[] = { StrV... };
for (size_t i = 0; i < res.size (); ++i)
res[i] = util::ascii::from_hex (literal[i*2+0]) << 4 |
util::ascii::from_hex (literal[i*2+1]);
return res;
}
#endif