Boost 从可选解析器表达式的可变列表生成Spirit解析器表达式
我正在寻找实现变量函数的最简单方法,它采用boost::spirit::qi规则列表,并将列表扩展为以下格式的表达式:rule1 | rule2 | rule3 |。。。。让我们假设规则不合成任何属性。非常感谢你的帮助Boost 从可选解析器表达式的可变列表生成Spirit解析器表达式,boost,c++11,boost-spirit,variadic-templates,boost-fusion,Boost,C++11,Boost Spirit,Variadic Templates,Boost Fusion,我正在寻找实现变量函数的最简单方法,它采用boost::spirit::qi规则列表,并将列表扩展为以下格式的表达式:rule1 | rule2 | rule3 |。。。。让我们假设规则不合成任何属性。非常感谢你的帮助 #include <boost/config/warning_disable.hpp> #include <boost/spirit/include/qi.hpp> #include <string> #include <iostream
#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <string>
#include <iostream>
#include <boost/spirit/include/phoenix_operator.hpp>
namespace qi = boost::spirit::qi;
namespace ph = boost::phoenix;
namespace ascii = boost::spirit::ascii;
using boost::spirit::qi::phrase_parse;
using boost::spirit::qi::ascii::space;
using boost::spirit::iso8859_1::char_;
typedef qi::rule<std::string::const_iterator,ascii::space_type> mrule_t;
typedef qi::rule< std::string::const_iterator,std::string() > wrule_t;
#包括
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#包括
名称空间qi=boost::spirit::qi;
名称空间ph=boost::phoenix;
名称空间ascii=boost::spirit::ascii;
使用boost::spirit::qi::短语解析;
使用boost::spirit::qi::ascii::space;
使用boost::spirit::iso8859_1::char_u1;
类型定义qi::规则规则;
typedef qi::rulewrule\t;
//如何推导expandBitwise()返回类型?
模板
按位扩展(T&T)
{
返回t.rule;
}
模板
按位扩展(T&T,尾部和…尾部)
{
返回t.rule 124;按位展开(尾部…);
}
结构TStruct
{
规则;
模板
TStruct(T&rVar,const std::string&name,R&rule):
规则(qi::lit(名称)>>规则[ph::ref(rVar)=qi::_1])
{}
};
模板
void mparse(常量标准::字符串和行、T&T、尾部和…尾部)
{
std::string::const_迭代器f,l;
f=行。开始();
l=line.end();
//我想在这里展开规则。。。
//if(短语解析(f,l,按位展开(t,tail…,空格)&&f==l)
if(短语解析(f,l,t.rule,space)&&f==l)
std::cout您意外地从expandBitwise
帮助程序返回了TStruct类型。请按如下方式修复它:
template<typename T>
auto expandBitwise(T const& t) -> decltype(t.rule_)
{
return t.rule_;
}
template<typename T,typename ...Tail>
auto expandBitwise(T const& t,Tail const&... tail) -> decltype(t.rule_)
{
return t.rule_ | expandBitwise(tail...);
}
诀窍在于:
shortopt = shortNames [_a = _1] >> lazy(_a);
longopt = longNames [_a = _1] >> lazy(_a);
其中shortNames
和longNames
是解析器的qi::symbols
表,基于CliOptions
和CliFlags
的可变列表动态构建(我将它们作为元组传递,因为我也想将结果存储在CliOption
结构中)
qi::lazy(_a)
调用存储在符号表中的解析器
另外,我的CliOptions解析器还具有生成“用法”信息的功能。解析表达式和用法信息的生成器是可扩展的
int main(int argc, char* argv[])
{
using CliParsing::make_option;
typedef std::string::const_iterator It;
auto config = std::make_tuple(
make_option('a', "absolutely", "absolutely"),
make_option('b', "borked" , "borked") ,
make_option('c', "completion", "completion"),
make_option('d', "debug", "turn on debugging"),
make_option('e', "", "no long name") ,
//make_option('f', "flungeons" , "flungeons") ,
//make_option('g', "goofing" , "") ,
//make_option('m', "monitor", "monitoring level"),
make_option('t', "testing" , "testing flags"),
make_option('\0',"file" , "with a filename (no short name)"),
make_option('y', "assume-yes", "always assume yes"),
make_option('v', "verbose", "increase verbosity level"),
make_option('i', "increment", "stepsize to increment with", 5)
);
CliParsing::OptionGrammar<It> parser(config);
using namespace phx::arg_names;
const auto cmdline = std::accumulate(argv+1, argv+argc, std::string(), arg1 + arg2 + '\0');
bool ok = qi::parse(begin(cmdline), end(cmdline), parser);
std::cout << "Parse success " << std::boolalpha << ok << "\n";
std::cout << parser.getUsage();
return ok? 0 : 255;
}
如您所见,尚未实现所有选项(值得注意的是,--
标记选项列表的末尾)
谢谢你的提示!我刚刚尝试了你的代码,除非我做错了什么…我得到以下输出:语法错误:abc 8.81已解析:-a atoken语法错误:-b btoken语法错误:-c ctoken语法错误:-d dtoken
–
好吧,所以,我不能离开它:/
事实证明,这涉及到未定义的行为,因为解析器表达式被传递到expandBitwise
并被复制的方式:Boost原型表达式模板不是为了被复制而设计的,因为它们可能包含对临时对象的引用,临时对象的生命周期在其包含完整数据的结束时结束-表情
有关更多背景信息,请参阅
在使用rule.alias()
和boost::proto::deepcopy
调整了很长(很长)时间后,我找到了以下解决方案(顺便说一句,它不再需要任何帮助函数):
使用此代码,瞧,输出变成:
Syntax error:abc 8.81
Remaining unparsed: 'abc 8.81'
Parsed:-a atoken
Parsed:-b btoken
Parsed:-c ctoken
Parsed:-d dtoken
Bye
作为奖励,该代码现在允许您使用Spirit的内置debug()功能(取消注释该行):
谢谢你的提示!我刚刚尝试了你的代码,除非我做错了什么…我得到以下输出:语法错误:abc 8.81解析:-a atoken语法错误:-b b Token语法错误:-c ctoken语法错误:-d dtokenWell,我不希望你需要帮助调试语法。我假设问题是关于获得你的expandBitwise
要编译的函数模板。您是否有时间了解Nabialek技巧(使用qi::symbols
而不是r1 | r2 | r3 | r4
表单的“可变”表达式)“猜中了:-”,我一直在研究命令行解析器。主要是作为一个练习来尝试与Boost精神和C++相关的各种各样的方法。非常感谢你和我分享你的代码片段!好,准备好投票!我花了3个小时调试你的语法。结果比你想的要棘手。详细说明我提出的解决方案和完整的解释。干杯。你今天让我精神振奋!再次感谢:-)BRAVISSIMO MAESTRO!非常感谢你没有放弃我,坚持我最初的规范!!!正如前面所说,我更关心原则和见解,而不是优雅的解决方法,但我也很欣赏其他选择:-)我昨天被这个问题困住了,你的“解决方案”让我进入了一些新的领域:-)我有没有提到我仍然非常推荐使用qi::symbols来解决这个问题?它不那么复杂,而且可能更具编译时/运行时效率(嗯,需要评测,但是谁评测了他的CLI参数解析器?这里更简单更有效)。我很想在以后的任务中玩弄一个合适的原型eDSL。我的待办事项列表中有qi::symbols练习(如您在第一个答案中所述)。此答案中使用的实现和工具将让我忙碌一段时间:-)
shortopt = shortNames [_a = _1] >> lazy(_a);
longopt = longNames [_a = _1] >> lazy(_a);
int main(int argc, char* argv[])
{
using CliParsing::make_option;
typedef std::string::const_iterator It;
auto config = std::make_tuple(
make_option('a', "absolutely", "absolutely"),
make_option('b', "borked" , "borked") ,
make_option('c', "completion", "completion"),
make_option('d', "debug", "turn on debugging"),
make_option('e', "", "no long name") ,
//make_option('f', "flungeons" , "flungeons") ,
//make_option('g', "goofing" , "") ,
//make_option('m', "monitor", "monitoring level"),
make_option('t', "testing" , "testing flags"),
make_option('\0',"file" , "with a filename (no short name)"),
make_option('y', "assume-yes", "always assume yes"),
make_option('v', "verbose", "increase verbosity level"),
make_option('i', "increment", "stepsize to increment with", 5)
);
CliParsing::OptionGrammar<It> parser(config);
using namespace phx::arg_names;
const auto cmdline = std::accumulate(argv+1, argv+argc, std::string(), arg1 + arg2 + '\0');
bool ok = qi::parse(begin(cmdline), end(cmdline), parser);
std::cout << "Parse success " << std::boolalpha << ok << "\n";
std::cout << parser.getUsage();
return ok? 0 : 255;
}
short form option --increment parsed
ignoring unparsed argument: '3'
long form switch --completion parsed
short form switch --testing parsed
long form switch --file parsed
ignoring unparsed argument: '=SOME.TXT'
short form switch --borked parsed
ignoring unparsed argument: 'huh?'
Parse success true
--absolutely (-a)
absolutely (flag)
--borked (-b)
borked (flag)
--completion (-c)
completion (flag)
--debug (-d)
turn on debugging (flag)
-e
no long name (flag)
--testing (-t)
testing flags (flag)
--file
with a filename (no short name) (flag)
--assume-yes (-y)
always assume yes (flag)
--verbose (-v)
increase verbosity level (flag)
--increment (-i)
stepsize to increment with (option with value; default '5')
template<typename ...Tail>
void mparse(const std::string& line,Tail& ...tail)
{
auto parser = boost::fusion::fold(
boost::tie(ph::bind(&TStruct::rule_, arg1)(tail)...),
qi::eps(false),
deepcopy_(arg2 | arg1)
);
auto f=begin(line), l=end(line);
if( qi::phrase_parse(f, l, parser, ascii::space ) )
std::cout << "Parsed:" << line << std::endl;
else
std::cout << "Syntax error:" << line << std::endl;
if (f!=l)
std::cout << "Remaining unparsed: '" << std::string(f,l) << "'\n";
}
struct DeepCopy
{
template<typename E> struct result { typedef typename boost::proto::result_of::deep_copy<E>::type type; };
template<typename E>
typename result<E>::type
operator()(E const& expr) const {
return boost::proto::deep_copy(expr);
}
};
static const ph::function<DeepCopy> deepcopy_;
Syntax error:abc 8.81
Remaining unparsed: 'abc 8.81'
Parsed:-a atoken
Parsed:-b btoken
Parsed:-c ctoken
Parsed:-d dtoken
Bye
<-d>
<try>abc 8.81</try>
<fail/>
</-d>
<-c>
<try>abc 8.81</try>
<fail/>
</-c>
<-b>
<try>abc 8.81</try>
<fail/>
</-b>
<-a>
<try>abc 8.81</try>
<fail/>
</-a>
Syntax error:abc 8.81
Remaining unparsed: 'abc 8.81'
#define BOOST_RESULT_OF_USE_DECLTYPE
#define BOOST_SPIRIT_USE_PHOENIX_V3
#include <boost/fusion/adapted/boost_tuple.hpp>
#include <boost/fusion/include/fold.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
namespace qi = boost::spirit::qi;
namespace ph = boost::phoenix;
namespace ascii = boost::spirit::ascii;
using namespace ph::arg_names;
typedef qi::rule<std::string::const_iterator,ascii::space_type> mrule_t;
typedef qi::rule<std::string::const_iterator,std::string() > wrule_t;
struct TStruct
{
mrule_t rule_;
template<typename T,typename R>
TStruct( T& rVar,const std::string&name, R& rule ) :
rule_( qi::lit(name) >> rule[ ph::ref(rVar) = qi::_1 ] )
{
rule_.name(name);
// debug(rule_);
}
};
struct DeepCopy
{
template<typename E> struct result { typedef typename boost::proto::result_of::deep_copy<E>::type type; };
template<typename E>
typename result<E>::type
operator()(E const& expr) const {
return boost::proto::deep_copy(expr);
}
};
static const ph::function<DeepCopy> deepcopy_;
template<typename ...Tail>
void mparse(const std::string& line,Tail& ...tail)
{
auto parser = boost::fusion::fold(
boost::tie(ph::bind(&TStruct::rule_, arg1)(tail)...),
qi::eps(false),
deepcopy_(arg2 | arg1)
);
auto f=begin(line), l=end(line);
if( qi::phrase_parse(f, l, parser, ascii::space ) )
std::cout << "Parsed:" << line << std::endl;
else
std::cout << "Syntax error:" << line << std::endl;
if (f!=l)
std::cout << "Remaining unparsed: '" << std::string(f,l) << "'\n";
}
int main()
{
wrule_t rword=+~ascii::space;
std::string par1,par2,par3,par4;
TStruct r1( par1, "-a", rword );
TStruct r2( par2, "-b", rword );
TStruct r3( par3, "-c", rword );
TStruct r4( par4, "-d", rword );
mparse("abc 8.81" ,r1,r2,r3,r4);
mparse("-a atoken" ,r1,r2,r3,r4);
mparse("-b btoken" ,r1,r2,r3,r4);
mparse("-c ctoken" ,r1,r2,r3,r4);
mparse("-d dtoken" ,r1,r2,r3,r4);
std::cout << "Bye\n";
}