编辑：我已经删除了词法分析器，因为它没有与 Qi 完全集成，只是混淆了语法（见这里）。
完整的语法和词法分析器在最后。首先介绍我遇到问题的语法和输入。
这很好用：
/*input*/ " EVENT 1:ev1 { OPTIONAL 1:hassan int4; } ";
event_descriptor_ = tok.event
>> oid_
>> tok.left_curly >> event_entry_ >> tok.right_curly;
这失败了：
/*input*/ " EVENT 1:ev1 { OPTIONAL 1:hassan int4; OPTION 2:hassan2 int8; }";
event_descriptor_ = tok.event
>> oid_
>> tok.left_curly >> *(event_entry_) >> tok.right_curly;
和 ：
Assertion failed: (std::size_t(~0) != token_state_), function parse, file /usr/local/include/boost/spirit/home/lex/lexer/token_def.hpp, line 100.
Abort trap: 6
指向源代码注释：
// If the following assertion fires you probably forgot to
// associate this token definition with a lexer instance.
BOOST_ASSERT(std::size_t(~0) != token_state_);
从语法和输入中删除最后一个卷曲也可以：
/*input*/ " EVENT 1:ev1 { OPTIONAL 1:hassan int4; OPTION 2:hassan2 int8; ";
event_descriptor_ = tok.event
>> oid_
>> tok.left_curly >> *(event_entry_);
完整文件：
#include <boost/spirit/include/phoenix_core.hpp>
#include <boost/spirit/home/phoenix/bind/bind_member_variable.hpp>
#include <boost/spirit/include/lex_lexertl.hpp>
#include <boost/spirit/include/qi.hpp>
#include <boost/none.hpp>
#include <boost/cstdint.hpp>
#include <boost/fusion/include/adapt_struct.hpp>
#include <string>
#include <exception>
#include <vector>
namespace lex = boost::spirit::lex;
namespace px = boost::phoenix;
namespace qi = boost::spirit::qi;
namespace ascii = boost::spirit::ascii;
template <typename Lexer>
struct tokens : lex::lexer<Lexer>
{
tokens()
: left_curly("\"{\""),
right_curly("\"}\""),
left_paren("\"(\""),
right_paren("\")\""),
colon(":"),
scolon(";"),
namespace_("(?i:namespace)"),
event("(?i:event)"),
optional("(?i:optional)"),
required("(?i:required)"),
repeated("(?i:repeated)"),
t_int_4("(?i:int4)"),
t_int_8("(?i:int8)"),
t_string("(?i:string)"),
ordinal("\\d+"),
identifier("\\w+")
{
using boost::spirit::lex::_val;
this->self
=
left_curly [ std::cout << px::val("lpar") << std::endl]
| right_curly [ std::cout << px::val("rpar") << std::endl]
| left_paren
| right_paren
| colon [ std::cout << px::val("colon") << std::endl]
| scolon
| namespace_ [ std::cout << px::val("kw namesapce") << std::endl]
| event [ std::cout << px::val("kw event") << std::endl]
| optional [ std::cout << px::val("optional ") << "-->" << _val << "<--" << std::endl]
| required [ std::cout << px::val("required") << std::endl]
| t_int_4
| t_int_8
| t_string
| ordinal [ std::cout << px::val("val ordinal (") << _val << ")" << std::endl]
| identifier [std::cout << px::val("val identifier(") << _val << ")" << std::endl];
this->self("WS") = lex::token_def<>("[ \\t\\n]+");
}
lex::token_def<lex::omit> left_curly, right_curly, colon, scolon,repeated, left_paren, right_paren;
lex::token_def<lex::omit> namespace_, event, optional, required,t_int_4, t_int_8, t_string;
lex::token_def<boost::uint32_t> ordinal;
lex::token_def<> identifier;
};
enum event_entry_qualifier
{
ENTRY_OPTIONAL,
ENTRY_REQUIRED,
ENTRY_REPEATED
};
enum entry_type
{
RBL_INT4,
RBL_INT8,
RBL_STRING,
RBL_EVENT
};
struct oid
{
boost::uint32_t ordinal;
std::string name;
};
BOOST_FUSION_ADAPT_STRUCT
(
oid,
(boost::uint32_t, ordinal)
(std::string, name)
)
struct type_descriptor
{
entry_type type_id;
std::string referenced_event;
};
BOOST_FUSION_ADAPT_STRUCT
(
type_descriptor,
(entry_type, type_id)
(std::string, referenced_event)
)
struct event_entry
{
event_entry_qualifier qualifier;
oid identifier;
type_descriptor descriptor;
};
BOOST_FUSION_ADAPT_STRUCT
(
event_entry,
(event_entry_qualifier, qualifier)
(oid, identifier)
(type_descriptor, descriptor)
)
struct event_descriptor
{
oid identifier;
std::vector<event_entry> event_entries;
};
BOOST_FUSION_ADAPT_STRUCT
(
event_descriptor,
(oid, identifier)
(std::vector<event_entry>, event_entries)
)
template <typename Iterator, typename Lexer>
struct grammar : qi::grammar<Iterator,event_descriptor(), qi::in_state_skipper<Lexer> >
{
template <typename TokenDef>
grammar(TokenDef const& tok)
: grammar::base_type(event_descriptor_)
{
using qi::_val;
//start = event;
event_descriptor_ = tok.event >> oid_ >> tok.left_curly >> *(event_entry_);
event_entry_ = event_qualifier >> oid_ >> type_descriptor_ >> tok.scolon;
event_qualifier = tok.optional [ _val = ENTRY_OPTIONAL]
| tok.required [ _val = ENTRY_REQUIRED]
| tok.repeated [ _val = ENTRY_REPEATED];
oid_ = tok.ordinal
>> tok.colon
>> tok.identifier;
type_descriptor_
= (( atomic_type >> qi::attr(""))
| ( event_type >> tok.left_paren >> tok.identifier >> tok.right_paren));
atomic_type = tok.t_int_4 [ _val = RBL_INT4]
| tok.t_int_8 [ _val = RBL_INT8]
| tok.t_string [ _val = RBL_STRING];
event_type = tok.event [_val = RBL_EVENT];
}
qi::rule<Iterator> start;
qi::rule<Iterator, event_descriptor(), qi::in_state_skipper<Lexer> > event_descriptor_;
qi::rule<Iterator, event_entry(), qi::in_state_skipper<Lexer> > event_entry_;
qi::rule<Iterator, event_entry_qualifier()> event_qualifier;
qi::rule<Iterator, entry_type()> atomic_type;
qi::rule<Iterator, entry_type()> event_type;
qi::rule<Iterator, type_descriptor(),qi::in_state_skipper<Lexer> > type_descriptor_;
qi::rule<Iterator, oid()> oid_;
};
std::string test = " EVENT 1:sihan { OPTIONAL 123:hassan int4; OPTIONAL 123:hassan int4; ";
int main()
{
typedef lex::lexertl::token<std::string::iterator, boost::mpl::vector<boost::uint32_t, std::string> > token_type;
typedef lex::lexertl::actor_lexer<token_type> lexer_type;
typedef tokens<lexer_type>::iterator_type iterator_type;
tokens<lexer_type> token_lexer;
grammar<iterator_type,tokens<lexer_type>::lexer_def> grammar(token_lexer);
std::string::iterator it = test.begin();
iterator_type first = token_lexer.begin(it, test.end());
iterator_type last = token_lexer.end();
bool r;
r = qi::phrase_parse(first, last, grammar, qi::in_state("WS")[token_lexer.self]);
if(r)
;
else
{
std::cout << "parsing failed" << std::endl;
}
/*
lexer_type::iterator_type iter;
try
{
iter = token_lexer.begin(first,last);
}
catch(std::exception & e)
{
std::cout << e.what() << std::endl;
}
lexer_type::iterator_type end = token_lexer.end();
while (iter != end && token_is_valid(*iter))
++iter;
*/
}