提高精神难度，从XML示例工作
boost spirit difficulty, working from XML example
我正在尝试学习提升精神库。从 qi/karma XML 示例 (http://www.boost.org/doc/libs/1_50_0/libs/spirit/repository/example/karma/mini_xml_karma_sr.cpp( 开始，我尝试将 mini_xml 中的子容器更改为 std：：vector 以外的内容(在本例中为 std：：list，请在下面查找 mini_xml_children typedef(。不幸的是，这样做似乎无法编译。
编译错误似乎表明 phoenix 正在尝试将 std：：list 分配给 std：：vector，我在解释这个问题时遇到了一点麻烦，因为我的代码中不再有任何对 std：：vector 的引用。我做了一些挖掘 - 看起来像 boost：：spirit：：karma：：action：：generate 决定在内部使用 std：：vector，而不是检测mini_xml使用的容器。
如果我的假设是正确的，我认为我需要一种更明确地传达"属性"应该是什么的方法。有没有简单的方法可以做到这一点？理想情况下，我希望这段代码与容器无关。
代码：
#include <boost/config/warning_disable.hpp>
#include <boost/spirit/include/qi.hpp>
//[mini_xml_karma_sr_includes
#include <boost/spirit/include/karma.hpp>
#include <boost/spirit/repository/include/karma_subrule.hpp>
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/include/phoenix_operator.hpp>
#include <boost/spirit/include/phoenix_fusion.hpp>
//]
#include <boost/spirit/include/phoenix_function.hpp>
#include <boost/spirit/include/phoenix_stl.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <boost/variant/recursive_variant.hpp>
#include <iostream>
#include <fstream>
#include <string>
//[mini_xml_karma_sr_using
using namespace boost::spirit;
using namespace boost::spirit::ascii;
namespace repo = boost::spirit::repository;
//]
namespace fusion = boost::fusion;
namespace phoenix = boost::phoenix;
using phoenix::at_c;
using phoenix::push_back;
///////////////////////////////////////////////////////////////////////////////
// Our mini XML tree representation
///////////////////////////////////////////////////////////////////////////////
struct mini_xml;
typedef
boost::variant<
boost::recursive_wrapper<mini_xml>
, std::string
>
mini_xml_node;
//typedef std::vector<mini_xml_node> mini_xml_children; // original
typedef std::list<mini_xml_node> mini_xml_children;
struct mini_xml
{
std::string name; // tag name
mini_xml_children children; // children
};
// We need to tell fusion about our mini_xml struct
// to make it a first-class fusion citizen
BOOST_FUSION_ADAPT_STRUCT(
mini_xml,
(std::string, name)
(mini_xml_children, children)
)
///////////////////////////////////////////////////////////////////////////////
// Our mini XML grammar definition
///////////////////////////////////////////////////////////////////////////////
template <typename Iterator>
struct mini_xml_parser :
qi::grammar<Iterator, mini_xml(), space_type>
{
mini_xml_parser() : mini_xml_parser::base_type(xml)
{
text = lexeme[+(char_ - '<') [_val += _1]];
node = (xml | text) [_val = _1];
start_tag =
'<'
>> !lit('/')
>> lexeme[+(char_ - '>') [_val += _1]]
>> '>'
;
end_tag =
"</"
>> lit(_r1)
>> '>'
;
xml =
start_tag [at_c<0>(_val) = _1]
>> *node [push_back(at_c<1>(_val), _1)]
>> end_tag(at_c<0>(_val))
;
}
qi::rule<Iterator, mini_xml(), space_type> xml;
qi::rule<Iterator, mini_xml_node(), space_type> node;
qi::rule<Iterator, std::string(), space_type> text;
qi::rule<Iterator, std::string(), space_type> start_tag;
qi::rule<Iterator, void(std::string), space_type> end_tag;
};
///////////////////////////////////////////////////////////////////////////////
// A couple of phoenix functions helping to access the elements of the
// generated AST
///////////////////////////////////////////////////////////////////////////////
template <typename T>
struct get_element
{
template <typename T1>
struct result { typedef T const& type; };
T const& operator()(mini_xml_node const& node) const
{
return boost::get<T>(node);
}
};
phoenix::function<get_element<std::string> > _string;
phoenix::function<get_element<mini_xml> > _xml;
///////////////////////////////////////////////////////////////////////////////
// The output grammar defining the format of the generated data
///////////////////////////////////////////////////////////////////////////////
//[mini_xml_karma_sr_grammar
template <typename OutputIterator>
struct mini_xml_generator
: karma::grammar<OutputIterator, mini_xml()>
{
mini_xml_generator() : mini_xml_generator::base_type(xml)
{
node %= ascii::string | xml;
xml =
'<' << ascii::string[qi::_1 = phoenix::at_c<0>(qi::_val)] << '>'
<< (*node)[qi::_1 = phoenix::at_c<1>(qi::_val)]
<< "</" << ascii::string[qi::_1 = phoenix::at_c<0>(qi::_val)] << '>'
;
}
karma::rule<OutputIterator, mini_xml()> xml;
karma::rule<OutputIterator, mini_xml_node()> node;
};
//]
///////////////////////////////////////////////////////////////////////////////
// Main program
///////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv)
{
char const* filename;
if (argc > 1)
{
filename = argv[1];
}
else
{
std::cerr << "Error: No input file provided." << std::endl;
return 1;
}
std::ifstream in(filename, std::ios_base::in);
if (!in)
{
std::cerr << "Error: Could not open input file: "
<< filename << std::endl;
return 1;
}
std::string storage; // We will read the contents here.
in.unsetf(std::ios::skipws); // No white space skipping!
std::copy(
std::istream_iterator<char>(in),
std::istream_iterator<char>(),
std::back_inserter(storage));
typedef mini_xml_parser<std::string::const_iterator> mini_xml_parser;
mini_xml_parser xmlin; // Our grammar definition
mini_xml ast; // our tree
std::string::const_iterator iter = storage.begin();
std::string::const_iterator end = storage.end();
bool r = qi::phrase_parse(iter, end, xmlin, space, ast);
if (r && iter == end)
{
std::cout << "-------------------------n";
std::cout << "Parsing succeededn";
std::cout << "-------------------------n";
typedef std::back_insert_iterator<std::string> outiter_type;
typedef mini_xml_generator<outiter_type> mini_xml_generator;
mini_xml_generator xmlout; // Our grammar definition
std::string generated;
outiter_type outit(generated);
bool r = karma::generate(outit, xmlout, ast);
if (r)
std::cout << generated << std::endl;
return 0;
}
else
{
std::string::const_iterator begin = storage.begin();
std::size_t dist = std::distance(begin, iter);
std::string::const_iterator some =
iter + (std::min)(storage.size()-dist, std::size_t(30));
std::string context(iter, some);
std::cout << "-------------------------n";
std::cout << "Parsing failedn";
std::cout << "stopped at: ": " << context << "..."n";
std::cout << "-------------------------n";
return 1;
}
}
错误消息的开头：
1>------ Build started: Project: test_project, Configuration: Debug Win32 ------
1>Compiling...
1>test_project.cpp
1>c:rtgcodethirdpartythirdpartyboost/spirit/home/phoenix/operator/self.hpp(27) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'const std::list<_Ty>' (or there is no acceptable conversion)
1> with
1> [
1> _Ty=mini_xml_node
1> ]
1> c:Program Files (x86)Microsoft Visual Studio 9.0VCincludevector(562): could be 'std::vector<_Ty> &std::vector<_Ty>::operator =(const std::vector<_Ty> &)'
1> with
1> [
1> _Ty=boost::variant<boost::recursive_wrapper<mini_xml>,std::string>
1> ]
1> while trying to match the argument list '(std::vector<_Ty>, const std::list<_Ty>)'
1> with
1> [
1> _Ty=boost::variant<boost::recursive_wrapper<mini_xml>,std::string>
1> ]
1> and
1> [
1> _Ty=mini_xml_node
1> ]
1> c:rtgcodethirdpartythirdpartyboost/mpl/eval_if.hpp(41) : see reference to class template instantiation 'boost::phoenix::result_of_assign<X,Y>' being compiled
1> with
1> [
1> X=std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> ,
1> Y=const std::list<mini_xml_node>
1> ]
1> c:rtgcodethirdpartythirdpartyboost/spirit/home/phoenix/operator/self.hpp(69) : see reference to class template instantiation 'boost::mpl::eval_if<C,F1,F2>' being compiled
1> with
1> [
1> C=boost::mpl::or_<boost::phoenix::is_actor<std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> >,boost::phoenix::is_actor<const std::list<mini_xml_node> >>,
1> F1=boost::phoenix::re_curry<boost::phoenix::assign_eval,std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> ,const std::list<mini_xml_node> >,
1> F2=boost::phoenix::result_of_assign<std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> ,const std::list<mini_xml_node> >
1> ]
1> c:rtgcodethirdpartythirdpartyboost/spirit/home/phoenix/core/detail/composite_eval.hpp(88) : see reference to class template instantiation 'boost::phoenix::assign_eval::result<Env,A0,A1>' being compiled
1> with
1> [
1> Env=boost::phoenix::basic_environment<boost::fusion::vector1<std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> &>,boost::spirit::context<boost::fusion::cons<const mini_xml &,boost::fusion::nil>,boost::fusion::vector0<>>,bool>,
1> A0=boost::spirit::argument<0>,
1> A1=boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>
1> ]
1> c:rtgcodethirdpartythirdpartyboost/spirit/home/phoenix/core/composite.hpp(60) : see reference to class template instantiation 'boost::phoenix::detail::composite_eval<2>::result<Composite,Env>' being compiled
1> with
1> [
1> Composite=boost::phoenix::composite<boost::phoenix::assign_eval,boost::fusion::vector<boost::spirit::argument<0>,boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,
1> Env=boost::phoenix::basic_environment<boost::fusion::vector1<std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> &>,boost::spirit::context<boost::fusion::cons<const mini_xml &,boost::fusion::nil>,boost::fusion::vector0<>>,bool>
1> ]
1> c:rtgcodethirdpartythirdpartyboost/spirit/home/phoenix/core/actor.hpp(56) : see reference to class template instantiation 'boost::phoenix::composite<EvalPolicy,EvalTuple>::result<Env>' being compiled
1> with
1> [
1> EvalPolicy=boost::phoenix::assign_eval,
1> EvalTuple=boost::fusion::vector<boost::spirit::argument<0>,boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>,
1> Env=boost::phoenix::basic_environment<boost::fusion::vector1<std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> &>,boost::spirit::context<boost::fusion::cons<const mini_xml &,boost::fusion::nil>,boost::fusion::vector0<>>,bool>
1> ]
1> c:rtgcodethirdpartythirdpartyboost/spirit/home/phoenix/core/detail/actor.hpp(48) : see reference to class template instantiation 'boost::phoenix::eval_result<Eval,Env>' being compiled
1> with
1> [
1> Eval=boost::phoenix::composite<boost::phoenix::assign_eval,boost::fusion::vector<boost::spirit::argument<0>,boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,
1> Env=boost::phoenix::basic_environment<boost::fusion::vector1<std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> &>,boost::spirit::context<boost::fusion::cons<const mini_xml &,boost::fusion::nil>,boost::fusion::vector0<>>,bool>
1> ]
1> c:rtgcodethirdpartythirdpartyboost/spirit/home/support/action_dispatch.hpp(178) : see reference to class template instantiation 'boost::phoenix::actor<Eval>::result<Sig>' being compiled
1> with
1> [
1> Eval=boost::phoenix::composite<boost::phoenix::assign_eval,boost::fusion::vector<boost::spirit::argument<0>,boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,
1> Sig=boost::phoenix::actor<boost::phoenix::composite<boost::phoenix::assign_eval,boost::fusion::vector<boost::spirit::argument<0>,boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>> (boost::fusion::vector1<std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>> &> &,boost::spirit::context<boost::fusion::cons<const mini_xml &,boost::fusion::nil>,boost::fusion::vector0<>> &,bool &)
1> ]
1> c:rtgcodethirdpartythirdpartyboost/spirit/home/karma/action/action.hpp(69) : see reference to function template instantiation 'bool boost::spirit::traits::action_dispatch<Component>::operator ()<boost::phoenix::composite<EvalPolicy,EvalTuple>,std::vector<_Ty>,Context>(const boost::phoenix::actor<Eval> &,Attribute &,Context &)' being compiled
1> with
1> [
1> Component=boost::spirit::karma::kleene<boost::spirit::karma::reference<const boost::spirit::karma::rule<outiter_type,mini_xml_node (void)>>>,
1> EvalPolicy=boost::phoenix::assign_eval,
1> EvalTuple=boost::fusion::vector<boost::spirit::argument<0>,boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>,
1> _Ty=boost::variant<boost::recursive_wrapper<mini_xml>,std::string>,
1> Context=boost::spirit::context<boost::fusion::cons<const mini_xml &,boost::fusion::nil>,boost::fusion::vector0<>>,
1> Eval=boost::phoenix::composite<boost::phoenix::assign_eval,boost::fusion::vector<boost::spirit::argument<0>,boost::phoenix::composite<boost::phoenix::at_eval<1>,boost::fusion::vector<boost::spirit::attribute<0>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_,boost::fusion::void_>>,
1> Attribute=std::vector<boost::variant<boost::recursive_wrapper<mini_xml>,std::string>>
1> ]
*snip*
在Visual Studio 2008中使用boost v1.50.0编译。
旁注：如果不先将 karma：：subrule 更改为 karma：：rule，我就无法编译原始示例。1.50.0 中的子规则有问题吗？有没有比我所做的更好的解决方法？
这是
Boost Spirit的另一个案例："语义行为是邪恶的"？
如果您更改为列表，出于显而易见的原因，push_back不起作用。所以，改变
>> *node [push_back(at_c<1>(_val), _1)]
到
>> *node [phoenix::insert(at_c<1>(_val), phoenix::end(at_c<1>(_val)), _1)]
在生成器端，用更简单的语义操作替换所有语义操作的使用，该操作允许您仍然依赖属性兼容性魔术来处理所有其他操作：
karma::_a_type element_name_; // using karma::locals<std::string>
xml %=
'<' << string[element_name_ = _1] << '>'
<< *node
<< "</" << string(element_name_) << '>'
;
<咆哮>所有这些都只是更多的证据，证明代码越少越好。干扰少，拼出来少，依赖内置机制。一旦你干涉(通过为属性提取编写精确的、命令式的、语义的操作(，当你想要维护代码时，你就输了.
更新 现在删除了所有无端使用语义操作，因此我们有一个 Qi 语法和 Karma 生成器，无需任何额外工作即可与list和vector一起使用。还修复了一些风格的元素(不再using namespace(。
这意味着不再需要上述phoenix::insert(at_c<1>(_val), phoenix::end(at_c<1>(_val)), _1)：
qi::_a_type element_name_;
xml %=
start_tag[element_name_ = _1]
>> *node
>> end_tag(element_name_)
;
住在科里鲁
#define BOOST_SPIRIT_USE_PHOENIX_V3
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/karma.hpp>
#include <boost/spirit/include/phoenix.hpp>
#include <boost/spirit/include/phoenix_function.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <boost/variant/recursive_variant.hpp>
#include <iostream>
#include <fstream>
#include <string>
#include <list>
namespace fusion = boost::fusion;
namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
namespace karma = boost::spirit::karma;
namespace phoenix = boost::phoenix;
///////////////////////////////////////////////////////////////////////////////
// Our mini XML tree representation
///////////////////////////////////////////////////////////////////////////////
struct mini_xml;
typedef
boost::variant<
boost::recursive_wrapper<mini_xml>
, std::string
>
mini_xml_node;
typedef std::list<mini_xml_node> mini_xml_nodes;
struct mini_xml
{
std::string name; // tag name
mini_xml_nodes children; // children
};
// We need to tell fusion about our mini_xml struct
// to make it a first-class fusion citizen
BOOST_FUSION_ADAPT_STRUCT(
mini_xml,
(std::string, name)
(mini_xml_nodes, children)
)
///////////////////////////////////////////////////////////////////////////////
// Our mini XML grammar definition
///////////////////////////////////////////////////////////////////////////////
template <typename Iterator>
struct mini_xml_parser :
qi::grammar<Iterator, mini_xml(), qi::space_type>
{
mini_xml_parser() : mini_xml_parser::base_type(start)
{
using qi::lit;
using qi::lexeme;
using ascii::char_;
using ascii::string;
using namespace qi::labels;
text %= lexeme[+(char_ - '<')];
node %= xml | text;
start_tag %=
'<'
>> !lit('/')
>> lexeme[+(char_ - '>')]
>> '>'
;
end_tag =
"</"
>> string(_r1)
>> '>'
;
qi::_a_type element_name_;
xml %=
start_tag[element_name_ = _1]
>> *node
>> end_tag(element_name_)
;
start = xml;
}
qi::rule<Iterator, mini_xml(), qi::space_type> start;
qi::rule<Iterator, mini_xml(), qi::space_type, qi::locals<std::string> > xml;
qi::rule<Iterator, mini_xml_node(), qi::space_type> node;
qi::rule<Iterator, std::string(), qi::space_type> text;
qi::rule<Iterator, std::string(), qi::space_type> start_tag;
qi::rule<Iterator, void(std::string), qi::space_type> end_tag;
};
///////////////////////////////////////////////////////////////////////////////
// A couple of phoenix functions helping to access the elements of the
// generated AST
///////////////////////////////////////////////////////////////////////////////
template <typename T>
struct get_element
{
template <typename T1>
struct result { typedef T const& type; };
T const& operator()(mini_xml_node const& node) const
{
return boost::get<T>(node);
}
};
phoenix::function<get_element<std::string> > _string;
phoenix::function<get_element<mini_xml> > _xml;
///////////////////////////////////////////////////////////////////////////////
// The output grammar defining the format of the generated data
///////////////////////////////////////////////////////////////////////////////
//[mini_xml_karma_sr_grammar
template <typename OutputIterator>
struct mini_xml_generator
: karma::grammar<OutputIterator, mini_xml()>
{
mini_xml_generator() : mini_xml_generator::base_type(entry)
{
karma::_a_type element_name_;
xml %=
'<' << karma::string[element_name_ = karma::_1] << '>'
<< *node
<< "</" << karma::string(element_name_) << '>'
;
node %= karma::string | xml;
entry %= node;
}
karma::rule<OutputIterator, mini_xml()> entry;
karma::rule<OutputIterator, mini_xml(), qi::locals<std::string> > xml;
karma::rule<OutputIterator, mini_xml_node()> node;
};
//]
///////////////////////////////////////////////////////////////////////////////
// Main program
///////////////////////////////////////////////////////////////////////////////
int main(int argc, char **argv)
{
char const* filename;
if (argc > 1)
{
filename = argv[1];
}
else
{
std::cerr << "Error: No input file provided." << std::endl;
return 1;
}
std::ifstream in(filename, std::ios_base::in);
if (!in)
{
std::cerr << "Error: Could not open input file: "
<< filename << std::endl;
return 1;
}
std::string storage; // We will read the contents here.
in.unsetf(std::ios::skipws); // No white space skipping!
std::copy(
std::istream_iterator<char>(in),
std::istream_iterator<char>(),
std::back_inserter(storage));
typedef mini_xml_parser<std::string::const_iterator> mini_xml_parser;
mini_xml_parser xmlin; // Our grammar definition
mini_xml ast; // our tree
std::string::const_iterator iter = storage.begin();
std::string::const_iterator end = storage.end();
bool r = qi::phrase_parse(iter, end, xmlin, qi::space, ast);
if (r && iter == end)
{
std::cout << "-------------------------n";
std::cout << "Parsing succeededn";
std::cout << "-------------------------n";
typedef std::back_insert_iterator<std::string> outiter_type;
typedef mini_xml_generator<outiter_type> mini_xml_generator;
mini_xml_generator xmlout; // Our grammar definition
std::string generated;
outiter_type outit(generated);
bool r = karma::generate(outit, xmlout, ast);
if (r)
std::cout << generated << std::endl;
return 0;
}
else
{
std::string::const_iterator begin = storage.begin();
std::size_t dist = std::distance(begin, iter);
std::string::const_iterator some =
iter + (std::min)(storage.size()-dist, std::size_t(30));
std::string context(iter, some);
std::cout << "-------------------------n";
std::cout << "Parsing failedn";
std::cout << "stopped at: ": " << context << "..."n";
std::cout << "-------------------------n";
return 1;
}
}
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