boost/spirit/home/karma/char/char_class.hpp
// Copyright (c) 2001-2011 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_CHAR_CLASS_AUG_10_2009_0720AM)
#define BOOST_SPIRIT_KARMA_CHAR_CLASS_AUG_10_2009_0720AM
#if defined(_MSC_VER)
#pragma once
#endif
#include <boost/spirit/home/support/common_terminals.hpp>
#include <boost/spirit/home/support/string_traits.hpp>
#include <boost/spirit/home/support/info.hpp>
#include <boost/spirit/home/support/char_class.hpp>
#include <boost/spirit/home/support/detail/get_encoding.hpp>
#include <boost/spirit/home/karma/domain.hpp>
#include <boost/spirit/home/karma/meta_compiler.hpp>
#include <boost/spirit/home/karma/delimit_out.hpp>
#include <boost/spirit/home/karma/char/char_generator.hpp>
#include <boost/spirit/home/karma/auxiliary/lazy.hpp>
#include <boost/spirit/home/karma/detail/get_casetag.hpp>
#include <boost/spirit/home/karma/detail/generate_to.hpp>
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit
{
///////////////////////////////////////////////////////////////////////////
// Enablers
///////////////////////////////////////////////////////////////////////////
// enables alnum, alpha, graph, etc.
template <typename CharClass, typename CharEncoding>
struct use_terminal<karma::domain
, tag::char_code<CharClass, CharEncoding> >
: mpl::true_ {};
}}
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit { namespace karma
{
// hoist the char classification namespaces into karma sub-namespaces of
// the same name
namespace ascii { using namespace boost::spirit::ascii; }
namespace iso8859_1 { using namespace boost::spirit::iso8859_1; }
namespace standard { using namespace boost::spirit::standard; }
namespace standard_wide { using namespace boost::spirit::standard_wide; }
#if defined(BOOST_SPIRIT_UNICODE)
namespace unicode { using namespace boost::spirit::unicode; }
#endif
// Import the standard namespace into the karma namespace. This allows
// for default handling of all character/string related operations if not
// prefixed with a character set namespace.
using namespace boost::spirit::standard;
// Import encoding
using spirit::encoding;
///////////////////////////////////////////////////////////////////////////
//
// char_class
// generates a single character if it matches the given character
// class
//
///////////////////////////////////////////////////////////////////////////
template <typename Tag, typename CharEncoding, typename CharClass>
struct char_class
: char_generator<
char_class<Tag, CharEncoding, CharClass>
, CharEncoding, CharClass>
{
typedef typename Tag::char_encoding char_encoding;
typedef typename char_encoding::char_type char_type;
typedef typename Tag::char_class classification;
template <typename Context, typename Unused>
struct attribute
{
typedef char_type type;
};
// char_class needs an attached attribute
template <typename Attribute, typename CharParam, typename Context>
bool test(Attribute const& attr, CharParam& ch, Context&) const
{
ch = attr;
using spirit::char_class::classify;
return classify<char_encoding>::is(classification(), attr);
}
// char_class shouldn't be used without any associated attribute
template <typename CharParam, typename Context>
bool test(unused_type, CharParam&, Context&) const
{
// It is not possible (doesn't make sense) to use char_ generators
// without providing any attribute, as the generator doesn't 'know'
// what to output. The following assertion fires if this situation
// is detected in your code.
BOOST_SPIRIT_ASSERT_FAIL(CharParam
, char_class_not_usable_without_attribute, ());
return false;
}
template <typename Context>
static info what(Context const& /*context*/)
{
typedef spirit::char_class::what<char_encoding> what_;
return info(what_::is(classification()));
}
};
///////////////////////////////////////////////////////////////////////////
//
// space
// generates a single character from the associated parameter
//
///////////////////////////////////////////////////////////////////////////
template <typename CharEncoding>
struct any_space
: char_generator<any_space<CharEncoding>, CharEncoding, tag::space>
{
typedef typename CharEncoding::char_type char_type;
typedef CharEncoding char_encoding;
template <typename Context, typename Unused>
struct attribute
{
typedef char_type type;
};
// any_space has an attached parameter
template <typename Attribute, typename CharParam, typename Context>
bool test(Attribute const& attr, CharParam& ch, Context&) const
{
ch = CharParam(attr);
using spirit::char_class::classify;
return classify<char_encoding>::is(tag::space(), attr);
}
// any_space has no attribute attached, use single space character
template <typename CharParam, typename Context>
bool test(unused_type, CharParam& ch, Context&) const
{
ch = ' ';
return true;
}
template <typename Context>
static info what(Context const& /*context*/)
{
return info("space");
}
};
///////////////////////////////////////////////////////////////////////////
// Generator generators: make_xxx function (objects)
///////////////////////////////////////////////////////////////////////////
namespace detail
{
template <typename Tag, bool lower = false, bool upper = false>
struct make_char_class : mpl::identity<Tag> {};
template <>
struct make_char_class<tag::alpha, true, false>
: mpl::identity<tag::lower> {};
template <>
struct make_char_class<tag::alpha, false, true>
: mpl::identity<tag::upper> {};
template <>
struct make_char_class<tag::alnum, true, false>
: mpl::identity<tag::lowernum> {};
template <>
struct make_char_class<tag::alnum, false, true>
: mpl::identity<tag::uppernum> {};
}
// enables alnum, alpha, graph, etc.
template <typename CharClass, typename CharEncoding, typename Modifiers>
struct make_primitive<tag::char_code<CharClass, CharEncoding>, Modifiers>
{
static bool const lower =
has_modifier<Modifiers, tag::char_code_base<tag::lower> >::value;
static bool const upper =
has_modifier<Modifiers, tag::char_code_base<tag::upper> >::value;
typedef tag::char_code<
typename detail::make_char_class<CharClass, lower, upper>::type
, CharEncoding>
tag_type;
typedef char_class<
tag_type
, typename spirit::detail::get_encoding_with_case<
Modifiers, CharEncoding, lower || upper>::type
, typename detail::get_casetag<Modifiers, lower || upper>::type
> result_type;
result_type operator()(unused_type, unused_type) const
{
return result_type();
}
};
// space is special
template <typename CharEncoding, typename Modifiers>
struct make_primitive<tag::char_code<tag::space, CharEncoding>, Modifiers>
{
typedef any_space<CharEncoding> result_type;
result_type operator()(unused_type, unused_type) const
{
return result_type();
}
};
}}} // namespace boost::spirit::karma
#endif // !defined(BOOST_SPIRIT_KARMA_CHAR_FEB_21_2007_0543PM)