Reputation: 13
Writing Qi grammar with Phoenix bind I got a compilation error like
boost/spirit/home/support/context.hpp(180): error C2338: index_is_out_of_bounds
here
>> ruleHandId_[phx::bind(&parseContext::handId_, qi::_r1) = qi::_1];
I just havent too much expirience with phoenix binding but perv bind in the line
ruleStart_ = ruleEncoding_[phx::bind(&parseContext::encoding_, qi::_r1) = qi::_1]
works good without compilation errors
It's all under MSVC from VS2013 with boost 1.56 x86
Whats I do wrong under code with the compilation error?
Source Code
#include <boost/spirit/include/qi.hpp>
#include <boost/phoenix/phoenix.hpp>
#include <boost/shared_ptr.hpp>
#include <sstream>
namespace sp = boost::spirit;
namespace qi = boost::spirit::qi;
namespace phx = boost::phoenix;
struct parseContext {
std::string encoding_;
uint64_t handId_;
};
typedef boost::shared_ptr<parseContext> parseContextShPtr;
template <typename Iterator>
struct parseGrammar : qi::grammar<Iterator, void(parseContext&)> {
parseGrammar() : parseGrammar::base_type(ruleStart_)
{
ruleStart_ = ruleEncoding_[phx::bind(&parseContext::encoding_, qi::_r1) = qi::_1]
>> ruleHandHeader_;
ruleEncoding_ = qi::lit("ABC");
ruleHandHeader_ = qi::lit("DEF") >> qi::space
>> qi::lit("XYZ #")
>> ruleHandId_[phx::bind(&parseContext::handId_, qi::_r1) = qi::_1];
ruleHandId_ = qi::long_long;
}
// Rules
qi::rule<Iterator, void(parseContext&)> ruleStart_;
qi::rule<Iterator, std::string()> ruleEncoding_;
qi::rule<Iterator> ruleHandHeader_;
qi::rule<Iterator, uint64_t> ruleHandId_;
};
void test()
{
std::string s("ABCDEF XYZ #555: PQI #777");
std::stringstream sb;
sb.unsetf(std::ios::skipws);
sb << s;
const parseGrammar<sp::istream_iterator> p;
sp::istream_iterator b(sb);
sp::istream_iterator e;
parseContextShPtr ctx(new parseContext);
bool r = qi::parse(b, e, p(phx::ref(*ctx.get())));
if (r) {
std::cout << "Success" << std::endl;
}
else {
std::cout << "Failure" << std::endl;
}
std::cout << std::string(b, e).substr(0, 32) << std::endl;
}
Upvotes: 1
Views: 502
Reputation: 393114
Some of the placeholders cannot be bound.
This could be because ruleEncoding_
doesn't expose an attribute (for _1
) (unlikely) or ruleStart_
doesn't have the inherited attribute (_r1
).
That's all I can tell you right now.
Edit It was the latter. ruleHandHeader
doesn't declare any attributes, let alone an inherited attribute to bind to _r1
Update To the comment.
Here are some suggestions. Much in the vein of my oft-repeated advice to avoid semantic actions (Boost Spirit: "Semantic actions are evil"?), I'd adapt the structure as a fusion sequence:
And use much simplified grammar rules:
ruleStart_ = ruleEncoding_ >> ruleHandHeader_;
ruleEncoding_ = "ABC";
ruleHandId_ = qi::long_long;
ruleHandHeader_ = "DEF XYZ #" >> ruleHandId_;
Now, adding in BOOST_SPIRIT_DEBUG
macros and fixing uint64_t
to uint64_t()
in the rule definition:
#define BOOST_SPIRIT_DEBUG
#include <boost/spirit/include/qi.hpp>
#include <boost/fusion/adapted/struct.hpp>
#include <boost/shared_ptr.hpp>
#include <sstream>
namespace qi = boost::spirit::qi;
struct parseContext {
std::string encoding_;
uint64_t handId_;
};
BOOST_FUSION_ADAPT_STRUCT(parseContext, (std::string, encoding_)(uint64_t,handId_))
typedef boost::shared_ptr<parseContext> parseContextShPtr;
template <typename Iterator>
struct parseGrammar : qi::grammar<Iterator, parseContext()> {
parseGrammar() : parseGrammar::base_type(ruleStart_)
{
ruleStart_ = ruleEncoding_ >> ruleHandHeader_;
ruleEncoding_ = "ABC";
ruleHandId_ = qi::long_long;
ruleHandHeader_ = "DEF XYZ #" >> ruleHandId_;
BOOST_SPIRIT_DEBUG_NODES((ruleStart_)(ruleEncoding_)(ruleHandId_)(ruleHandHeader_))
}
// Rules
qi::rule<Iterator, parseContext()> ruleStart_;
qi::rule<Iterator, std::string()> ruleEncoding_;
qi::rule<Iterator, uint64_t()> ruleHandId_, ruleHandHeader_;
};
void test()
{
std::stringstream sb("ABCDEF XYZ #555: PQI #777");
sb.unsetf(std::ios::skipws);
typedef boost::spirit::istream_iterator It;
const parseGrammar<It> p;
It b(sb), e;
parseContextShPtr ctx(new parseContext);
bool r = qi::parse(b, e, p, *ctx);
if (r) {
std::cout << "Success: " << ctx->encoding_ << ", " << ctx->handId_ << std::endl;
}
else {
std::cout << "Failure" << std::endl;
}
if (b!=e)
std::cout << "Remaining: '" << std::string(b, e).substr(0, 32) << "'...\n";
}
int main()
{
test();
}
Prints
Success: ABC, 555
Remaining: ': PQI #777'...
Upvotes: 0