你为什么坚持指定[_val=_1]？这是多余的，因为默认属性传播会这样做。其实很痛，见下文
接下来，(def_first_line >> *def_subsequent_line) 的属性类型（显然）与std::vector<char> 不兼容。也许你可以
- 只需使用默认属性传播（它有足够的智能继续追加）
- 使用
raw[]获取完整匹配的输入
- 定义
BOOST_SPIRIT_ACTIONS_ALLOW_ATTR_COMPAT（我不确定这是否得到很好的支持）
还有，
更新
还有几个问题：
-
您拼错了大多数规则的属性类型（缺少()）：
qi::rule<Iterator, std::string()> comment_line;
qi::rule<Iterator, std::string()> empty_line;
qi::rule<Iterator, std::string()> def_first_line;
qi::rule<Iterator, std::string()> def_subsequent_line;
qi::rule<Iterator, std::string()> definition;
empty_line 与 eoi 匹配，导致输入结束时出现无限循环
-
char_ 的使用也接受空格（使用 graph 代替：）
def_first_line = graph >> +(char_ - eol) >> (eol|eoi);
使用qi::space 也会吃掉行尾！请改用qi::blank
-
有利于可靠性：
empty_line = *blank >> eol;
comment_line = *blank >> '#' >> *(char_ - eol) >> (eol|eoi);
def_first_line = graph >> +(char_ - eol) >> (eol|eoi);
def_subsequent_line = +blank >> +(char_ - eol) >> (eol|eoi);
definition = (def_first_line >> *def_subsequent_line);
start = (
*(comment_line | empty_line | definition)
) [ _val = px::construct<context>() ]
;
这个简单的习惯将节省您的工作时间和与 Spirit 一起工作时的理智。
您可以稍微简化一下包含
这是一个修正版本 Live On Coliru 输出：
<start>
<try># comment line\n\nfirs</try>
<comment_line>
<try># comment line\n\nfirs</try>
<success>\nfirst definition li</success>
<attributes>[[ , c, o, m, m, e, n, t, , l, i, n, e]]</attributes>
</comment_line>
<comment_line>
<try>\nfirst definition li</try>
<fail/>
</comment_line>
<empty_line>
<try>\nfirst definition li</try>
<success>first definition lin</success>
<attributes>[[]]</attributes>
</empty_line>
<comment_line>
<try>first definition lin</try>
<fail/>
</comment_line>
<empty_line>
<try>first definition lin</try>
<fail/>
</empty_line>
<definition>
<try>first definition lin</try>
<def_first_line>
<try>first definition lin</try>
<success> second \n third li</success>
<attributes>[[f, i, r, s, t, , d, e, f, i, n, i, t, i, o, n, , l, i, n, e]]</attributes>
</def_first_line>
<def_subsequent_line>
<try> second \n third li</try>
<success> third line\n\n# anot</success>
<attributes>[[f, i, r, s, t, , d, e, f, i, n, i, t, i, o, n, , l, i, n, e, , , s, e, c, o, n, d, ]]</attributes>
</def_subsequent_line>
<def_subsequent_line>
<try> third line\n\n# anot</try>
<success>\n# another comment l</success>
<attributes>[[f, i, r, s, t, , d, e, f, i, n, i, t, i, o, n, , l, i, n, e, , , s, e, c, o, n, d, , , , t, h, i, r, d, , l, i, n, e]]</attributes>
</def_subsequent_line>
<def_subsequent_line>
<try>\n# another comment l</try>
<fail/>
</def_subsequent_line>
<success>\n# another comment l</success>
<attributes>[[f, i, r, s, t, , d, e, f, i, n, i, t, i, o, n, , l, i, n, e, , , s, e, c, o, n, d, , , , t, h, i, r, d, , l, i, n, e]]</attributes>
</definition>
<comment_line>
<try>\n# another comment l</try>
<fail/>
</comment_line>
<empty_line>
<try>\n# another comment l</try>
<success># another comment li</success>
<attributes>[[]]</attributes>
</empty_line>
<comment_line>
<try># another comment li</try>
<success></success>
<attributes>[[ , a, n, o, t, h, e, r, , c, o, m, m, e, n, t, , l, i, n, e, !]]</attributes>
</comment_line>
<comment_line>
<try></try>
<fail/>
</comment_line>
<empty_line>
<try></try>
<fail/>
</empty_line>
<definition>
<try></try>
<def_first_line>
<try></try>
<fail/>
</def_first_line>
<fail/>
</definition>
<success></success>
<attributes>[]</attributes>
</start>
Success
完整代码供参考：
#define BOOST_SPIRIT_DEBUG
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <vector>
#include <iostream>
#include <string>
namespace qi = boost::spirit::qi;
namespace termcxx { namespace parser {
namespace ascii = boost::spirit::ascii;
namespace px = boost::phoenix;
//using qi::double_;
using ascii::blank;
//using px::ref;
using px::construct;
//using qi::eps;
//using qi::lit;
using qi::_val;
using qi::_1;
using ascii::char_;
using ascii::graph;
using qi::eol;
using qi::eoi;
struct context
{
int dummy;
context () = default;
context (context const &) = default;
context (std::vector<char> a) { }
context (std::vector<char> a, std::vector<char> b) { }
};
} }
BOOST_FUSION_ADAPT_STRUCT(termcxx::parser::context, (int, dummy))
namespace termcxx { namespace parser {
template <typename Iterator>
struct parser : qi::grammar<Iterator, context()>
{
parser() : parser::base_type(start)
{
empty_line = *blank >> eol;
comment_line = *blank >> '#' >> *(char_ - eol) >> (eol|eoi);
def_first_line = graph >> +(char_ - eol) >> (eol|eoi);
def_subsequent_line = +blank >> +(char_ - eol) >> (eol|eoi);
definition = (def_first_line >> *def_subsequent_line);
start = (
*(comment_line | empty_line | definition)
) [ _val = px::construct<context>() ]
;
BOOST_SPIRIT_DEBUG_NODES((start)(def_first_line)(def_subsequent_line)(definition)(empty_line)(comment_line))
}
private:
qi::rule<Iterator, context()> start;
qi::rule<Iterator, std::string()> comment_line;
qi::rule<Iterator, std::string()> empty_line;
qi::rule<Iterator, std::string()> def_first_line;
qi::rule<Iterator, std::string()> def_subsequent_line;
qi::rule<Iterator, std::string()> definition;
};
} }
int main()
{
using It = boost::spirit::istream_iterator;
termcxx::parser::parser<It> g;
It f(std::cin >> std::noskipws), l;
termcxx::parser::context data;
if (qi::parse(f,l,g,data))
std::cout << "Success\n";
else
std::cout << "Failure\n";
if (f != l)
std::cout << "Remaining input: '" << std::string(f,l) << "'\n";
}