Re: [Boost-users] Using boost Barser to extract data from string

Subject: Re: [Boost-users] Using boost Barser to extract data from string
From: Igor R (boost.lists_at_[hidden])
Date: 2011-11-14 07:07:13

>>>> I want to write parser for data I receive from a stock exchange server.
>>>> There is no delimeter that define different fields in buffer I receive.
>>>> However, it is provided in exchange spec's start and of each field.
>>>> How should I write parser for data I recveive? I am new to parser
>>>> consept and apprecite your suggestion.
>>>> I am putting following example data string just to insist my scenario
>>>>
>>>> Data my application recveive:
>>>> 1001TXPASSWORDSESSION1N
>>>>
>>>> I need to decode it(as per spec) as:
>>>> Messate type: 1001
>>>> UserID:Â Â Â Â Â Â Â Â Â Â Â  TX
>>>> password:Â Â Â Â Â Â Â  PASSWORD
>>>> session:Â Â Â Â Â Â Â Â Â Â  SESSION
>>>> data:Â Â Â Â Â Â Â Â Â Â Â Â Â Â  N
>>>>
>>>> How should I be doing it?

#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/include/adapt_struct.hpp>

using std::string;

struct message
{
  int type_;
  string userID_, password_, session_;
  char data_;
};

BOOST_FUSION_ADAPT_STRUCT
(
        message,
        (int, type_)
        (string, userID_)
        (string, password_)
        (string, session_)
        (char, data_)
)

int main()
{
  namespace qi = boost::spirit::qi;
  using qi::char_;
  using qi::repeat;
  string in = "1001TXPASSWORDSESSION1N";
  message out;
  bool res = qi::parse(in.begin(), in.end(),  qi::int_ >>
repeat(2)[char_] >> repeat(8)[char_] >> repeat(8)[char_] >> char_,
out);
}