boost/spirit/symbols/symbols.hpp
/*=============================================================================
Copyright (c) 2001-2003 Joel de Guzman
http://spirit.sourceforge.net/
Use, modification and distribution is subject to 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_SYMBOLS_HPP
#define BOOST_SPIRIT_SYMBOLS_HPP
///////////////////////////////////////////////////////////////////////////////
#include <string>
#include <boost/ref.hpp>
#include <boost/spirit/core/parser.hpp>
#include <boost/spirit/core/composite/directives.hpp>
///////////////////////////////////////////////////////////////////////////////
namespace boost { namespace spirit {
///////////////////////////////////////////////////////////////////////////////
// Forward Declarations
namespace impl
{
template <typename CharT, typename T>
class tst;
}
template <typename T, typename SetT>
class symbol_inserter;
///////////////////////////////////////////////////////////////////////////////
//
// symbols class
//
// This class implements a symbol table. The symbol table holds a
// dictionary of symbols where each symbol is a sequence of CharTs.
// The template class can work efficiently with 8, 16 and 32 bit
// characters. Mutable data of type T is associated with each
// symbol.
//
// The class is a parser. The parse member function returns
// additional information in the symbol_match class (see below).
// The additional data is a pointer to some data associated with
// the matching symbol.
//
// The actual set implementation is supplied by the SetT template
// parameter. By default, this uses the tst class (see tst.ipp).
//
// Symbols are added into the symbol table statically using the
// construct:
//
// sym = a, b, c, d ...;
//
// where sym is a symbol table and a..d are strings. Example:
//
// sym = "pineapple", "orange", "banana", "apple";
//
// Alternatively, symbols may be added dynamically through the
// member functor 'add' (see symbol_inserter below). The member
// functor 'add' may be attached to a parser as a semantic action
// taking in a begin/end pair:
//
// p[sym.add]
//
// where p is a parser (and sym is a symbol table). On success,
// the matching portion of the input is added to the symbol table.
//
// 'add' may also be used to directly initialize data. Examples:
//
// sym.add("hello", 1)("crazy", 2)("world", 3);
//
///////////////////////////////////////////////////////////////////////////////
template
<
typename T = int,
typename CharT = char,
typename SetT = impl::tst<T, CharT>
>
class symbols
: private SetT
, public parser<symbols<T, CharT, SetT> >
{
public:
typedef parser<symbols<T, CharT, SetT> > parser_base_t;
typedef symbols<T, CharT, SetT> self_t;
typedef self_t const& embed_t;
typedef T symbol_data_t;
typedef boost::reference_wrapper<T> symbol_ref_t;
symbols();
symbols(symbols const& other);
~symbols();
symbols&
operator=(symbols const& other);
symbol_inserter<T, SetT> const&
operator=(CharT const* str);
template <typename ScannerT>
struct result
{
typedef typename match_result<ScannerT, symbol_ref_t>::type type;
};
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse_main(ScannerT const& scan) const
{
typedef typename ScannerT::iterator_t iterator_t;
iterator_t first = scan.first;
typename SetT::search_info result = SetT::find(scan);
if (result.data)
return scan.
create_match(
result.length,
symbol_ref_t(*result.data),
first,
scan.first);
else
return scan.no_match();
}
template <typename ScannerT>
typename parser_result<self_t, ScannerT>::type
parse(ScannerT const& scan) const
{
typedef typename parser_result<self_t, ScannerT>::type result_t;
return impl::implicit_lexeme_parse<result_t>
(*this, scan, scan);
}
template < typename ScannerT >
T* find(ScannerT const& scan) const
{ return SetT::find(scan).data; }
symbol_inserter<T, SetT> const add;
};
///////////////////////////////////////////////////////////////////////////////
//
// Symbol table utilities
//
// add
//
// adds a symbol 'sym' (string) to a symbol table 'table' plus an
// optional data 'data' associated with the symbol. Returns a pointer to
// the data associated with the symbol or NULL if add failed (e.g. when
// the symbol is already added before).
//
// find
//
// finds a symbol 'sym' (string) from a symbol table 'table'. Returns a
// pointer to the data associated with the symbol or NULL if not found
//
///////////////////////////////////////////////////////////////////////////////
template <typename T, typename CharT, typename SetT>
T* add(symbols<T, CharT, SetT>& table, CharT const* sym, T const& data = T());
template <typename T, typename CharT, typename SetT>
T* find(symbols<T, CharT, SetT> const& table, CharT const* sym);
///////////////////////////////////////////////////////////////////////////////
//
// symbol_inserter class
//
// The symbols class holds an instance of this class named 'add'.
// This can be called directly just like a member function,
// passing in a first/last iterator and optional data:
//
// sym.add(first, last, data);
//
// Or, passing in a C string and optional data:
//
// sym.add(c_string, data);
//
// where sym is a symbol table. The 'data' argument is optional.
// This may also be used as a semantic action since it conforms
// to the action interface (see action.hpp):
//
// p[sym.add]
//
///////////////////////////////////////////////////////////////////////////////
template <typename T, typename SetT>
class symbol_inserter
{
public:
symbol_inserter(SetT& set_)
: set(set_) {}
template <typename IteratorT>
symbol_inserter const&
operator()(IteratorT first, IteratorT const& last, T const& data = T()) const
{
set.add(first, last, data);
return *this;
}
template <typename CharT>
symbol_inserter const&
operator()(CharT const* str, T const& data = T()) const
{
CharT const* last = str;
while (*last)
last++;
set.add(str, last, data);
return *this;
}
template <typename CharT>
symbol_inserter const&
operator,(CharT const* str) const
{
CharT const* last = str;
while (*last)
last++;
set.add(str, last, T());
return *this;
}
private:
SetT& set;
};
///////////////////////////////////////////////////////////////////////////////
}} // namespace boost::spirit
#include <boost/spirit/symbols/impl/symbols.ipp>
#endif
