无法在提升精神中指定船长(编译器错误）

Can not specify a skipper in boost spirit (compiler error)

本文关键字：船长 编译器 错误      更新时间：2023-10-16

我正在尝试使用boost::spirit构建一个解析器，除了其他东西之外，它还应该能够解析整数对，例如"（3,4）"。

我的代码正在工作，但我也想接受包含空格的对，即"（ 4 ， 6 ）"。尝试添加 space_type 船长（如提升精神教程中所示）时，以下代码无法编译。我看不到我正在犯的严重错误（我怀疑使用了错误的命名空间，但它似乎是正确的命名空间）。

#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/fusion/include/std_pair.hpp>
using namespace std;
using namespace boost::spirit::qi;
using position = std::pair<int,  int>;
template<typename Iterator>
struct position_grammar : grammar<Iterator, position(), boost::spirit::ascii::space_type> {
    position_grammar() : position_grammar::base_type(start) {
        start = lit("(") >> int_ >> lit(",") >> int_ >> lit(")");
    }
    rule<Iterator, position(),boost::spirit::ascii::space_type> start;
};
int main() {
    std::string s = "(1,2)";
    position_grammar<std::string::iterator> grammar;
    position p;
    bool r = parse(s.begin(), s.end(), grammar,p);
    cout << "parsing: " << r << " position: " << p.first << ", " << p.second << "n";
    return 0;
}

编译器输出：

In file included from /usr/include/boost/spirit/home/qi/nonterminal.hpp:14:0,
                 from /usr/include/boost/spirit/home/qi.hpp:21,
                 from /usr/include/boost/spirit/include/qi.hpp:16,
                 from /home/pansen/proggs/foo/src/foo/model/routing_parser_test.cpp:2:
/usr/include/boost/spirit/home/qi/nonterminal/rule.hpp: In instantiation of ‘bool boost::spirit::qi::rule<Iterator, T1, T2, T3, T4>::parse(Iterator&, const Iterator&, Context&, const Skipper&, Attribute&) const [with Context = boost::spirit::context<boost::fusion::cons<std::pair<int, int>&, boost::fusion::nil_>, boost::spirit::locals<> >; Skipper = boost::spirit::unused_type; Attribute = std::pair<int, int>; Iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; T1 = std::pair<int, int>(); T2 = boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>; T3 = boost::spirit::unused_type; T4 = boost::spirit::unused_type]’:
/usr/include/boost/spirit/home/qi/reference.hpp:43:72:   required from ‘bool boost::spirit::qi::reference<Subject>::parse(Iterator&, const Iterator&, Context&, const Skipper&, Attribute&) const [with Iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; Context = boost::spirit::context<boost::fusion::cons<std::pair<int, int>&, boost::fusion::nil_>, boost::spirit::locals<> >; Skipper = boost::spirit::unused_type; Attribute = std::pair<int, int>; Subject = const boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >, std::pair<int, int>(), boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type>]’
/usr/include/boost/spirit/home/qi/parse.hpp:86:82:   required from ‘bool boost::spirit::qi::parse(Iterator&, Iterator, const Expr&, Attr&) [with Iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; Expr = position_grammar<__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> > >; Attr = std::pair<int, int>]’
/usr/include/boost/spirit/home/qi/parse.hpp:98:25:   required from ‘bool boost::spirit::qi::parse(const Iterator&, Iterator, const Expr&, Attr&) [with Iterator = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >; Expr = position_grammar<__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> > >; Attr = std::pair<int, int>]’
/home/pansen/proggs/foo/src/foo/model/routing_parser_test.cpp:23:46:   required from here
/usr/include/boost/spirit/home/qi/nonterminal/rule.hpp:304:17: error: no match for call to ‘(const function_type {aka const boost::function<bool(__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >&, const __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >&, boost::spirit::context<boost::fusion::cons<std::pair<int, int>&, boost::fusion::nil_>, boost::fusion::vector0<> >&, const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >&)>}) (__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >&, const __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >&, boost::spirit::qi::rule<__gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >, std::pair<int, int>(), boost::proto::exprns_::expr<boost::proto::tagns_::tag::terminal, boost::proto::argsns_::term<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >, 0l>, boost::spirit::unused_type, boost::spirit::unused_type>::context_type&, const boost::spirit::unused_type&)’
                 if (f(first, last, context, skipper))
                 ^
In file included from /usr/include/boost/function/detail/maybe_include.hpp:33:0,
                 from /usr/include/boost/function/detail/function_iterate.hpp:14,
                 from /usr/include/boost/preprocessor/iteration/detail/iter/forward1.hpp:67,
                 from /usr/include/boost/function.hpp:64,
                 from /usr/include/boost/spirit/home/qi/nonterminal/rule.hpp:16,
                 from /usr/include/boost/spirit/home/qi/nonterminal.hpp:14,
                 from /usr/include/boost/spirit/home/qi.hpp:21,
                 from /usr/include/boost/spirit/include/qi.hpp:16,
                 from /home/pansen/proggs/foo/src/foo/model/routing_parser_test.cpp:2:
/usr/include/boost/function/function_template.hpp:767:17: note: candidate: boost::function4<R, T1, T2, T3, T4>::result_type boost::function4<R, T1, T2, T3, T4>::operator()(T0, T1, T2, T3) const [with R = bool; T0 = __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >&; T1 = const __gnu_cxx::__normal_iterator<char*, std::__cxx11::basic_string<char> >&; T2 = boost::spirit::context<boost::fusion::cons<std::pair<int, int>&, boost::fusion::nil_>, boost::fusion::vector0<> >&; T3 = const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >&; boost::function4<R, T1, T2, T3, T4>::result_type = bool]
     result_type operator()(BOOST_FUNCTION_PARMS) const
                 ^
/usr/include/boost/function/function_template.hpp:767:17: note:   no known conversion for argument 4 from ‘const boost::spirit::unused_type’ to ‘const boost::spirit::qi::char_class<boost::spirit::tag::char_code<boost::spirit::tag::space, boost::spirit::char_encoding::ascii> >&’

错误指向if (f(first, last, context, skipper))看起来像这里的错误（请参阅sehe的答案）。但是我已经正确指定了属性（至少我认为是这样）。

如果你想使用船长，你必须通过调用phrase_parse而不是parse来传递它的实例：

bool r = phrase_parse(s.begin(), s.end(), grammar, qi::space, p);

或者，您可以通过在包含无船长规则中声明船长来隐藏有关船长的详细信息skip(qi::space) [ real_start_rule_with_skipper ]

另请参阅：提升精神船长问题

笔记：

  • 不要使用using namespace - 尤其是不要同时使用std和boost::spirit::qi。您始终可以在本地使用 using namespace qi;

  • 无需将每个文字都包装在lit()中。以下是简化的规则：

    position_rule = '(' >> qi::int_ >> ',' >> qi::int_ >> ')';

演示

住在科里鲁

#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/std_pair.hpp>
namespace qi = boost::spirit::qi;
using position = std::pair<int, int>;
template <typename Iterator> struct position_grammar : qi::grammar<Iterator, position()> {
    position_grammar() : position_grammar::base_type(start) {
        position_rule = '(' >> qi::int_ >> ',' >> qi::int_ >> ')';
        start         = qi::skip(boost::spirit::ascii::space) [ position_rule ];
    }
    qi::rule<Iterator, position()> start;
    qi::rule<Iterator, position(), boost::spirit::ascii::space_type> position_rule;
};
int main() {
    std::string s = "  ( 1t,rn2 )";
    position_grammar<std::string::iterator> grammar;
    position p;
    bool r = parse(s.begin(), s.end(), grammar, p);
    std::cout << "parsing: " << r << " position: " << p.first << ", " << p.second << "n";
}

指纹

parsing: 1 position: 1, 2
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