ceph/src/boost/libs/spirit/example/support/utree/sexpr_generator.hpp

   1 /*==============================================================================
   2     Copyright (c) 2001-2011 Hartmut Kaiser
   3     Copyright (c) 2010-2011 Bryce Lelbach
   4
   5     Distributed under the Boost Software License, Version 1.0. (See accompanying
   6     file BOOST_LICENSE_1_0.rst or copy at http://www.boost.org/LICENSE_1_0.txt)
   7 ==============================================================================*/
   8
   9 #if !defined(BOOST_SPIRIT_UTREE_EXAMPLE_SEXPR_GENERATOR_HPP)
  10 #define BOOST_SPIRIT_UTREE_EXAMPLE_SEXPR_GENERATOR_HPP
  11
  12 #include <boost/spirit/include/support_utree.hpp>
  13 #include <boost/spirit/include/karma.hpp>
  14
  15 namespace boost {
  16 namespace spirit {
  17 namespace traits {
  18
  19 template<>
  20 struct transform_attribute<utree::nil_type, unused_type, karma::domain> {
  21   typedef unused_type type;
  22
  23   static unused_type pre (utree::nil_type&) { return unused_type(); }
  24 };
  25
  26 } // traits
  27 } // spirit
  28 } // boost
  29
  30 namespace sexpr
  31 {
  32
  33 namespace karma = boost::spirit::karma;
  34 namespace standard = boost::spirit::standard;
  35
  36 using boost::spirit::utree;
  37 using boost::spirit::utf8_symbol_range_type;
  38 using boost::spirit::utf8_string_range_type;
  39 using boost::spirit::binary_range_type;
  40
  41 struct bool_output_policies : karma::bool_policies<>
  42 {
  43     template <typename CharEncoding, typename Tag, typename Iterator>
  44     static bool generate_true(Iterator& sink, bool)
  45     {
  46         return string_inserter<CharEncoding, Tag>::call(sink, "#t");
  47     }
  48
  49     template <typename CharEncoding, typename Tag, typename Iterator>
  50     static bool generate_false(Iterator& sink, bool)
  51     {
  52         return string_inserter<CharEncoding, Tag>::call(sink, "#f");
  53     }
  54 };
  55
  56 template <typename Iterator>
  57 struct generator : karma::grammar<Iterator, utree()>
  58 {
  59     typedef boost::iterator_range<utree::const_iterator> utree_list;
  60
  61     karma::rule<Iterator, utree()>
  62         start, ref_;
  63
  64     karma::rule<Iterator, utree_list()>
  65         list;
  66
  67     karma::rule<Iterator, utf8_symbol_range_type()>
  68         symbol;
  69
  70     karma::rule<Iterator, utree::nil_type()>
  71         nil_;
  72
  73     karma::rule<Iterator, utf8_string_range_type()>
  74         utf8;
  75
  76     karma::rule<Iterator, binary_range_type()>
  77         binary;
  78
  79     generator() : generator::base_type(start)
  80     {
  81         using standard::char_;
  82         using standard::string;
  83         using karma::bool_generator;
  84         using karma::uint_generator;
  85         using karma::double_;
  86         using karma::int_;
  87         using karma::lit;
  88         using karma::right_align;
  89
  90         uint_generator<unsigned char, 16> hex2;
  91         bool_generator<bool, bool_output_policies> boolean;
  92
  93         start = nil_
  94               | double_
  95               | int_
  96               | boolean
  97               | utf8
  98               | symbol
  99               | binary
 100               | list
 101               | ref_;
 102
 103         ref_ = start;
 104
 105         list = '(' << -(start % ' ') << ')';
 106
 107         utf8 = '"' << *(&char_('"') << "\\\"" | char_) << '"';
 108
 109         symbol = string;
 110
 111         binary = '#' << *right_align(2, '0')[hex2] << '#';
 112
 113         nil_ = karma::attr_cast(lit("nil"));
 114
 115         start.name("sexpr");
 116         ref_.name("ref");
 117         list.name("list");
 118         utf8.name("string");
 119         symbol.name("symbol");
 120         binary.name("binary");
 121         nil_.name("nil");
 122     }
 123 };
 124
 125 } // sexpr
 126
 127 #endif // BOOST_SPIRIT_UTREE_EXAMPLE_SEXPR_GENERATOR_HPP
 128