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