Dear Boost Spirit experts,
I've been using Spirit for a few weeks and it is one of the most
impressive things I've seen for a long time. Thanks to everyone who has
made this possible.
Its main problem, as far as I can see, is that the error messages are
almost entirely incomprehensible. This is not unusual for C++; the
compiler (gcc in my case) has a share of the blame too. The result, in
my case, is not venturing much beyond the structures used in the
examples from the (excellent) documentation, and debugging by trial and
error.
Anyway, I am trying to write a parser that will:
- Use a file_iterator to parse a file.
- Skip comments using #-to-end-of-line syntax.
- Skip whitespace.
- Recognise a simple language.
I can do the main part of the parser (the language); the problem is with
the comment skipper. I think that using file_iterator might be making
it more complicated, though I have also failed to get a char* version to
compile.
Following the suggestions at
http://spirit.sourceforge.net/distrib/spirit_1_8_2/libs/spirit/doc/file_iter...
I have written the following test program:
#include <string>
#include
#include
#include
using namespace std;
using namespace boost::spirit;
int main(int argc, char* argv[])
{
string fn = argv[1];
typedef file_iterator<char> iterator_t;
typedef scanner scanner_t;
typedef rule rule_t;
rule_t skip = comment_p("#") | space_p ;
rule_t language = * ch_p('X') ;
iterator_t first(fn.c_str());
if (!first) {
cout << "Unable to open " << fn << endl;
exit(1);
}
iterator_t last = first.make_end();
parse_info info = parse(first, last, language, skip);
}
The errors are attached below. Can anyone spot what I need to change?
My feeling is that I need a different type for skip, i.e. not rule_t,
and I'm pretty sure that I need a definition for scanner_t that mentions
skip. I've tried various combinations and got different, equally
verbose and incomprehensible, error messages.
I'm using Boost 1.32.0 with gcc 3.3.6 on Debian Linux.
Many thanks in advance for any suggestions.
Phil.
$ g++ -Wall -O -o spirit_test spirit_test.cc
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp: In member
function `
typename boost::spirit::parser_result::type
boost::spirit::impl::rule_base::parse_main(const ScannerT&) const [with ScannerT =
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy>, boost::spirit::match_policy,
boost::spirit::action_policy> >, DerivedT =
boost::spirit::rule,
EmbedT =
const boost::spirit::rule&, T0 = main(int,
char**)::scanner_t, T1 = boost::spirit::nil_t, T2 =
boost::spirit::nil_t]':
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:171:
instantiated from `typename boost::spirit::parser_result::type boost::spirit::impl::rule_base::parse(const ScannerT&) const [with ScannerT =
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy>, boost::spirit::match_policy,
boost::spirit::action_policy> >, DerivedT =
boost::spirit::rule, EmbedT = const boost::spirit::rule&, T0 =
main(int, char**)::scanner_t, T1 = boost::spirit::nil_t, T2 =
boost::spirit::nil_t]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:107:
instantiated from `static boost::spirit::parse_info<IteratorT>
boost::spirit::impl::phrase_parser<SkipT>::parse(const IteratorT&, const
IteratorT&, const ParserT&, const SkipT&) [with IteratorT =
boost::spirit::file_iterator, ParserT =
boost::spirit::rule, SkipT = boost::spirit::rule]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:154:
instantiated from `boost::spirit::parse_info<IteratorT>
boost::spirit::parse(const IteratorT&, const IteratorT&, const
boost::spirit::parser<DerivedT>&, const boost::spirit::parser<SkipT>&)
[with IteratorT = main(int, char**)::iterator_t, ParserT =
boost::spirit::rule, SkipT = boost::spirit::rule]'
spirit_test.cc:29: instantiated from here
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:189: error: no
matching function for call to `
boost::spirit::impl::abstract_parser::do_parse_virtual(const
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy>, boost::spirit::match_policy,
boost::spirit::action_policy> >&)'
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:213: error:
candidates are: typename boost::spirit::match_result::type
boost::spirit::impl::abstract_parser::do_parse_virtual(const ScannerT&) const [with ScannerT =
main(int,
char**)::scanner_t, AttrT = boost::spirit::nil_t]
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp: In member
function `
typename boost::spirit::parser_result::type
boost::spirit::impl::rule_base::parse_main(const ScannerT&) const [with ScannerT =
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy> >, boost::spirit::match_policy,
boost::spirit::action_policy> >, DerivedT =
boost::spirit::rule,
EmbedT =
const boost::spirit::rule&, T0 = main(int,
char**)::scanner_t, T1 = boost::spirit::nil_t, T2 =
boost::spirit::nil_t]':
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:171:
instantiated from `typename boost::spirit::parser_result::type boost::spirit::impl::rule_base::parse(const ScannerT&) const [with ScannerT =
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy> >, boost::spirit::match_policy,
boost::spirit::action_policy> >, DerivedT =
boost::spirit::rule, EmbedT = const boost::spirit::rule&, T0 =
main(int, char**)::scanner_t, T1 = boost::spirit::nil_t, T2 =
boost::spirit::nil_t]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:42:
instantiated from `void boost::spirit::impl::skipper_skip(const ST&,
const ScannerT&, const boost::spirit::skipper_iteration_policy<BaseT>&)
[with ST = boost::spirit::rule, ScannerT =
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy>, boost::spirit::match_policy,
boost::spirit::action_policy> >, BaseT = boost::spirit::iteration_policy]'
/usr/include/boost/spirit/core/scanner/skipper.hpp:114: instantiated
from `void boost::spirit::skip_parser_iteration_policy::skip(const ScannerT&) const [with ScannerT =
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy>, boost::spirit::match_policy,
boost::spirit::action_policy> >, ParserT = boost::spirit::rule, BaseT =
boost::spirit::iteration_policy]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:108:
instantiated from `static boost::spirit::parse_info<IteratorT>
boost::spirit::impl::phrase_parser<SkipT>::parse(const IteratorT&, const
IteratorT&, const ParserT&, const SkipT&) [with IteratorT =
boost::spirit::file_iterator, ParserT =
boost::spirit::rule, SkipT = boost::spirit::rule]'
/usr/include/boost/spirit/core/scanner/impl/skipper.ipp:154:
instantiated from `boost::spirit::parse_info<IteratorT>
boost::spirit::parse(const IteratorT&, const IteratorT&, const
boost::spirit::parser<DerivedT>&, const boost::spirit::parser<SkipT>&)
[with IteratorT = main(int, char**)::iterator_t, ParserT =
boost::spirit::rule, SkipT = boost::spirit::rule]'
spirit_test.cc:29: instantiated from here
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:189: error: no
matching function for call to `
boost::spirit::impl::abstract_parser::do_parse_virtual(const
boost::spirit::scanner,
boost::spirit::scanner_policies,
boost::spirit::iteration_policy> >, boost::spirit::match_policy,
boost::spirit::action_policy> >&)'
/usr/include/boost/spirit/core/non_terminal/impl/rule.ipp:213: error:
candidates are: typename boost::spirit::match_result::type
boost::spirit::impl::abstract_parser::do_parse_virtual(const ScannerT&) const [with ScannerT =
main(int,
char**)::scanner_t, AttrT = boost::spirit::nil_t]
