tomlplusplus/include/toml++/toml_utf8_streams.hpp
2021-05-06 15:56:36 +03:00

111 lines
2.6 KiB
C++

//# This file is a part of toml++ and is subject to the the terms of the MIT license.
//# Copyright (c) Mark Gillard <mark.gillard@outlook.com.au>
//# See https://github.com/marzer/tomlplusplus/blob/master/LICENSE for the full license text.
// SPDX-License-Identifier: MIT
#pragma once
//# {{
#include "toml_preprocessor.h"
#if !TOML_IMPLEMENTATION
#error This is an implementation-only header.
#endif
#if !TOML_PARSER
#error This header cannot not be included when TOML_PARSER is disabled.
#endif
//# }}
#include "toml_utf8_streams.h"
#if !TOML_EXCEPTIONS
#undef TOML_ERROR_CHECK
#define TOML_ERROR_CHECK if (reader.error()) return nullptr
#endif
TOML_IMPL_NAMESPACE_START
{
TOML_ABI_NAMESPACE_BOOL(TOML_EXCEPTIONS, ex, noex);
TOML_EXTERNAL_LINKAGE
utf8_buffered_reader::utf8_buffered_reader(utf8_reader_interface& reader_) noexcept
: reader{ reader_ }
{}
TOML_EXTERNAL_LINKAGE
const source_path_ptr& utf8_buffered_reader::source_path() const noexcept
{
return reader.source_path();
}
TOML_EXTERNAL_LINKAGE
const utf8_codepoint* utf8_buffered_reader::read_next()
{
TOML_ERROR_CHECK;
if (negative_offset)
{
negative_offset--;
// an entry negative offset of 1 just means "replay the current head"
if (!negative_offset)
return head;
// otherwise step back into the history buffer
else
return history.buffer + ((history.first + history.count - negative_offset) % history_buffer_size);
}
else
{
// first character read from stream
if TOML_UNLIKELY(!history.count && !head)
head = reader.read_next();
// subsequent characters and not eof
else if (head)
{
if TOML_UNLIKELY(history.count < history_buffer_size)
history.buffer[history.count++] = *head;
else
history.buffer[(history.first++ + history_buffer_size) % history_buffer_size] = *head;
head = reader.read_next();
}
return head;
}
}
TOML_EXTERNAL_LINKAGE
const utf8_codepoint* utf8_buffered_reader::step_back(size_t count) noexcept
{
TOML_ERROR_CHECK;
TOML_ASSERT(history.count);
TOML_ASSERT(negative_offset + count <= history.count);
negative_offset += count;
return negative_offset
? history.buffer + ((history.first + history.count - negative_offset) % history_buffer_size)
: head;
}
TOML_EXTERNAL_LINKAGE
bool utf8_buffered_reader::peek_eof() const
{
return reader.peek_eof();
}
#if !TOML_EXCEPTIONS
TOML_EXTERNAL_LINKAGE
optional<parse_error>&& utf8_buffered_reader::error() noexcept
{
return reader.error();
}
#endif
TOML_ABI_NAMESPACE_END; // TOML_EXCEPTIONS
}
TOML_IMPL_NAMESPACE_END;
#undef TOML_ERROR_CHECK
#undef TOML_ERROR