Chris@16: /*=============================================================================
Chris@16:     Copyright (c) 2001-2003 Daniel Nuffer
Chris@16:     http://spirit.sourceforge.net/
Chris@16: 
Chris@16:   Distributed under the Boost Software License, Version 1.0. (See accompanying
Chris@16:   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: =============================================================================*/
Chris@16: #ifndef BOOST_SPIRIT_ESCAPE_CHAR_HPP
Chris@16: #define BOOST_SPIRIT_ESCAPE_CHAR_HPP
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: #include <string>
Chris@16: #include <iterator>
Chris@16: #include <cctype>
Chris@16: #include <boost/limits.hpp>
Chris@16: 
Chris@16: #include <boost/spirit/home/classic/namespace.hpp>
Chris@16: #include <boost/spirit/home/classic/debug.hpp>
Chris@16: 
Chris@16: #include <boost/spirit/home/classic/utility/escape_char_fwd.hpp>
Chris@16: #include <boost/spirit/home/classic/utility/impl/escape_char.ipp>
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: namespace boost { namespace spirit {
Chris@16: 
Chris@16: BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  escape_char_action class
Chris@16: //
Chris@16: //      Links an escape char parser with a user defined semantic action.
Chris@16: //      The semantic action may be a function or a functor. A function
Chris@16: //      should be compatible with the interface:
Chris@16: //
Chris@16: //          void f(CharT ch);
Chris@16: //
Chris@16: //      A functor should have a member operator() with a compatible signature
Chris@16: //      as above. The matching character is passed into the function/functor.
Chris@16: //      This is the default class that character parsers use when dealing with
Chris@16: //      the construct:
Chris@16: //
Chris@16: //          p[f]
Chris@16: //
Chris@16: //      where p is a parser and f is a function or functor.
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: template <
Chris@16:     typename ParserT, typename ActionT,
Chris@16:     unsigned long Flags, typename CharT
Chris@16: >
Chris@16: struct escape_char_action
Chris@16: :   public unary<ParserT,
Chris@16:         parser<escape_char_action<ParserT, ActionT, Flags, CharT> > >
Chris@16: {
Chris@16:     typedef escape_char_action
Chris@16:         <ParserT, ActionT, Flags, CharT>        self_t;
Chris@16:     typedef action_parser_category              parser_category_t;
Chris@16:     typedef unary<ParserT, parser<self_t> >     base_t;
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     struct result
Chris@16:     {
Chris@16:         typedef typename match_result<ScannerT, CharT>::type type;
Chris@16:     };
Chris@16: 
Chris@16:     escape_char_action(ParserT const& p, ActionT const& a)
Chris@16:     : base_t(p), actor(a) {}
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     typename parser_result<self_t, ScannerT>::type
Chris@16:     parse(ScannerT const& scan) const
Chris@16:     {
Chris@16:         return impl::escape_char_action_parse<Flags, CharT>::
Chris@16:             parse(scan, *this);
Chris@16:     }
Chris@16: 
Chris@16:     ActionT const& predicate() const { return actor; }
Chris@16: 
Chris@16: private:
Chris@16: 
Chris@16:     ActionT actor;
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  escape_char_parser class
Chris@16: //
Chris@16: //      The escape_char_parser helps in conjunction with the escape_char_action
Chris@16: //      template class (see above) in parsing escaped characters. There are two
Chris@16: //      different variants of this parser: one for parsing C style escaped
Chris@16: //      characters and one for parsing LEX style escaped characters.
Chris@16: //
Chris@16: //      The C style escaped character parser is generated, when the template
Chris@16: //      parameter 'Flags' is equal to 'c_escapes' (a constant defined in the
Chris@16: //      file impl/escape_char.ipp). This parser recognizes all valid C escape
Chris@16: //      character sequences: '\t', '\b', '\f', '\n', '\r', '\"', '\'', '\\'
Chris@16: //      and the numeric style escapes '\120' (octal) and '\x2f' (hexadecimal)
Chris@16: //      and converts these to their character equivalent, for instance the
Chris@16: //      sequence of a backslash and a 'b' is parsed as the character '\b'.
Chris@16: //      All other escaped characters are rejected by this parser.
Chris@16: //
Chris@16: //      The LEX style escaped character parser is generated, when the template
Chris@16: //      parameter 'Flags' is equal to 'lex_escapes' (a constant defined in the
Chris@16: //      file impl/escape_char.ipp). This parser recognizes all the C style
Chris@16: //      escaped character sequences (as described above) and additionally
Chris@16: //      does not reject all other escape sequences. All not mentioned escape
Chris@16: //      sequences are converted by the parser to the plain character, for
Chris@16: //      instance '\a' will be parsed as 'a'.
Chris@16: //
Chris@16: //      All not escaped characters are parsed without modification.
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: 
Chris@16: template <unsigned long Flags, typename CharT>
Chris@16: struct escape_char_action_parser_gen;
Chris@16: 
Chris@16: template <unsigned long Flags, typename CharT>
Chris@16: struct escape_char_parser :
Chris@16:     public parser<escape_char_parser<Flags, CharT> > {
Chris@16: 
Chris@16:     // only the values c_escapes and lex_escapes are valid for Flags
Chris@16:     BOOST_STATIC_ASSERT(Flags == c_escapes || Flags == lex_escapes);
Chris@16: 
Chris@16:     typedef escape_char_parser<Flags, CharT> self_t;
Chris@16:     typedef
Chris@16:         escape_char_action_parser_gen<Flags, CharT>
Chris@16:         action_parser_generator_t;
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     struct result {
Chris@16: 
Chris@16:         typedef typename match_result<ScannerT, CharT>::type type;
Chris@16:     };
Chris@16: 
Chris@16:     template <typename ActionT>
Chris@16:     escape_char_action<self_t, ActionT, Flags, CharT>
Chris@16:     operator[](ActionT const& actor) const
Chris@16:     {
Chris@16:         return escape_char_action<self_t, ActionT, Flags, CharT>(*this, actor);
Chris@16:     }
Chris@16: 
Chris@16:     template <typename ScannerT>
Chris@16:     typename parser_result<self_t, ScannerT>::type
Chris@16:     parse(ScannerT const &scan) const
Chris@16:     {
Chris@16:         return impl::escape_char_parse<CharT>::parse(scan, *this);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: template <unsigned long Flags, typename CharT>
Chris@16: struct escape_char_action_parser_gen {
Chris@16: 
Chris@16:     template <typename ParserT, typename ActionT>
Chris@16:     static escape_char_action<ParserT, ActionT, Flags, CharT>
Chris@16:     generate (ParserT const &p, ActionT const &actor)
Chris@16:     {
Chris@16:         typedef
Chris@16:             escape_char_action<ParserT, ActionT, Flags, CharT>
Chris@16:             action_parser_t;
Chris@16:         return action_parser_t(p, actor);
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: //
Chris@16: //  predefined escape_char_parser objects
Chris@16: //
Chris@16: //      These objects should be used for generating correct escaped character
Chris@16: //      parsers.
Chris@16: //
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: const escape_char_parser<lex_escapes> lex_escape_ch_p =
Chris@16:     escape_char_parser<lex_escapes>();
Chris@16: 
Chris@16: const escape_char_parser<c_escapes> c_escape_ch_p =
Chris@16:     escape_char_parser<c_escapes>();
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: BOOST_SPIRIT_CLASSIC_NAMESPACE_END
Chris@16: 
Chris@16: }} // namespace BOOST_SPIRIT_CLASSIC_NS
Chris@16: 
Chris@16: #endif