无法解析使用boost::spirit::qi的SQL类型

我可能会问一个非常微不足道的问题，但我并没有从我的大脑中得到什么来破解它。尝试解析如下所示的SQL类where子句，使用boost::spirit::qi生成一对向量

std::string input = "book.author_id = '1234' and book.isbn = 'xy99' and book.type = 'abc' and book.lang = 'Eng'"

我已经通过以下线程，但仍然无法做到这一点:-(Thread5 Thread4Thread3Thread2Thread1

[Thread1][6]
[Thread2][7]
[Thread3][8]
[Thread4][9]
[Thread5][10]

我真诚地请求，请帮助我了解如何实现这一目标…也许我没有完全给我的100%，但请善良....

下面是完整的代码(我想做的部分注释)，作为第一步，我只是检查我是否可以在Vector中获得所有令牌，然后解析每个Vector元素以生成std::pair的另一个Vector

#include <boost/fusion/adapted.hpp>
#include <boost/spirit/include/qi.hpp>
#include <map>
#include <vector>
namespace qi    = boost::spirit::qi;
namespace phx   = boost::phoenix;
typedef std::string str_t;
typedef std::pair<str_t, str_t> pair_t;
typedef std::vector<pair_t> pairs_t;
typedef std::vector<str_t> strings_t;
//typedef std::map<std::string, std::string> map_t;
//typedef std::vector<map_t> maps_t;
template <typename It, typename Skipper = qi::space_type>
    //struct parser : qi::grammar<It, pairs_t(), Skipper>
    struct parser : qi::grammar<It, strings_t(), Skipper>
{
    parser() : parser::base_type(start)
    {
        using namespace qi;
        cond    = lexeme [ *(char_) ];
        conds   =  *(char_) >> cond % (lit("and"));
        //conds =  *(char_ - lit("and")) >>(cond % lit("and"));
        /*cond  = lexeme [ *(char_ - lit("and")) ];
        cond    = key >> "=" >> value;
        key     = *(char_ - "=");
        value   = (''' >> *(~char_(''')) >> ''');
        kv_pair = key >> value;*/
        start   = conds;
        //cond  = key >> "=" >> value;
        //key       = *(char_ - "=");
        //value = (''' >> *(~char_(''')) >> ''');
  //      kv_pair   = key >> value;
  //      start = kv_pair;
    }
  private:
    qi::rule<It, str_t(), Skipper> cond;
    qi::rule<It, strings_t(), Skipper> conds;
    //qi::rule<It, std::string(), Skipper> key, value;//, cond;
    //qi::rule<It, pair_t(), Skipper> kv_pair;
    //qi::rule<It, pairs_t(), Skipper> start;
    qi::rule<It, strings_t(), Skipper> start;
};
template <typename C, typename Skipper>
    bool doParse(const C& input, const Skipper& skipper)
{
    auto f(std::begin(input)), l(std::end(input));
    parser<decltype(f), Skipper> p;
    strings_t data;
    try
    {
        bool ok = qi::phrase_parse(f,l,p,skipper,data);
        if (ok)   
        {
            std::cout << "parse successn";
            std::cout << "No Of Key-Value Pairs=  "<<data.size()<<"n";
        }
        else    std::cerr << "parse failed: '" << std::string(f,l) << "'n";
        return ok;
    } 
    catch(const qi::expectation_failure<decltype(f)>& e)
    {
        std::string frag(e.first, e.last);
        std::cerr << e.what() << "'" << frag << "'n";
    }
    return false;
}
int main()
{
    std::cout<<"Pair Test n";
    const std::string input = "book.author_id = '1234' and book.isbn = 'xy99' and book.type = 'abc' and book.lang = 'Eng'";
    bool ok = doParse(input, qi::space);
    std::cout<< input <<"n";
    return ok? 0 : 255;
}

Pair Test
parse success
No Of Key-Value Pairs=  2
book.author_id = '1234' and book.isbn = 'xy99' and book.type = 'abc' and book.lang = 'Eng'

我期望4…因为有4个条件!!

提前感谢问候,Vivek

一些例子来解决- live on coliru