ladybird/AK/UnicodeUtils.h
Daniel Bertalan c8367df746 LibC: Implement wcrtomb
This function converts a single wide character into its multibyte
representation (UTF-8 in our case). It is called from libc++'s
`std::basic_ostream<wchar_t>::flush`, which gets called at program exit
from a global destructor in order to flush `std::wcout`.
2021-10-15 21:50:19 -07:00

45 lines
1.3 KiB
C++

/*
* Copyright (c) 2021, Max Wipfli <mail@maxwipfli.ch>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Forward.h>
namespace AK::UnicodeUtils {
constexpr bool is_unicode_control_code_point(u32 code_point)
{
return code_point < 0x20 || (code_point >= 0x80 && code_point < 0xa0);
}
Optional<StringView> get_unicode_control_code_point_alias(u32);
template<typename Callback>
[[nodiscard]] constexpr int code_point_to_utf8(u32 code_point, Callback callback)
{
if (code_point <= 0x7f) {
callback((char)code_point);
return 1;
} else if (code_point <= 0x07ff) {
callback((char)(((code_point >> 6) & 0x1f) | 0xc0));
callback((char)(((code_point >> 0) & 0x3f) | 0x80));
return 2;
} else if (code_point <= 0xffff) {
callback((char)(((code_point >> 12) & 0x0f) | 0xe0));
callback((char)(((code_point >> 6) & 0x3f) | 0x80));
callback((char)(((code_point >> 0) & 0x3f) | 0x80));
return 3;
} else if (code_point <= 0x10ffff) {
callback((char)(((code_point >> 18) & 0x07) | 0xf0));
callback((char)(((code_point >> 12) & 0x3f) | 0x80));
callback((char)(((code_point >> 6) & 0x3f) | 0x80));
callback((char)(((code_point >> 0) & 0x3f) | 0x80));
return 4;
}
return -1;
}
}