gsc-tool/src/gsc/misc/lookahead.cpp

41 lines
766 B
C++

// Copyright 2023 xensik. All rights reserved.
//
// Use of this source code is governed by a GNU GPLv3 license
// that can be found in the LICENSE file.
#include "stdinc.hpp"
#include "lookahead.hpp"
namespace xsk::gsc
{
lookahead::lookahead(char const* data, usize size) : buffer_pos{ 0 }, available{ 0 }, last_byte{ 0 }, curr_byte{ 0 }
{
if (data && size)
{
buffer_pos = data;
available = size;
last_byte = 0;
curr_byte = *data;
}
}
auto lookahead::advance() -> void
{
++buffer_pos;
if (available-- == 1)
{
available = 0;
last_byte = curr_byte;
curr_byte = 0;
}
else
{
last_byte = curr_byte;
curr_byte = *buffer_pos;
}
}
} // namespace xsk::gsc