Re: [Boost-users] [Spirit]Kleene star with arguments having optional attributes.

I've suddenly found a solution like this: *((qi::char_ - 'p') >> qi::omit[*qi::lit('p')]) But nevertheless it is interesting for me why my first attempt was wrong and how should I understand its behavior. Thanks. On 24 November 2010 13:06, Paul Graphov wrote:

Hello Boost Users,

I'm now building configuration file parser with Boost.Spirit. I have a little trouble understanding how this parser builds attribute:

It was supposed to parse strings throwing 'p' letter away.

*((qi::char_ - 'p') | qi::lit('p'))

attribute of qi::lit is Unused. attribute of (qi::char_ - 'p') is char.

so attribute of ((qi::char_ - 'p') | qi::lit('p')) should be optional<char> that is uninitialized optional value when matched against character 'p'

After applying Kleene star it should became vector. It seems to be compatible with string (at least it compiles). But 'p' letters are not thrown away.

The full example is here: http://pastebin.com/tCMw22Zy

The output of that example is: Full parsing Result: "abcpppdef"

Is it possible to make such a parser without using semantic actions like [bind(&string::append, res, _1)] or something like that, which seem to be less elegant solution.

Thanks!