karma/detail/generate.hpp

0001 //  Copyright (c) 2001-2011 Hartmut Kaiser
0002 //
0003 //  Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 //  file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005
0006 #if !defined(BOOST_SPIRIT_KARMA_DETAIL_GENERATE_FEB_20_2007_0959AM)
0007 #define BOOST_SPIRIT_KARMA_DETAIL_GENERATE_FEB_20_2007_0959AM
0008
0009 #if defined(_MSC_VER)
0010 #pragma once
0011 #endif
0012
0013 #include <boost/spirit/home/karma/meta_compiler.hpp>
0014 #include <boost/spirit/home/karma/delimit_out.hpp>
0015 #include <boost/spirit/home/karma/delimit_flag.hpp>
0016 #include <boost/spirit/home/karma/detail/output_iterator.hpp>
0017 #include <boost/spirit/home/support/unused.hpp>
0018 #include <boost/mpl/assert.hpp>
0019 #include <boost/mpl/bool.hpp>
0020
0021 namespace boost { namespace spirit { namespace karma { namespace detail
0022 {
0023     ///////////////////////////////////////////////////////////////////////////
0024     template <typename Expr, typename Enable = void>
0025     struct generate_impl
0026     {
0027         // Report invalid expression error as early as possible.
0028         // If you got an error_invalid_expression error message here,
0029         // then the expression (Expr) is not a valid spirit karma expression.
0030         // Did you intend to use the auto_ facilities while forgetting to
0031         // #include <boost/spirit/include/karma_auto.hpp>?
0032         BOOST_SPIRIT_ASSERT_MATCH(karma::domain, Expr);
0033     };
0034
0035     template <typename Expr>
0036     struct generate_impl<Expr
0037       , typename enable_if<traits::matches<karma::domain, Expr> >::type>
0038     {
0039         template <typename OutputIterator>
0040         static bool call(
0041             OutputIterator& target_sink
0042           , Expr const& expr)
0043         {
0044             typedef traits::properties_of<
0045                 typename result_of::compile<karma::domain, Expr>::type
0046             > properties;
0047
0048             // wrap user supplied iterator into our own output iterator
0049             output_iterator<OutputIterator
0050               , mpl::int_<properties::value> > sink(target_sink);
0051             return compile<karma::domain>(expr).
0052                 generate(sink, unused, unused, unused);
0053         }
0054
0055         template <typename OutputIterator, typename Properties>
0056         static bool call(
0057             detail::output_iterator<OutputIterator, Properties>& sink
0058           , Expr const& expr)
0059         {
0060             return compile<karma::domain>(expr).
0061                 generate(sink, unused, unused, unused);
0062         }
0063     };
0064
0065     ///////////////////////////////////////////////////////////////////////////
0066     template <typename Expr, typename Enable = void>
0067     struct generate_delimited_impl
0068     {
0069         // Report invalid expression error as early as possible.
0070         // If you got an error_invalid_expression error message here,
0071         // then the expression (Expr) is not a valid spirit karma expression.
0072         // Did you intend to use the auto_ facilities while forgetting to
0073         // #include <boost/spirit/include/karma_auto.hpp>?
0074         BOOST_SPIRIT_ASSERT_MATCH(karma::domain, Expr);
0075     };
0076
0077     template <typename Expr>
0078     struct generate_delimited_impl<Expr
0079       , typename enable_if<traits::matches<karma::domain, Expr> >::type>
0080     {
0081         template <typename OutputIterator, typename Delimiter>
0082         static bool call(
0083             OutputIterator& target_sink
0084           , Expr const& expr
0085           , Delimiter const& delimiter
0086           , BOOST_SCOPED_ENUM(delimit_flag) pre_delimit)
0087         {
0088             typedef traits::properties_of<
0089                 typename result_of::compile<karma::domain, Expr>::type
0090             > properties;
0091             typedef traits::properties_of<
0092                 typename result_of::compile<karma::domain, Delimiter>::type
0093             > delimiter_properties;
0094
0095             // wrap user supplied iterator into our own output iterator
0096             detail::output_iterator<OutputIterator
0097               , mpl::int_<properties::value | delimiter_properties::value>
0098             > sink(target_sink);
0099             return call(sink, expr, delimiter, pre_delimit);
0100         }
0101
0102         template <typename OutputIterator, typename Properties
0103           , typename Delimiter>
0104         static bool call(
0105             detail::output_iterator<OutputIterator, Properties>& sink
0106           , Expr const& expr
0107           , Delimiter const& delimiter
0108           , BOOST_SCOPED_ENUM(delimit_flag) pre_delimit)
0109         {
0110             // Report invalid expression error as early as possible.
0111             // If you got an error_invalid_expression error message here,
0112             // then the delimiter is not a valid spirit karma expression.
0113             BOOST_SPIRIT_ASSERT_MATCH(karma::domain, Delimiter);
0114
0115             typename result_of::compile<karma::domain, Delimiter>::type const
0116                 delimiter_ = compile<karma::domain>(delimiter);
0117
0118             if (pre_delimit == delimit_flag::predelimit &&
0119                 !karma::delimit_out(sink, delimiter_))
0120             {
0121                 return false;
0122             }
0123             return compile<karma::domain>(expr).
0124                 generate(sink, unused, delimiter_, unused);
0125         }
0126     };
0127
0128 }}}}
0129
0130 #endif
0131