mirror of
https://github.com/geode-sdk/geode.git
synced 2024-12-12 09:01:17 -05:00
89 lines
2.8 KiB
C++
Executable file
89 lines
2.8 KiB
C++
Executable file
// Copyright (c) 2014-2022 Dr. Colin Hirsch and Daniel Frey
|
|
// Please see LICENSE for license or visit https://github.com/taocpp/PEGTL/
|
|
|
|
#ifndef TAO_PEGTL_INTERNAL_PEEK_UTF8_HPP
|
|
#define TAO_PEGTL_INTERNAL_PEEK_UTF8_HPP
|
|
|
|
#include "../config.hpp"
|
|
|
|
#include "input_pair.hpp"
|
|
|
|
namespace TAO_PEGTL_NAMESPACE::internal
|
|
{
|
|
struct peek_utf8
|
|
{
|
|
using data_t = char32_t;
|
|
using pair_t = input_pair< char32_t >;
|
|
|
|
template< typename ParseInput >
|
|
[[nodiscard]] static pair_t peek( ParseInput& in ) noexcept( noexcept( in.empty() ) )
|
|
{
|
|
if( in.empty() ) {
|
|
return { 0, 0 };
|
|
}
|
|
const char32_t c0 = in.peek_uint8();
|
|
if( ( c0 & 0x80 ) == 0 ) {
|
|
return { c0, 1 };
|
|
}
|
|
return peek_impl( in, c0 );
|
|
}
|
|
|
|
private:
|
|
template< typename ParseInput >
|
|
[[nodiscard]] static pair_t peek_impl( ParseInput& in, char32_t c0 ) noexcept( noexcept( in.size( 4 ) ) )
|
|
{
|
|
if( ( c0 & 0xE0 ) == 0xC0 ) {
|
|
if( in.size( 2 ) >= 2 ) {
|
|
const char32_t c1 = in.peek_uint8( 1 );
|
|
if( ( c1 & 0xC0 ) == 0x80 ) {
|
|
c0 &= 0x1F;
|
|
c0 <<= 6;
|
|
c0 |= ( c1 & 0x3F );
|
|
if( c0 >= 0x80 ) {
|
|
return { c0, 2 };
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else if( ( c0 & 0xF0 ) == 0xE0 ) {
|
|
if( in.size( 3 ) >= 3 ) {
|
|
const char32_t c1 = in.peek_uint8( 1 );
|
|
const char32_t c2 = in.peek_uint8( 2 );
|
|
if( ( ( c1 & 0xC0 ) == 0x80 ) && ( ( c2 & 0xC0 ) == 0x80 ) ) {
|
|
c0 &= 0x0F;
|
|
c0 <<= 6;
|
|
c0 |= ( c1 & 0x3F );
|
|
c0 <<= 6;
|
|
c0 |= ( c2 & 0x3F );
|
|
if( c0 >= 0x800 && !( c0 >= 0xD800 && c0 <= 0xDFFF ) ) {
|
|
return { c0, 3 };
|
|
}
|
|
}
|
|
}
|
|
}
|
|
else if( ( c0 & 0xF8 ) == 0xF0 ) {
|
|
if( in.size( 4 ) >= 4 ) {
|
|
const char32_t c1 = in.peek_uint8( 1 );
|
|
const char32_t c2 = in.peek_uint8( 2 );
|
|
const char32_t c3 = in.peek_uint8( 3 );
|
|
if( ( ( c1 & 0xC0 ) == 0x80 ) && ( ( c2 & 0xC0 ) == 0x80 ) && ( ( c3 & 0xC0 ) == 0x80 ) ) {
|
|
c0 &= 0x07;
|
|
c0 <<= 6;
|
|
c0 |= ( c1 & 0x3F );
|
|
c0 <<= 6;
|
|
c0 |= ( c2 & 0x3F );
|
|
c0 <<= 6;
|
|
c0 |= ( c3 & 0x3F );
|
|
if( c0 >= 0x10000 && c0 <= 0x10FFFF ) {
|
|
return { c0, 4 };
|
|
}
|
|
}
|
|
}
|
|
}
|
|
return { 0, 0 };
|
|
}
|
|
};
|
|
|
|
} // namespace TAO_PEGTL_NAMESPACE::internal
|
|
|
|
#endif
|