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我是使用qi的新手,遇到了困難。我想解析等的輸入:使用boost解析兩個字符串向量:qi
X + Y + Z,A + B
成字符串的兩個向量。
我有代碼這樣做,但只有當語法解析單個字符。理想情況下,以下行應該是可讀的:
曦+葉+鄒敖+碧
使用簡單的更換,如elem = +(char_ - '+') % '+'
無法解析,因爲它會消耗「」第一ELEM,但我還沒有找到一個簡單的方法來解決這個問題。
這是我的單字符代碼,以供參考:
#include <bits/stdc++.h>
#define BOOST_SPIRIT_DEBUG
#include <boost/fusion/adapted.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
namespace qi = boost::spirit::qi;
namespace phx = boost::phoenix;
typedef std::vector<std::string> element_array;
struct reaction_t
{
element_array reactants;
element_array products;
};
BOOST_FUSION_ADAPT_STRUCT(reaction_t, (element_array, reactants)(element_array, products))
template<typename Iterator>
struct reaction_parser : qi::grammar<Iterator,reaction_t(),qi::blank_type>
{
reaction_parser() : reaction_parser::base_type(reaction)
{
using namespace qi;
elem = char_ % '+';
reaction = elem >> ',' >> elem;
BOOST_SPIRIT_DEBUG_NODES((reaction)(elem));
}
qi::rule<Iterator, reaction_t(), qi::blank_type> reaction;
qi::rule<Iterator, element_array(), qi::blank_type> elem;
};
int main()
{
const std::string input = "X + Y + Z, A + B";
auto f = begin(input), l = end(input);
reaction_parser<std::string::const_iterator> p;
reaction_t data;
bool ok = qi::phrase_parse(f, l, p, qi::blank, data);
if (ok) std::cout << "success\n";
else std::cout << "failed\n";
if (f!=l)
std::cout << "Remaining unparsed: '" << std::string(f,l) << "'\n";
}