问题描述
目前，我正在试图让使用的boost ::精神::齐:: phrase_parse 做了一些工作，但我不能靠自己想出解决办法。
I'm currently trying to get some work done using boost::spirit::qi::phrase_parse but I'm not able to figure this out by myself.
值得一提：我完全新的提高，因此提高::精神
Worth mentioning: I'm totally new to boost and so to boost::spirit.
我得到表单的输入{A [BC] - ＆GT; F [DE]，C - ＆GT; E，B-＆GT; Z}
我想这种类型的输入解析为的std ::地图＆LT;的std ::字符串，性病::字符串＆GT; 。关键应持有每的std :: string的在 - ＆gt;中和每一个值的std :: string的的 - ＆gt;中直到，发生。
I'd like to parse this type of input into a std::map<std::string, std::string>. The key should hold every std::string before the "->" and the value every std::string after the "->" until the ',' occurs.
此外，'['和]不宜存放。
所以性病的内容::地图应该是这样解析成功后：
So the content of the std::map should be something like this after the parsing succeeded:
{
("A", "F"),
("A", "D E"),
("B C", "F"),
("B C", "D E"),
("C", "E"),
("B", "Z")
}
我的第一种方法是将所有键/值存储在一个的std ::矢量＆lt;标准::字符串方式＆gt;
#include <boost/spirit/include/qi.hpp>
#include <iostream>
#include <string>
#include <vector>
int main()
{
using boost::spirit::qi::phrase_parse;
using boost::spirit::qi::char_;
using boost::spirit::qi::lexeme;
std::string input = "{A [B C] -> F [D E], C ->E,B->Z}";
std::string::const_iterator beg = input.begin(), end = input.end();
std::vector<std::string> sdvec;
bool r = phrase_parse( beg,
end,
'{' >> (+(+char_("a-zA-Z0-9") | lexeme[('[' >> +char_("a-zA-Z0-9 ") >> ']')]) >> '-' >> '>' >> +(+char_("a-zA-Z0-9") | lexeme[('[' >> +char_("a-zA-Z0-9 ") >> ']')])) % ',' >> '}',
boost::spirit::ascii::space,
sdvec
);
if(beg != end) {
std::cout << "Parsing failed!" << std::endl;
} else {
std::cout << "Parsing succeeded!" << std::endl;
}
for(int i=0; i<sdvec.size(); i++) {
std::cout << i << ": " << sdvec[i] << std::endl;
}
return 0;
}
执行这个我越来越发现每个的std ::字符串为的std ::向量的条目
Parsing 2 succeeded!
0: A
1: B C
2: F
3: D E
4: C
5: E
6: B
7: Z
但我不知道如何将这些值解析为的std ::地图＆LT;的std ::字符串，性病::字符串＆GT; 使用的boost ::精神::齐:: phrase_parse 作为简单地更换一些抛出编译错误。
But I've no idea how to parse these values into a std::map<std::string, std::string> using boost::spirit::qi::phrase_parse as simply replacing throws some compiling errors.
编辑：
其实我发现的东西是相当我需要什么：http://boost-spirit.com/home/articles/qi-example/parsing-a-list-of-key-value-pairs-using-spirit-qi/
Actually I found something that's quite what I need: http://boost-spirit.com/home/articles/qi-example/parsing-a-list-of-key-value-pairs-using-spirit-qi/
我根据我的问题通过本文的code：
I adopted the code of this article according to my problem:
#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/std_pair.hpp>
#include <iostream>
#include <string>
#include <vector>
#include <map>
namespace qi = boost::spirit::qi;
template <typename Iterator>
struct keys_and_values
: qi::grammar<Iterator, std::map<std::string, std::string>()>
{
keys_and_values()
: keys_and_values::base_type(query)
{
query = '{' >> *qi::lit(' ') >> pair >> *(qi::lit(',') >> *qi::lit(' ') >> pair) >> *qi::lit(' ') >> '}';
pair = key >> -(*qi::lit(' ') >> "->" >> *qi::lit(' ') >> value);
key = +qi::char_("a-zA-Z0-9") | qi::lexeme[('[' >> +qi::char_("a-zA-Z0-9 ") >> ']')];
value = +qi::char_("a-zA-Z0-9") | qi::lexeme[('[' >> +qi::char_("a-zA-Z0-9 ") >> ']')];
}
qi::rule<Iterator, std::map<std::string, std::string>()> query;
qi::rule<Iterator, std::pair<std::string, std::string>()> pair;
qi::rule<Iterator, std::string()> key, value;
};
int main()
{
std::string input = "{AB -> CD, E -> F, G -> HI, [J K L] -> [M N O] }";
std::string::iterator begin = input.begin();
std::string::iterator end = input.end();
keys_and_values<std::string::iterator> p; // create instance of parser
std::map<std::string, std::string> m; // map to receive results
bool result = qi::phrase_parse(begin, end, p, boost::spirit::ascii::space, m); // returns true if successful
if(begin != end) {
std::cout << "Parsing failed!" << std::endl;
} else {
std::cout << "Parsing succeeded!" << std::endl;
}
std::cout << m["AB"] << "\t" << m["E"] << "\t" << m["G"] << "\t" << m["J K L"] << std::endl;
return 0;
}
这样做的结果是多还是少了什么，我需要：
The result of this is more or less what I need:
Parsing succeeded!
CD F HI M N O
我来解决最后的问题就是像 A [B C]的情况 - ＆GT; F [D E] 。
什么办法让那些四分开键 - 值对（A，F），（A，DE），（BC，F） （BC，DE）进入我的的std ::地图＆LT;的std ::字符串，性病::字符串＆GT;米？
Any way to get those as four separated key-value pairs ("A", "F"), ("A", "D E"), ("B C", "F"), ("B C", "D E") into my std::map<std::string, std::string> m?
或者，也许更容易把它解析为的std ::地图＆LT;的std ::矢量＆lt;标准::字符串＆gt;中的std ::矢量＆lt;标准::字符串＆GT; ＆GT; ，其中每个的std ::矢量＆lt;标准::字符串＆GT; 持有的所有键/值
Or maybe it's easier to parse it into a std::map<std::vector<std::string>, std::vector<std::string> > where each std::vector<std::string> holds all keys/values?
例如：
in: "{A [B C] -> F [D E], C ->E,B->Z}"
out: { ({"A", "B C"}, {"F", "D E"}), ({"C"}, {"E"}), ({"B"}, {"Z"}) }
感谢您的帮助！
推荐答案
我觉得你很接近你的目标，所以我会跳过组合的一部分:-)
解析器会做它应该做的事情......检查语法和来标记数据然后将其传递键，值和输出图（多重映射）参数成凤功能插入在那里你可以插入任何在您需要的地图（多重映射）
I think you are quite close to your goal so I will skip the combinatorial part :-)The parser will do the things it is supposed to do ... to check the syntax and to tokenize data then it passes keys, values and output map ( multimap ) arguments into phoenix function inserter where you can insert whatever you need in your map ( multimap )
#if __cplusplus >= 201103L
#define BOOST_RESULT_OF_USE_DECLTYPE
#endif
#define BOOST_SPIRIT_USE_PHOENIX_V3
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <iostream>
#include <algorithm>
#include <iterator>
#include <iomanip>
#include <vector>
#include <map>
namespace qi = boost::spirit::qi;
namespace ascii=boost::spirit::ascii;
typedef std::map< std::string,std::string > TMap;
//typedef std::multimap< std::string,std::string > TMap;
struct SMapInsert
{
template <typename Arg1,typename Arg2,typename Arg3>
struct result
{
typedef void type;
};
template <typename Arg1,typename Arg2,typename Arg3>
void operator()( Arg1&out, Arg2&keys, Arg3&vals ) const
{
std::cout << "Keys:" << std::endl;
for( const auto &key : keys )
std::cout << std::left << "`" << key << "`" << std::endl;
std::cout << "Vals:" << std::endl;
for( const auto &val : vals )
std::cout << std::left << "`" << val << "`" << std::endl;
// your map here...
// out.insert
}
};
boost::phoenix::function< SMapInsert > inserter;
int main()
{
std::string input = "{A [B C] -> F [D E], C ->E,B->Z}";
TMap data;
std::string::const_iterator iter = input.begin();
std::string::const_iterator last = input.end();
qi::rule< std::string::const_iterator,std::string() > token=+qi::alnum;
qi::rule< std::string::const_iterator,ascii::space_type,std::vector< std::string >() >
keyOrvalue = +( token | ( '[' >> qi::lexeme[ +qi::char_("a-zA-Z0-9 ") ] >> ']' ) );
qi::rule< std::string::const_iterator,ascii::space_type, TMap() >
root = '{' >> ( ( keyOrvalue >> "->" >> keyOrvalue )[ inserter( qi::_val, qi::_1, qi::_2 ) ] ) % ',' >> '}';
std::cout << "input: `" << input << "`" << std::endl;
if( qi::phrase_parse( iter, last, root, ascii::space, data ) && iter==last )
{
for( const auto &keyValue : data )
std::cout << std::left << std::setw(10) << keyValue.first << std::setw(10) << keyValue.second << std::endl;
}
else
std::cout << "parsing failed:" << std::string( iter,last ) << std::endl;
return 0;
}
这篇关于在一个std ::地图＆LT店价值;的std ::字符串，性病::字符串＆GT;使用boost ::精神::齐:: phrase_parse的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！