/*=============================================================================
    Spirit v1.6.0
    Copyright (c) 1998-2003 Joel de Guzman
    http://spirit.sourceforge.net/

    Permission to copy, use, modify, sell and distribute this software is
    granted provided this copyright notice appears in all copies. This
    software is provided "as is" without express or implied warranty, and
    with no claim as to its suitability for any purpose.
============================================================================*/
#if !defined(BOOST_SPIRIT_SKIPPER_IPP)
#define BOOST_SPIRIT_SKIPPER_IPP

///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit {

    struct space_parser;
    template <typename BaseT>
    struct no_skipper_iteration_policy;

    namespace impl
    {
        template <typename ST, typename ScannerT, typename BaseT>
        inline void
        skipper_skip(
            ST const& s,
            ScannerT const& scan,
            skipper_iteration_policy<BaseT> const&)
        {
            typedef scanner_policies<
                no_skipper_iteration_policy<
                    BOOST_SPIRIT_TYPENAME ScannerT::iteration_policy_t>,
                BOOST_SPIRIT_TYPENAME ScannerT::match_policy_t,
                BOOST_SPIRIT_TYPENAME ScannerT::action_policy_t
            > policies_t;

            scanner<BOOST_SPIRIT_TYPENAME ScannerT::iterator_t, policies_t>
                scan2(scan.first, scan.last, policies_t(scan));
            typedef typename ScannerT::iterator_t iterator_t;

            for (;;)
            {
                iterator_t save = scan.first;
                if (!s.parse(scan2))
                {
                    scan.first = save;
                    break;
                }
            }
        }

        template <typename ST, typename ScannerT, typename BaseT>
        inline void
        skipper_skip(
            ST const& s,
            ScannerT const& scan,
            no_skipper_iteration_policy<BaseT> const&)
        {
            for (;;)
            {
                typedef typename ScannerT::iterator_t iterator_t;
                iterator_t save = scan.first;
                if (!s.parse(scan))
                {
                    scan.first = save;
                    break;
                }
            }
        }

        template <typename ST, typename ScannerT>
        inline void
        skipper_skip(
            ST const& s,
            ScannerT const& scan,
            iteration_policy const&)
        {
            for (;;)
            {
                typedef typename ScannerT::iterator_t iterator_t;
                iterator_t save = scan.first;
                if (!s.parse(scan))
                {
                    scan.first = save;
                    break;
                }
            }
        }

        template <typename SkipT>
        struct phrase_parser
        {
            template <typename IteratorT, typename ParserT>
            static parse_info<IteratorT>
            parse(
                IteratorT const&    first_,
                IteratorT const&    last,
                ParserT const&      p,
                SkipT const&        skip)
            {
                typedef skip_parser_iteration_policy<SkipT> iter_policy_t;
                typedef scanner_policies<iter_policy_t> scanner_policies_t;
                typedef scanner<IteratorT, scanner_policies_t> scanner_t;

                iter_policy_t iter_policy(skip);
                scanner_policies_t policies(iter_policy);
                IteratorT first = first_;
                scanner_t scan(first, last, policies);
                match<nil_t> hit = p.parse(scan);
                return parse_info<IteratorT>(
                    first, hit, hit && (first == last), hit.length());
            }
        };

        template <>
        struct phrase_parser<space_parser>
        {
            template <typename IteratorT, typename ParserT>
            static parse_info<IteratorT>
            parse(
                IteratorT const&    first_,
                IteratorT const&    last,
                ParserT const&      p,
                space_parser const&)
            {
                typedef skipper_iteration_policy<> iter_policy_t;
                typedef scanner_policies<iter_policy_t> scanner_policies_t;
                typedef scanner<IteratorT, scanner_policies_t> scanner_t;

                IteratorT first = first_;
                scanner_t scan(first, last);
                match<nil_t> hit = p.parse(scan);
                return parse_info<IteratorT>(
                    first, hit, hit && (first == last), hit.length());
            }
        };
    }

///////////////////////////////////////////////////////////////////////////////
//
//  Free parse functions using the skippers
//
///////////////////////////////////////////////////////////////////////////////
template <typename IteratorT, typename ParserT, typename SkipT>
inline parse_info<IteratorT>
parse(
    IteratorT const&        first,
    IteratorT const&        last,
    parser<ParserT> const&  p,
    parser<SkipT> const&    skip)
{
    return impl::phrase_parser<SkipT>::
        parse(first, last, p.derived(), skip.derived());
}

///////////////////////////////////////////////////////////////////////////////
//
//  Parse function for null terminated strings using the skippers
//
///////////////////////////////////////////////////////////////////////////////
template <typename CharT, typename ParserT, typename SkipT>
inline parse_info<CharT const*>
parse(
    CharT const*            str,
    parser<ParserT> const&  p,
    parser<SkipT> const&    skip)
{
    CharT const* last = str;
    while (*last)
        last++;
    return parse(str, last, p, skip);
}

///////////////////////////////////////////////////////////////////////////////
}} // namespace boost::spirit

#endif

