提升精神 2：在 qi::parser 上跟随进度百分比。我的代码有什么问题？
boost spirit 2 : following progression percentage on qi::parser. What's bad in my code?
使用 Boost Spirit 2 进行开发，我正在努力遵循 example in order to get progression (will add semantic actions later) in my pgn parser (see also ). But I can't manage to avoid compilation errors : cpp
#include "pgn_games_extractor.h"
#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <tuple>
#include <iostream>
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_tag, key, value)
BOOST_FUSION_ADAPT_STRUCT(loloof64::game_move, move_number, white_move, black_move, result)
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_game, header, moves)
namespace loloof64 {
namespace qi = boost::spirit::qi;
typedef std::tuple<std::size_t, game_move> move_t;
typedef std::tuple<std::vector<pgn_tag>, std::vector<move_t>> game_t;
typedef std::tuple<std::size_t, std::vector<game_t>> pgn_t;
template <typename Iterator> struct pgn_parser : qi::grammar<Iterator, std::vector<pgn_game>, qi::space_type> {
pgn_parser() : pgn_parser::base_type(games) {
using namespace qi;
CurrentPos<Iterator> filepos;
const std::string no_move;
result.add
("1-0", result_t::white_won)
("0-1", result_t::black_won)
("1/2-1/2", result_t::draw)
("*", result_t::undecided);
quoted_string = '"' >> *~char_('"') >> '"';
tag = '[' >> +alnum >> quoted_string >> ']';
header = +tag;
regular_move = lit("O-O-O") | "O-O" | (+char_("a-hNBRQK") >> +char_("a-h1-8x=NBRQK") >> -lit("e.p."));
single_move = raw [ regular_move >> -char_("+#") ];
full_move = filepos.current_pos >> uint_
>> (lexeme["..." >> attr(no_move)] | "." >> single_move)
>> (single_move | attr(no_move))
>> -result;
game_description = +full_move;
single_game = -header >> game_description;
games = filepos.save_start_pos >> *single_game;
BOOST_SPIRIT_DEBUG_NODES(
(tag)(header)(quoted_string)(regular_move)(single_move)
(full_move)(game_description)(single_game)(games)
)
}
private:
qi::rule<Iterator, pgn_tag(), qi::space_type> tag;
qi::rule<Iterator, std::vector<pgn_tag>, qi::space_type> header;
qi::rule<Iterator, move_t(), qi::space_type> full_move;
qi::rule<Iterator, std::vector<move_t>, qi::space_type> game_description;
qi::rule<Iterator, game_t(), qi::space_type> single_game;
qi::rule<Iterator, pgn_t(), qi::space_type> games;
// lexemes
qi::symbols<char, result_t> result;
qi::rule<Iterator, std::string()> quoted_string;
qi::rule<Iterator> regular_move;
qi::rule<Iterator, std::string()> single_move;
};
}
loloof64::PgnGamesExtractor::PgnGamesExtractor(std::string inputFilePath) {
std::ifstream inputFile(inputFilePath);
parseInput(inputFile);
}
loloof64::PgnGamesExtractor::PgnGamesExtractor(std::istream &inputFile) { parseInput(inputFile); }
loloof64::PgnGamesExtractor::~PgnGamesExtractor() {
// dtor
}
void loloof64::PgnGamesExtractor::parseInput(std::istream &inputFile) {
if (inputFile.fail() || inputFile.bad())
throw new InputFileException("Could not read the input file !");
typedef boost::spirit::istream_iterator It;
loloof64::pgn_parser<It> parser;
std::vector<loloof64::pgn_game> temp_games;
It iter(inputFile >> std::noskipws), end;
//////////////////////////////////
std::cout << "About to parse the file" << std::endl;
//////////////////////////////////
bool success = boost::spirit::qi::phrase_parse(iter, end, parser, boost::spirit::qi::space, temp_games);
//////////////////////////////////
std::cout << "Finished to parse the file" << std::endl;
//////////////////////////////////
if (success && iter == end) {
games.swap(temp_games);
} else {
std::string error_fragment(iter, end);
throw PgnParsingException("Failed to parse the input at :'" + error_fragment + "' !");
}
}
和头文件：header.
#ifndef PGNGAMESEXTRACTOR_HPP
#define PGNGAMESEXTRACTOR_HPP
#include <string>
#include <vector>
#include <fstream>
#include <stdexcept>
#include <boost/fusion/adapted/std_tuple.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/repository/include/qi_iter_pos.hpp>
namespace loloof64 {
namespace phx = boost::phoenix;
namespace qi = boost::spirit::qi;
/*
* This class has been taken from http://marko-editor.com/articles/position_tracking/
*/
template<typename Iterator>
struct CurrentPos {
CurrentPos() {
save_start_pos = qi::omit[boost::spirit::repository::qi::iter_pos[
phx::bind(&CurrentPos::setStartPos, this, qi::_1)]];
current_pos = boost::spirit::repository::qi::iter_pos[
qi::_val = phx::bind(&CurrentPos::getCurrentPos, this, qi::_1)];
}
qi::rule<Iterator> save_start_pos;
qi::rule<Iterator, std::size_t()> current_pos;
private:
void setStartPos(const Iterator &iterator) {
start_pos_ = iterator;
}
std::size_t getCurrentPos(const Iterator &iterator) {
return std::distance(start_pos_, iterator);
}
Iterator start_pos_;
};
enum result_t { white_won, black_won, draw, undecided };
struct pgn_tag {
std::string key;
std::string value;
};
struct game_move {
unsigned move_number;
std::string white_move;
std::string black_move;
result_t result;
};
struct pgn_game {
std::vector<pgn_tag> header;
std::vector<game_move> moves;
};
class PgnGamesExtractor {
public:
PgnGamesExtractor(std::string inputFilePath);
PgnGamesExtractor(std::istream &inputFile);
/*
Both constructos may throw PgnParsingException (if bad pgn format) and InputFileException (if missing file)
*/
std::vector<pgn_game> getGames() const { return games; }
virtual ~PgnGamesExtractor();
protected:
private:
std::vector<pgn_game> games;
void parseInput(std::istream &inputFile);
};
class PgnParsingException : public virtual std::runtime_error {
public:
PgnParsingException(std::string message) : std::runtime_error(message) {}
};
class InputFileException : public virtual std::runtime_error {
public:
InputFileException(std::string message) : std::runtime_error(message) {}
};
}
#endif // PGNGAMESEXTRACTOR_HPP
我没有post编译错误，因为编译错误太多了，而且文件很容易测试。
按照 this Sehe video tutorial 解决了问题
另外，应该注意到，这次他使用 boost::iostreams::mapped_file_source 而不是像我一样使用 ifstream，这个过程真的加快了！所以这个过程不再需要进度条了。
当然，它不会很好地与流媒体界面一起使用。您可以保留起始迭代器，但是
你不会提前知道流长度（除非你在带外获得它）
每次都计算当前位置（与起始迭代器的距离）将会非常低效。
既然你在评论中提到你正在解析文件，你应该考虑使用内存映射（boost::iostream::mapped_file_source 或 mmap 例如）。这样，距离计算是瞬时的，在随机访问迭代器上使用指针算法。
这是一个工作示例，具有以下 changes/notes:
- 使用内存映射输入数据3
omit[] in save_start_pos 没用（没有声明的属性）getCurrentPos 效率极低（在某种程度上，仅在 full_move 规则中使用 omit[current_pos] 会使解析速度降低几个数量级。
This is because boost::spirit::istream_iterator holds on to all previously read state in a deque and traversing them doesn't come for free when doing std::distance
您的 CurrentPos<Iterator> filepos; 实例在构造后超出范围！这意味着调用 save_start_pos/current_pos 是 Undefined Behaviour¹。将其移出构造函数。
您更改了某些规则的类型以包含位置信息以及 AST 类型。这既不必要又有缺陷：AST 类型与规则的 tuple<size_t, T> 版本不兼容。
此外，例如games 规则甚至没有公开位置，因为 save_start_pos 综合了 unused_type（无属性）。
所以，放弃整个元组业务，只处理语义操作中 filepos 成员的状态：
full_move %=
omit[filepos.current_pos [ reportProgress(_1) ]] >>
uint_
>> (lexeme["..." >> attr(no_move)] | "." >> single_move)
>> (single_move | attr(no_move))
>> -result;
最后，作为如何报告严格增加的进度指示²的演示，我包括了一个简单的凤凰演员：
struct reportProgress_f {
size_t total_;
mutable double pct = 0.0;
reportProgress_f(size_t total) : total_(total) {}
template<typename T>
void operator()(T pos) const {
double newpct = pos * 100.0 / total_;
if ((newpct - pct) > 10) {
//sleep(1); // because it's way too fast otherwise...
pct = newpct;
std::cerr << "\rProgress " << std::fixed << std::setprecision(1) << pct << std::flush;
};
}
};
phx::function<reportProgress_f> reportProgress;
Note reportProgress needs to be constructed with knowledge about start and end iterators, see the constructor for pgn_parser
¹ 在 the recorded live stream 中你可以看到我在第一次阅读时发现了错误，然后在我编译之后忘记了。程序崩溃了，尽职尽责:)然后我想起来了。
²即使面对回溯
3（不是严格要求，但我想目标不是简单地让它变得如此缓慢，你真的需要进度指示器吗？）
#ifndef PGNGAMESEXTRACTOR_HPP
#define PGNGAMESEXTRACTOR_HPP
#include <string>
#include <vector>
#include <fstream>
#include <stdexcept>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/spirit/repository/include/qi_iter_pos.hpp>
namespace loloof64 {
namespace phx = boost::phoenix;
namespace qi = boost::spirit::qi;
namespace qr = boost::spirit::repository::qi;
/*
* This class has been taken from http://marko-editor.com/articles/position_tracking/
*/
template<typename Iterator>
struct CurrentPos {
CurrentPos() {
save_start_pos = qr::iter_pos [phx::bind(&CurrentPos::setStartPos, this, qi::_1)] >> qi::eps;
current_pos = qr::iter_pos [qi::_val = phx::bind(&CurrentPos::getCurrentPos, this, qi::_1)] >> qi::eps;
}
qi::rule<Iterator> save_start_pos;
qi::rule<Iterator, std::size_t()> current_pos;
private:
void setStartPos(const Iterator &iterator) {
start_pos_ = iterator;
}
std::size_t getCurrentPos(const Iterator &iterator) {
return std::distance(start_pos_, iterator);
}
Iterator start_pos_;
};
enum result_t { white_won, black_won, draw, undecided };
struct pgn_tag {
std::string key;
std::string value;
};
struct game_move {
unsigned move_number;
std::string white_move;
std::string black_move;
result_t result;
};
struct pgn_game {
std::vector<pgn_tag> header;
std::vector<game_move> moves;
};
class PgnGamesExtractor {
public:
PgnGamesExtractor(std::string const& inputFilePath);
/*
Both constructos may throw PgnParsingException (if bad pgn format) and InputFileException (if missing file)
*/
std::vector<pgn_game> getGames() const { return games; }
virtual ~PgnGamesExtractor();
protected:
private:
std::vector<pgn_game> games;
void parseInput(std::string const&);
};
class PgnParsingException : public virtual std::runtime_error {
public:
PgnParsingException(std::string message) : std::runtime_error(message) {}
};
class InputFileException : public virtual std::runtime_error {
public:
InputFileException(std::string message) : std::runtime_error(message) {}
};
}
#endif // PGNGAMESEXTRACTOR_HPP
//#include "pgn_games_extractor.h"
#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <iostream>
#include <iomanip>
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_tag, key, value)
BOOST_FUSION_ADAPT_STRUCT(loloof64::game_move, move_number, white_move, black_move, result)
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_game, header, moves)
namespace loloof64 {
namespace qi = boost::spirit::qi;
template <typename Iterator> struct pgn_parser : qi::grammar<Iterator, std::vector<pgn_game>(), qi::space_type> {
pgn_parser(Iterator start, Iterator end)
: pgn_parser::base_type(games),
reportProgress(std::distance(start, end))
{
using namespace qi;
const std::string no_move;
result.add
("1-0", result_t::white_won)
("0-1", result_t::black_won)
("1/2-1/2", result_t::draw)
("*", result_t::undecided);
quoted_string = '"' >> *~char_('"') >> '"';
tag = '[' >> +alnum >> quoted_string >> ']';
header = +tag;
regular_move = lit("O-O-O") | "O-O" | (+char_("a-hNBRQK") >> +char_("a-h1-8x=NBRQK") >> -lit("e.p."));
single_move = raw [ regular_move >> -char_("+#") ];
full_move %=
omit[filepos.current_pos [ reportProgress(_1) ]] >>
uint_
>> (lexeme["..." >> attr(no_move)] | "." >> single_move)
>> (single_move | attr(no_move))
>> -result;
game_description = +full_move;
single_game = -header >> game_description;
games = filepos.save_start_pos >> *single_game;
BOOST_SPIRIT_DEBUG_NODES(
(tag)(header)(quoted_string)(regular_move)(single_move)
(full_move)(game_description)(single_game)(games)
)
}
private:
struct reportProgress_f {
size_t total_;
mutable double pct = 0.0;
reportProgress_f(size_t total) : total_(total) {}
template<typename T>
void operator()(T pos) const {
double newpct = pos * 100.0 / total_;
if ((newpct - pct) > 10) {
//sleep(1); // because it's way too fast otherwise...
pct = newpct;
std::cerr << "\rProgress " << std::fixed << std::setprecision(1) << pct << " " << std::flush;
};
}
};
phx::function<reportProgress_f> reportProgress;
CurrentPos<Iterator> filepos;
qi::rule<Iterator, pgn_tag(), qi::space_type> tag;
qi::rule<Iterator, std::vector<pgn_tag>, qi::space_type> header;
qi::rule<Iterator, game_move(), qi::space_type> full_move;
qi::rule<Iterator, std::vector<game_move>, qi::space_type> game_description;
qi::rule<Iterator, pgn_game(), qi::space_type> single_game;
qi::rule<Iterator, std::vector<pgn_game>(), qi::space_type> games;
// lexemes
qi::symbols<char, result_t> result;
qi::rule<Iterator, std::string()> quoted_string;
qi::rule<Iterator> regular_move;
qi::rule<Iterator, std::string()> single_move;
};
}
#include <boost/iostreams/device/mapped_file.hpp>
loloof64::PgnGamesExtractor::~PgnGamesExtractor() {
// dtor
}
loloof64::PgnGamesExtractor::PgnGamesExtractor(std::string const& inputFilePath) {
parseInput(inputFilePath);
}
void loloof64::PgnGamesExtractor::parseInput(std::string const& inputFilePath) {
boost::iostreams::mapped_file_source mf(inputFilePath);
//if (inputFile.fail() || inputFile.bad())
//throw new InputFileException("Could not read the input file !");
typedef char const* It;
std::vector<loloof64::pgn_game> temp_games;
/* It iter(inputFile >> std::noskipws), end; */
auto iter = mf.begin();
auto end = mf.end();
loloof64::pgn_parser<It> parser(iter, end);
//////////////////////////////////
//std::cout << "About to parse the file" << std::endl;
//////////////////////////////////
bool success = boost::spirit::qi::phrase_parse(iter, end, parser, boost::spirit::qi::space, temp_games);
//////////////////////////////////
//std::cout << "Finished to parse the file" << std::endl;
//////////////////////////////////
if (success && iter == end) {
games.swap(temp_games);
} else {
std::string error_fragment(iter, end);
throw PgnParsingException("Failed to parse the input at :'" + error_fragment + "' !");
}
}
int main() {
loloof64::PgnGamesExtractor pge("ScotchGambit.pgn");
std::cout << "Parsed " << pge.getGames().size() << " games\n";
for (auto& g : pge.getGames())
for (auto& m : g.moves)
std::cout << m.move_number << ".\t" << m.white_move << "\t" << m.black_move << "\n";
}
带有示例输出
Progress 32.6
Progress 44.5
Progress 55.5
Progress 67.2
Progress 77.2
Progress 89.1
Progress 100.0Parsed 1 games
1. e4 e5
2. Nf3 Nc6
3. d4 exd4
4. Bc4 Qf6
5. O-O d6
6. Ng5 Nh6
7. f4 Be7
8. e5 Qg6
9. exd6 cxd6
10. c3 dxc3
11. Nxc3 O-O
12. Nd5 Bd7
13. Rf3 Bg4
14. Bd3 Bxf3
15. Qxf3 f5
16. Bc4 Kh8
17. Nxe7 Nxe7
18. Qxb7 Qf6
19. Be3 Rfb8
20. Qd7 Rd8
21. Qb7 d5
22. Bb3 Nc6
23. Bxd5 Nd4
24. Rd1 Ne2+
25. Kf1 Rab8
26. Qxa7 Rxb2
27. Ne6 Qxe6
28. Bxe6 Rxd1+
29. Kf2
Note that on a terminal, the progress indication will self-update using a carriage-return instead of printing separate lines
使用 Boost Spirit 2 进行开发，我正在努力遵循 example in order to get progression (will add semantic actions later) in my pgn parser (see also
#include "pgn_games_extractor.h"
#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <tuple>
#include <iostream>
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_tag, key, value)
BOOST_FUSION_ADAPT_STRUCT(loloof64::game_move, move_number, white_move, black_move, result)
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_game, header, moves)
namespace loloof64 {
namespace qi = boost::spirit::qi;
typedef std::tuple<std::size_t, game_move> move_t;
typedef std::tuple<std::vector<pgn_tag>, std::vector<move_t>> game_t;
typedef std::tuple<std::size_t, std::vector<game_t>> pgn_t;
template <typename Iterator> struct pgn_parser : qi::grammar<Iterator, std::vector<pgn_game>, qi::space_type> {
pgn_parser() : pgn_parser::base_type(games) {
using namespace qi;
CurrentPos<Iterator> filepos;
const std::string no_move;
result.add
("1-0", result_t::white_won)
("0-1", result_t::black_won)
("1/2-1/2", result_t::draw)
("*", result_t::undecided);
quoted_string = '"' >> *~char_('"') >> '"';
tag = '[' >> +alnum >> quoted_string >> ']';
header = +tag;
regular_move = lit("O-O-O") | "O-O" | (+char_("a-hNBRQK") >> +char_("a-h1-8x=NBRQK") >> -lit("e.p."));
single_move = raw [ regular_move >> -char_("+#") ];
full_move = filepos.current_pos >> uint_
>> (lexeme["..." >> attr(no_move)] | "." >> single_move)
>> (single_move | attr(no_move))
>> -result;
game_description = +full_move;
single_game = -header >> game_description;
games = filepos.save_start_pos >> *single_game;
BOOST_SPIRIT_DEBUG_NODES(
(tag)(header)(quoted_string)(regular_move)(single_move)
(full_move)(game_description)(single_game)(games)
)
}
private:
qi::rule<Iterator, pgn_tag(), qi::space_type> tag;
qi::rule<Iterator, std::vector<pgn_tag>, qi::space_type> header;
qi::rule<Iterator, move_t(), qi::space_type> full_move;
qi::rule<Iterator, std::vector<move_t>, qi::space_type> game_description;
qi::rule<Iterator, game_t(), qi::space_type> single_game;
qi::rule<Iterator, pgn_t(), qi::space_type> games;
// lexemes
qi::symbols<char, result_t> result;
qi::rule<Iterator, std::string()> quoted_string;
qi::rule<Iterator> regular_move;
qi::rule<Iterator, std::string()> single_move;
};
}
loloof64::PgnGamesExtractor::PgnGamesExtractor(std::string inputFilePath) {
std::ifstream inputFile(inputFilePath);
parseInput(inputFile);
}
loloof64::PgnGamesExtractor::PgnGamesExtractor(std::istream &inputFile) { parseInput(inputFile); }
loloof64::PgnGamesExtractor::~PgnGamesExtractor() {
// dtor
}
void loloof64::PgnGamesExtractor::parseInput(std::istream &inputFile) {
if (inputFile.fail() || inputFile.bad())
throw new InputFileException("Could not read the input file !");
typedef boost::spirit::istream_iterator It;
loloof64::pgn_parser<It> parser;
std::vector<loloof64::pgn_game> temp_games;
It iter(inputFile >> std::noskipws), end;
//////////////////////////////////
std::cout << "About to parse the file" << std::endl;
//////////////////////////////////
bool success = boost::spirit::qi::phrase_parse(iter, end, parser, boost::spirit::qi::space, temp_games);
//////////////////////////////////
std::cout << "Finished to parse the file" << std::endl;
//////////////////////////////////
if (success && iter == end) {
games.swap(temp_games);
} else {
std::string error_fragment(iter, end);
throw PgnParsingException("Failed to parse the input at :'" + error_fragment + "' !");
}
}
和头文件：header.
#ifndef PGNGAMESEXTRACTOR_HPP
#define PGNGAMESEXTRACTOR_HPP
#include <string>
#include <vector>
#include <fstream>
#include <stdexcept>
#include <boost/fusion/adapted/std_tuple.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/repository/include/qi_iter_pos.hpp>
namespace loloof64 {
namespace phx = boost::phoenix;
namespace qi = boost::spirit::qi;
/*
* This class has been taken from http://marko-editor.com/articles/position_tracking/
*/
template<typename Iterator>
struct CurrentPos {
CurrentPos() {
save_start_pos = qi::omit[boost::spirit::repository::qi::iter_pos[
phx::bind(&CurrentPos::setStartPos, this, qi::_1)]];
current_pos = boost::spirit::repository::qi::iter_pos[
qi::_val = phx::bind(&CurrentPos::getCurrentPos, this, qi::_1)];
}
qi::rule<Iterator> save_start_pos;
qi::rule<Iterator, std::size_t()> current_pos;
private:
void setStartPos(const Iterator &iterator) {
start_pos_ = iterator;
}
std::size_t getCurrentPos(const Iterator &iterator) {
return std::distance(start_pos_, iterator);
}
Iterator start_pos_;
};
enum result_t { white_won, black_won, draw, undecided };
struct pgn_tag {
std::string key;
std::string value;
};
struct game_move {
unsigned move_number;
std::string white_move;
std::string black_move;
result_t result;
};
struct pgn_game {
std::vector<pgn_tag> header;
std::vector<game_move> moves;
};
class PgnGamesExtractor {
public:
PgnGamesExtractor(std::string inputFilePath);
PgnGamesExtractor(std::istream &inputFile);
/*
Both constructos may throw PgnParsingException (if bad pgn format) and InputFileException (if missing file)
*/
std::vector<pgn_game> getGames() const { return games; }
virtual ~PgnGamesExtractor();
protected:
private:
std::vector<pgn_game> games;
void parseInput(std::istream &inputFile);
};
class PgnParsingException : public virtual std::runtime_error {
public:
PgnParsingException(std::string message) : std::runtime_error(message) {}
};
class InputFileException : public virtual std::runtime_error {
public:
InputFileException(std::string message) : std::runtime_error(message) {}
};
}
#endif // PGNGAMESEXTRACTOR_HPP
我没有post编译错误，因为编译错误太多了，而且文件很容易测试。
按照 this Sehe video tutorial 解决了问题 另外，应该注意到，这次他使用 boost::iostreams::mapped_file_source 而不是像我一样使用 ifstream，这个过程真的加快了！所以这个过程不再需要进度条了。
当然，它不会很好地与流媒体界面一起使用。您可以保留起始迭代器，但是
你不会提前知道流长度（除非你在带外获得它）
每次都计算当前位置（与起始迭代器的距离）将会非常低效。
既然你在评论中提到你正在解析文件，你应该考虑使用内存映射（boost::iostream::mapped_file_source 或 mmap 例如）。这样，距离计算是瞬时的，在随机访问迭代器上使用指针算法。
这是一个工作示例，具有以下 changes/notes:
- 使用内存映射输入数据3
omit[]insave_start_pos没用（没有声明的属性）getCurrentPos效率极低（在某种程度上，仅在full_move规则中使用omit[current_pos]会使解析速度降低几个数量级。This is because
boost::spirit::istream_iteratorholds on to all previously read state in a deque and traversing them doesn't come for free when doingstd::distance您的
CurrentPos<Iterator> filepos;实例在构造后超出范围！这意味着调用save_start_pos/current_pos是 Undefined Behaviour¹。将其移出构造函数。您更改了某些规则的类型以包含位置信息以及 AST 类型。这既不必要又有缺陷：AST 类型与规则的
tuple<size_t, T>版本不兼容。此外，例如
games规则甚至没有公开位置，因为save_start_pos综合了unused_type（无属性）。所以，放弃整个元组业务，只处理语义操作中
filepos成员的状态：full_move %= omit[filepos.current_pos [ reportProgress(_1) ]] >> uint_ >> (lexeme["..." >> attr(no_move)] | "." >> single_move) >> (single_move | attr(no_move)) >> -result;最后，作为如何报告严格增加的进度指示²的演示，我包括了一个简单的凤凰演员：
struct reportProgress_f { size_t total_; mutable double pct = 0.0; reportProgress_f(size_t total) : total_(total) {} template<typename T> void operator()(T pos) const { double newpct = pos * 100.0 / total_; if ((newpct - pct) > 10) { //sleep(1); // because it's way too fast otherwise... pct = newpct; std::cerr << "\rProgress " << std::fixed << std::setprecision(1) << pct << std::flush; }; } }; phx::function<reportProgress_f> reportProgress;Note
reportProgressneeds to be constructed with knowledge about start and end iterators, see the constructor forpgn_parser
¹ 在 the recorded live stream 中你可以看到我在第一次阅读时发现了错误，然后在我编译之后忘记了。程序崩溃了，尽职尽责:)然后我想起来了。
²即使面对回溯
3（不是严格要求，但我想目标不是简单地让它变得如此缓慢，你真的需要进度指示器吗？）
#ifndef PGNGAMESEXTRACTOR_HPP
#define PGNGAMESEXTRACTOR_HPP
#include <string>
#include <vector>
#include <fstream>
#include <stdexcept>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/spirit/repository/include/qi_iter_pos.hpp>
namespace loloof64 {
namespace phx = boost::phoenix;
namespace qi = boost::spirit::qi;
namespace qr = boost::spirit::repository::qi;
/*
* This class has been taken from http://marko-editor.com/articles/position_tracking/
*/
template<typename Iterator>
struct CurrentPos {
CurrentPos() {
save_start_pos = qr::iter_pos [phx::bind(&CurrentPos::setStartPos, this, qi::_1)] >> qi::eps;
current_pos = qr::iter_pos [qi::_val = phx::bind(&CurrentPos::getCurrentPos, this, qi::_1)] >> qi::eps;
}
qi::rule<Iterator> save_start_pos;
qi::rule<Iterator, std::size_t()> current_pos;
private:
void setStartPos(const Iterator &iterator) {
start_pos_ = iterator;
}
std::size_t getCurrentPos(const Iterator &iterator) {
return std::distance(start_pos_, iterator);
}
Iterator start_pos_;
};
enum result_t { white_won, black_won, draw, undecided };
struct pgn_tag {
std::string key;
std::string value;
};
struct game_move {
unsigned move_number;
std::string white_move;
std::string black_move;
result_t result;
};
struct pgn_game {
std::vector<pgn_tag> header;
std::vector<game_move> moves;
};
class PgnGamesExtractor {
public:
PgnGamesExtractor(std::string const& inputFilePath);
/*
Both constructos may throw PgnParsingException (if bad pgn format) and InputFileException (if missing file)
*/
std::vector<pgn_game> getGames() const { return games; }
virtual ~PgnGamesExtractor();
protected:
private:
std::vector<pgn_game> games;
void parseInput(std::string const&);
};
class PgnParsingException : public virtual std::runtime_error {
public:
PgnParsingException(std::string message) : std::runtime_error(message) {}
};
class InputFileException : public virtual std::runtime_error {
public:
InputFileException(std::string message) : std::runtime_error(message) {}
};
}
#endif // PGNGAMESEXTRACTOR_HPP
//#include "pgn_games_extractor.h"
#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <iostream>
#include <iomanip>
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_tag, key, value)
BOOST_FUSION_ADAPT_STRUCT(loloof64::game_move, move_number, white_move, black_move, result)
BOOST_FUSION_ADAPT_STRUCT(loloof64::pgn_game, header, moves)
namespace loloof64 {
namespace qi = boost::spirit::qi;
template <typename Iterator> struct pgn_parser : qi::grammar<Iterator, std::vector<pgn_game>(), qi::space_type> {
pgn_parser(Iterator start, Iterator end)
: pgn_parser::base_type(games),
reportProgress(std::distance(start, end))
{
using namespace qi;
const std::string no_move;
result.add
("1-0", result_t::white_won)
("0-1", result_t::black_won)
("1/2-1/2", result_t::draw)
("*", result_t::undecided);
quoted_string = '"' >> *~char_('"') >> '"';
tag = '[' >> +alnum >> quoted_string >> ']';
header = +tag;
regular_move = lit("O-O-O") | "O-O" | (+char_("a-hNBRQK") >> +char_("a-h1-8x=NBRQK") >> -lit("e.p."));
single_move = raw [ regular_move >> -char_("+#") ];
full_move %=
omit[filepos.current_pos [ reportProgress(_1) ]] >>
uint_
>> (lexeme["..." >> attr(no_move)] | "." >> single_move)
>> (single_move | attr(no_move))
>> -result;
game_description = +full_move;
single_game = -header >> game_description;
games = filepos.save_start_pos >> *single_game;
BOOST_SPIRIT_DEBUG_NODES(
(tag)(header)(quoted_string)(regular_move)(single_move)
(full_move)(game_description)(single_game)(games)
)
}
private:
struct reportProgress_f {
size_t total_;
mutable double pct = 0.0;
reportProgress_f(size_t total) : total_(total) {}
template<typename T>
void operator()(T pos) const {
double newpct = pos * 100.0 / total_;
if ((newpct - pct) > 10) {
//sleep(1); // because it's way too fast otherwise...
pct = newpct;
std::cerr << "\rProgress " << std::fixed << std::setprecision(1) << pct << " " << std::flush;
};
}
};
phx::function<reportProgress_f> reportProgress;
CurrentPos<Iterator> filepos;
qi::rule<Iterator, pgn_tag(), qi::space_type> tag;
qi::rule<Iterator, std::vector<pgn_tag>, qi::space_type> header;
qi::rule<Iterator, game_move(), qi::space_type> full_move;
qi::rule<Iterator, std::vector<game_move>, qi::space_type> game_description;
qi::rule<Iterator, pgn_game(), qi::space_type> single_game;
qi::rule<Iterator, std::vector<pgn_game>(), qi::space_type> games;
// lexemes
qi::symbols<char, result_t> result;
qi::rule<Iterator, std::string()> quoted_string;
qi::rule<Iterator> regular_move;
qi::rule<Iterator, std::string()> single_move;
};
}
#include <boost/iostreams/device/mapped_file.hpp>
loloof64::PgnGamesExtractor::~PgnGamesExtractor() {
// dtor
}
loloof64::PgnGamesExtractor::PgnGamesExtractor(std::string const& inputFilePath) {
parseInput(inputFilePath);
}
void loloof64::PgnGamesExtractor::parseInput(std::string const& inputFilePath) {
boost::iostreams::mapped_file_source mf(inputFilePath);
//if (inputFile.fail() || inputFile.bad())
//throw new InputFileException("Could not read the input file !");
typedef char const* It;
std::vector<loloof64::pgn_game> temp_games;
/* It iter(inputFile >> std::noskipws), end; */
auto iter = mf.begin();
auto end = mf.end();
loloof64::pgn_parser<It> parser(iter, end);
//////////////////////////////////
//std::cout << "About to parse the file" << std::endl;
//////////////////////////////////
bool success = boost::spirit::qi::phrase_parse(iter, end, parser, boost::spirit::qi::space, temp_games);
//////////////////////////////////
//std::cout << "Finished to parse the file" << std::endl;
//////////////////////////////////
if (success && iter == end) {
games.swap(temp_games);
} else {
std::string error_fragment(iter, end);
throw PgnParsingException("Failed to parse the input at :'" + error_fragment + "' !");
}
}
int main() {
loloof64::PgnGamesExtractor pge("ScotchGambit.pgn");
std::cout << "Parsed " << pge.getGames().size() << " games\n";
for (auto& g : pge.getGames())
for (auto& m : g.moves)
std::cout << m.move_number << ".\t" << m.white_move << "\t" << m.black_move << "\n";
}
带有示例输出
Progress 32.6
Progress 44.5
Progress 55.5
Progress 67.2
Progress 77.2
Progress 89.1
Progress 100.0Parsed 1 games
1. e4 e5
2. Nf3 Nc6
3. d4 exd4
4. Bc4 Qf6
5. O-O d6
6. Ng5 Nh6
7. f4 Be7
8. e5 Qg6
9. exd6 cxd6
10. c3 dxc3
11. Nxc3 O-O
12. Nd5 Bd7
13. Rf3 Bg4
14. Bd3 Bxf3
15. Qxf3 f5
16. Bc4 Kh8
17. Nxe7 Nxe7
18. Qxb7 Qf6
19. Be3 Rfb8
20. Qd7 Rd8
21. Qb7 d5
22. Bb3 Nc6
23. Bxd5 Nd4
24. Rd1 Ne2+
25. Kf1 Rab8
26. Qxa7 Rxb2
27. Ne6 Qxe6
28. Bxe6 Rxd1+
29. Kf2
Note that on a terminal, the progress indication will self-update using a carriage-return instead of printing separate lines