Boost C++ Libraries

boost/spirit/home/karma/detail/generate.hpp

//  Copyright (c) 2001-2010 Hartmut Kaiser
// 
//  Distributed under the Boost Software License, Version 1.0. (See accompanying 
//  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)

#if !defined(BOOST_SPIRIT_KARMA_DETAIL_GENERATE_FEB_20_2007_0959AM)
#define BOOST_SPIRIT_KARMA_DETAIL_GENERATE_FEB_20_2007_0959AM

#if defined(_MSC_VER)
#pragma once
#endif

#include <boost/spirit/home/karma/meta_compiler.hpp>
#include <boost/spirit/home/karma/delimit_out.hpp>
#include <boost/spirit/home/karma/delimit_flag.hpp>
#include <boost/spirit/home/karma/detail/output_iterator.hpp>
#include <boost/spirit/home/support/unused.hpp>
#include <boost/mpl/assert.hpp>
#include <boost/mpl/bool.hpp>

namespace boost { namespace spirit { namespace karma { namespace detail
{
    ///////////////////////////////////////////////////////////////////////////
    template <typename Expr, typename Enable = void>
    struct generate_impl
    {
        // Report invalid expression error as early as possible.
        // If you got an error_invalid_expression error message here,
        // then the expression (Expr) is not a valid spirit karma expression.
        // Did you intend to use the auto_ facilities while forgetting to 
        // #include <boost/spirit/include/karma_auto.hpp>?
        BOOST_SPIRIT_ASSERT_MATCH(karma::domain, Expr);
    };

    template <typename Expr>
    struct generate_impl<Expr
      , typename enable_if<traits::matches<karma::domain, Expr> >::type>
    {
        template <typename OutputIterator>
        static bool call(
            OutputIterator& target_sink
          , Expr const& expr)
        {
            typedef traits::properties_of<
                typename result_of::compile<karma::domain, Expr>::type
            > properties;

            // wrap user supplied iterator into our own output iterator
            output_iterator<OutputIterator
              , mpl::int_<properties::value> > sink(target_sink);
            return compile<karma::domain>(expr).
                generate(sink, unused, unused, unused);
        }

        template <typename OutputIterator, typename Properties>
        static bool call(
            detail::output_iterator<OutputIterator, Properties>& sink
          , Expr const& expr)
        {
            return compile<karma::domain>(expr).
                generate(sink, unused, unused, unused);
        }
    };

    ///////////////////////////////////////////////////////////////////////////
    template <typename Expr, typename Enable = void>
    struct generate_delimited_impl
    {
        // Report invalid expression error as early as possible.
        // If you got an error_invalid_expression error message here,
        // then the expression (Expr) is not a valid spirit karma expression.
        // Did you intend to use the auto_ facilities while forgetting to 
        // #include <boost/spirit/include/karma_auto.hpp>?
        BOOST_SPIRIT_ASSERT_MATCH(karma::domain, Expr);
    };

    template <typename Expr>
    struct generate_delimited_impl<Expr
      , typename enable_if<traits::matches<karma::domain, Expr> >::type>
    {
        template <typename OutputIterator, typename Delimiter>
        static bool call(
            OutputIterator& target_sink
          , Expr const& expr
          , Delimiter const& delimiter
          , BOOST_SCOPED_ENUM(delimit_flag) pre_delimit)
        {
            typedef traits::properties_of<
                typename result_of::compile<karma::domain, Expr>::type
            > properties;
            typedef traits::properties_of<
                typename result_of::compile<karma::domain, Delimiter>::type
            > delimiter_properties;

            // wrap user supplied iterator into our own output iterator
            detail::output_iterator<OutputIterator
              , mpl::int_<properties::value | delimiter_properties::value>
            > sink(target_sink);
            return call(sink, expr, delimiter, pre_delimit);
        }

        template <typename OutputIterator, typename Properties
          , typename Delimiter>
        static bool call(
            detail::output_iterator<OutputIterator, Properties>& sink
          , Expr const& expr
          , Delimiter const& delimiter
          , BOOST_SCOPED_ENUM(delimit_flag) pre_delimit)
        {
            // Report invalid expression error as early as possible.
            // If you got an error_invalid_expression error message here,
            // then the delimiter is not a valid spirit karma expression.
            BOOST_SPIRIT_ASSERT_MATCH(karma::domain, Delimiter);

            typename result_of::compile<karma::domain, Delimiter>::type const 
                delimiter_ = compile<karma::domain>(delimiter);

            if (pre_delimit == delimit_flag::predelimit &&
                !karma::delimit_out(sink, delimiter_))
            {
                return false;
            }
            return compile<karma::domain>(expr).
                generate(sink, unused, delimiter_, unused);
        }
    };

}}}}

#endif