Boost::spirit (classic) primitives vs custom parsers - c++

Question

I'm a beginner in Boost::spirit and I want to define grammar that parses TTCN language.
(http://www.trex.informatik.uni-goettingen.de/trac/wiki/ttcn-3_4.5.1)
I'm trying to define some rules for 'primitve' parsers like Alpha, AlphaNum to be faitful 1 to 1 to original grammar but obviously I do something wrong because grammar defined this way does not work.
But when I use primite parsers in place of TTCN's it started to work.
Can someone tell why 'manually' defined rules does not work as expected ?
How to fix it, because I would like to stick close to original grammar.
Is it a begginer's code bug or something different ?
#define BOOST_SPIRIT_DEBUG
#include <boost/spirit/include/classic_symbols.hpp>
#include <boost/spirit/include/classic_tree_to_xml.hpp>
#include <boost/spirit/include/classic_position_iterator.hpp>
#include <boost/spirit/include/classic_core.hpp>
#include <boost/spirit/include/classic_parse_tree.hpp>
#include <boost/spirit/include/classic_ast.hpp>
#include <iostream>
#include <string>
#include <boost/spirit/home/classic/debug.hpp>
using namespace boost::spirit::classic;
using namespace std;
using namespace BOOST_SPIRIT_CLASSIC_NS;
typedef node_iter_data_factory<int> factory_t;
typedef position_iterator<std::string::iterator> pos_iterator_t;
typedef tree_match<pos_iterator_t, factory_t> parse_tree_match_t;
typedef parse_tree_match_t::const_tree_iterator iter_t;
struct ParseGrammar: public grammar<ParseGrammar>
{
template<typename ScannerT>
struct definition
{
definition(ParseGrammar const &)
{
KeywordImport = str_p("import");
KeywordAll = str_p("all");
SemiColon = ch_p(';');
Underscore = ch_p('_');
NonZeroNum = range_p('1','9');
Num = ch_p('0') | NonZeroNum;
UpperAlpha = range_p('A', 'Z');
LowerAlpha = range_p('a', 'z');
Alpha = UpperAlpha | LowerAlpha;
AlphaNum = Alpha | Num;
//this does not!
Identifier = lexeme_d[Alpha >> *(AlphaNum | Underscore)];
// Uncomment below line to make rule work
// Identifier = lexeme_d[alpha_p >> *(alnum_p | Underscore)];
Module = KeywordImport >> Identifier >> KeywordAll >> SemiColon;
BOOST_SPIRIT_DEBUG_NODE(Module);
BOOST_SPIRIT_DEBUG_NODE(KeywordImport);
BOOST_SPIRIT_DEBUG_NODE(KeywordAll);
BOOST_SPIRIT_DEBUG_NODE(Identifier);
BOOST_SPIRIT_DEBUG_NODE(SemiColon);
}
rule<ScannerT> KeywordImport,KeywordAll,Module,Identifier,SemiColon;
rule<ScannerT> Alpha,UpperAlpha,LowerAlpha,Underscore,Num,AlphaNum;
rule<ScannerT> NonZeroNum;
rule<ScannerT> const&
start() const { return Module; }
};
};
int main()
{
ParseGrammar resolver; // Our parser
BOOST_SPIRIT_DEBUG_NODE(resolver);
string content = "import foobar all;";
pos_iterator_t pos_begin(content.begin(), content.end());
pos_iterator_t pos_end;
tree_parse_info<pos_iterator_t, factory_t> info;
info = ast_parse<factory_t>(pos_begin, pos_end, resolver, space_p);
std::cout << "\ninfo.length : " << info.length << std::endl;
std::cout << "info.full : " << info.full << std::endl;
if(info.full)
{
std::cout << "OK: Parsing succeeded\n\n";
}
else
{
int line = info.stop.get_position().line;
int column = info.stop.get_position().column;
std::cout << "-------------------------\n";
std::cout << "ERROR: Parsing failed\n";
std::cout << "stopped at: " << line << ":" << column << "\n";
std::cout << "-------------------------\n";
}
return 0;
}

Answer 1

I don't do Spirit Classic (which has been deprecated for some years now).
I can only assume you've mixed something up with skippers. Here's the thing translated into Spirit V2:
#define BOOST_SPIRIT_DEBUG
#include <boost/spirit/include/qi.hpp>
#include <boost/spirit/include/support_line_pos_iterator.hpp>
namespace qi = boost::spirit::qi;
typedef boost::spirit::line_pos_iterator<std::string::const_iterator> pos_iterator_t;
template <typename Iterator = pos_iterator_t, typename Skipper = qi::space_type>
struct ParseGrammar: public qi::grammar<Iterator, Skipper>
{
ParseGrammar() : ParseGrammar::base_type(Module)
{
using namespace qi;
KeywordImport = lit("import");
KeywordAll = lit("all");
SemiColon = lit(';');
#if 1
// this rule obviously works
Identifier = lexeme [alpha >> *(alnum | '_')];
#else
// this does too, but less efficiently
Underscore = lit('_');
NonZeroNum = char_('1','9');
Num = char_('0') | NonZeroNum;
UpperAlpha = char_('A', 'Z');
LowerAlpha = char_('a', 'z');
Alpha = UpperAlpha | LowerAlpha;
AlphaNum = Alpha | Num;
Identifier = lexeme [Alpha >> *(AlphaNum | Underscore)];
#endif
Module = KeywordImport >> Identifier >> KeywordAll >> SemiColon;
BOOST_SPIRIT_DEBUG_NODES((Module)(KeywordImport)(KeywordAll)(Identifier)(SemiColon))
}
qi::rule<Iterator, Skipper> Module;
qi::rule<Iterator> KeywordImport,KeywordAll,Identifier,SemiColon;
qi::rule<Iterator> Alpha,UpperAlpha,LowerAlpha,Underscore,Num,AlphaNum;
qi::rule<Iterator> NonZeroNum;
};
int main()
{
std::string const content = "import \r\n\r\nfoobar\r\n\r\n all; bogus";
pos_iterator_t first(content.begin()), iter=first, last(content.end());
ParseGrammar<pos_iterator_t> resolver; // Our parser
bool ok = phrase_parse(iter, last, resolver, qi::space);
std::cout << std::boolalpha;
std::cout << "\nok : " << ok << std::endl;
std::cout << "full : " << (iter == last) << std::endl;
if(ok && iter==last)
{
std::cout << "OK: Parsing fully succeeded\n\n";
}
else
{
int line = get_line(iter);
int column = get_column(first, iter);
std::cout << "-------------------------\n";
std::cout << "ERROR: Parsing failed or not complete\n";
std::cout << "stopped at: " << line << ":" << column << "\n";
std::cout << "remaining: '" << std::string(iter, last) << "'\n";
std::cout << "-------------------------\n";
}
return 0;
}
I've added a little "bogus" at the end of input, so the output becomes a nicer demonstration:
<Module>
<try>import \r\n\r\nfoobar\r\n\r</try>
<KeywordImport>
<try>import \r\n\r\nfoobar\r\n\r</try>
<success> \r\n\r\nfoobar\r\n\r\n all;</success>
<attributes>[]</attributes>
</KeywordImport>
<Identifier>
<try>foobar\r\n\r\n all; bogu</try>
<success>\r\n\r\n all; bogus</success>
<attributes>[]</attributes>
</Identifier>
<KeywordAll>
<try>all; bogus</try>
<success>; bogus</success>
<attributes>[]</attributes>
</KeywordAll>
<SemiColon>
<try>; bogus</try>
<success> bogus</success>
<attributes>[]</attributes>
</SemiColon>
<success> bogus</success>
<attributes>[]</attributes>
</Module>
ok : true
full : false
-------------------------
ERROR: Parsing failed or not complete
stopped at: 3:8
remaining: 'bogus'
-------------------------
That all said, this is what I'd probably reduce it to:
template <typename Iterator, typename Skipper = qi::space_type>
struct ParseGrammar: public qi::grammar<Iterator, Skipper>
{
ParseGrammar() : ParseGrammar::base_type(Module)
{
using namespace qi;
Identifier = alpha >> *(alnum | '_');
Module = "import" >> Identifier >> "all" >> ';';
BOOST_SPIRIT_DEBUG_NODES((Module)(Identifier))
}
qi::rule<Iterator, Skipper> Module;
qi::rule<Iterator> Identifier;
};
As you can see, the Identifier rule is implicitely a lexeme because it doesn't declared to use a skipper.
See it Live on Coliru